Antimicrobial activity of silver-carbon nanoparticles on the bacterial flora of bull semen.

The spermicidal effects of silver nanoparticles (AgNPs) hinder its application in the field of artificial insemination. In this study, silver-carbon NPs (Ag@C NPs) was synthesized and applied as an alternative antibiotic agent for bull semen extender. Ag@C NPs were characterized using X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), atomic absorption flame spectroscopy, transmission electron microscope (TEM), and high-resolution TEM (HR-TEM). Data analysis revealed the successful synthesis of Ag@C NPs with a particle size of 1-5 nm (average particle size of 2.5 nm) embedded into carbon. The antimicrobial activity of Ag@C NPs was tested against bacteriospermia of fresh semen collected from five fertile bulls (three ejaculates/bull). Escherichia coli (E. Coli), Staphylococcus aureus (S. aureus), and Pseudomonas aeruginosa (P. aeruginosa) were isolated from fresh semen samples and identified by culture, staining, and conventional biochemical tests. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of Ag@C NPs against bacteriospermia was determined at 5 and 37 °C. Ag@C NPs showed efficient antimicrobial activity (MIC: 3.125-12.5 µg/mL) against the tested strains and strong bactericidal effect on S. aureus, and P. aeruginosa (MBC: 3.125 µg/mL), with no detrimental effect (P ˃ 0.05) on the percentage of sperm motility (70.71 ± 4.82; 74.65 ± 4.46), plasma membrane integrity (68.39 ± 4.31; 72.38 ± 4.91), acrosome integrity (88.40 ± 13.21; 86.77 ± 14.23), and normal sperm morphology (86.85 ± 7.43; 87.82 ± 8.15) at concentrations of 15 and 30 µg/mL, respectively, after a cold storage of 48 h. However, Ag@C NPs showed a detrimental effect on sperm parameters in a dose dependent manner at concentrations ≥60 µg/mL. Ag@C NPs showed no adverse effect on the sperm's ultrastructure with limited sperm internalization at MIC. In conclusion, Ag@C NPs could be used as an alternative antibiotic agent for bull semen extender without a significant cytotoxic effect on the sperm during cold storage. However, further investigations for their effects on embryo production and female genitalia are still required.

Climate Change and Inpatient Dermatology.

PURPOSE OF REVIEW: Climate change represents a major existential threat facing the global community, and it has already begun to affect human health in a multitude of ways. This review highlights and discusses the implications that climate change has already had and is expected to have for inpatient dermatologists. RECENT FINDINGS: There are a variety of conditions affected by climate changes. The distribution and frequencies of infectious diseases and their vectors are changing in line with variations in climate conditions. Increased temperatures have already been associated with exacerbation of existing skin conditions, such as atopic dermatitis, and recent evidence suggests that higher temperatures will also magnify the effects of harmful ultraviolet radiation. Extreme weather events that result from climate change are followed by an array of dermatologic conditions that may be unusual for the given location. Inpatient dermatologists should be prepared to manage these potentially unfamiliar dermatologic consequences of climate change. SUMMARY: Climate change will have widespread effects on the medical field, and inpatient dermatologists will be faced with their own unique set of challenges and practice variations. Practitioners should be familiar with the ongoing and predicted effects of climate change in their locations so that they can readily identify and treat associated conditions, and they should adjust their practice to reduce their carbon footprint and serve as a model for patients to do the same.

Inhibition and recovery of maternal and fetal cholinesterase enzymes following a single oral dose of chlorpyrifos in rats.

Pregnant Sprague-Dawley rats (14-18 days of gestation) were treated with a single dose of 50 mg/kg (61% of oral LD50 in female rats) of chlorpyrifos ( 0,0-diethyl- 0-3,5,6-trichloro-2-pyridyl phosphorothioate) by oral gavage. Animals treated on day 18 of gestation were sacrificed at 1, 2, 4, 12 h after dosing. Animals treated on days 17, 16, 15, and 14 of gestation were sacrificed at 24, 48, 72, and 96 h after dosing, respectively. Maternal and fetal brain acetylcholinesterase (AchE) and plasma butyrylcholinesterase (BuChE) activities were significantly inhibited 1 h after treatment. Activity of fetal brain AChE and plasma BuChE recovered faster than that of the maternal enzymes. Peak inhibition of maternal spinal cord AChE and BuChE activities occurred 2 h and 1 h after dosing, respectively. Maternal spinal cord BuChE activity was totally recovered by 96 h compared to the partial recovery of spinal cord AChE activity. Maternal liver BuChE activity was significantly decreased within 1 h of dosing. The individual molecular forms (10S and 4S) of maternal and fetal brain AChE and BuChE activities were significantly decreased 1 h after treatment. Recovery of both forms of fetal brain AChE activity was much faster than the maternal forms. Activity of the 10S form of maternal control brain AChE was significantly higher than in the fetus control. The rapid recovery of cholinesterase enzymes in the fetus is attributed to the de novo synthesis of AChE enzymes in the fetus compared to the mother.