scholarly journals A short-term inhalation study to assess the reversibility of sensory irritation in human volunteers

2020 ◽  
Vol 94 (5) ◽  
pp. 1687-1701 ◽  
Author(s):  
Stefan Kleinbeck ◽  
Michael Schäper ◽  
Marlene Pacharra ◽  
Marie Louise Lehmann ◽  
Klaus Golka ◽  
...  
Keyword(s):  
Sensory Irritation ◽  
Short Term ◽  
Inhalation Study ◽  
Human Volunteers

Short‐Term Repeatability of in Vivo Cardiac Intravoxel Incoherent Motion Tensor Imaging in Healthy Human Volunteers

2021 ◽  
Author(s):  
Xiu‐Shi Zhang ◽  
En‐Hui Liu ◽  
Xin‐Yu Wang ◽  
Xin‐Xiang Zhou ◽  
Hong‐Xia Zhang ◽  
...  
Keyword(s):  
Intravoxel Incoherent Motion ◽  
Short Term ◽  
Healthy Human ◽  
Human Volunteers

scholarly journals Accumulation of quercetin conjugates in blood plasma after the short-term ingestion of onion by women

2000 ◽  
Vol 279 (2) ◽  
pp. R461-R467 ◽  
Author(s):  
Jae-Hak Moon ◽  
Ritsuko Nakata ◽  
Syunji Oshima ◽  
Takahiro Inakuma ◽  
Junji Terao
Keyword(s):  
Blood Plasma ◽  
Low Density Lipoprotein ◽  
Copper Ion ◽  
Density Lipoprotein ◽  
Tocopherol Content ◽  
Human Blood Plasma ◽  
Short Term ◽  
Beneficial Effects ◽  
Human Volunteers ◽  
Conjugated Metabolites

Quercetin is a typical flavonoid present mostly as glycosides in plant foods; it has attracted much attention for its potential beneficial effects in disease prevention. In this study, we examined human volunteers after the short-term ingestion of onion, a vegetable rich in quercetin glucosides. The subjects were served diets containing onion slices (quercetin equivalent: 67.6–93.6 mg/day) with meals for 1 wk. Quercetin was only found in glucuronidase-sulfatase-treated plasma, and its concentration after 10 h of fasting increased from 0.04 ± 0.04 μM before the trial to 0.63 ± 0.72 μM after the 1-wk trial. The quercetin content in low-density lipoprotein (LDL) after glucuronidase-sulfatase treatment corresponded to <1% of the α-tocopherol content. Human LDL isolated from the plasma after the trial showed little improvement of its resistance to copper ion-induced oxidation. It is therefore concluded that conjugated metabolites of quercetin accumulate exclusively in human blood plasma in the concentration range of 10−7 ∼ 10−6 M after the short-term ingestion of vegetables rich in quercetin glucosides, although these metabolites are hardly incorporated into plasma LDL.

scholarly journals Final Report on the Safety Assessment of Stearoxy Dimethicone, Dimethicone, Methicone, Amino Bispropyl Dimethicone, Aminopropyl Dimethicone, Amodimethicone, Amodimethicone Hydroxystearate, Behenoxy Dimethicone, C24–28 Alkyl Methicone, C30–45 Alkyl Methicone, C30–45 Alkyl Dimethicone, Cetearyl Methicone, Cetyl Dimethicone, Dimethoxysilyl Ethylenediaminopropyl Dimethicone, Hexyl Methicone, Hydroxypropyldimethicone, Stearamidopropyl Dimethicone, Stearyl Dimethicone, Stearyl Methicone, and Vinyldimethicone

2003 ◽  
Vol 22 (2_suppl) ◽  
pp. 10-35
Keyword(s):  
Adverse Effects ◽  
Expert Panel ◽  
Developmental Toxicity ◽  
Oral Exposure ◽  
Final Report ◽  
Short Term ◽  
Fluid Mixture ◽  
Inhalation Study ◽  
Cosmetic Formulations ◽  
Siloxane Polymers

Dimethicone is a fluid mixture of fully methylated linear siloxane polymers end-blocked with trimethylsiloxy units. Methicone is a linear monomethyl polysiloxane. The other dimethicones and methicones covered in this review are siloxane polymers of Dimethicone and Methicone. Most of these ingredients function as conditioning agents in cosmetic formulations at current concentrations of use of ≤ 15%. Clinical and animal absorption studies reported that Dimethicone was not absorbed following oral or dermal exposure. Dimethicone, Methicone, and Vinyldimethicone were not acutely toxic following oral exposure. No adverse reactions were found in rabbits following short-term dermal dosing with 6% to 79% Dimethicone, yet adverse effects were noted with a hand cream formulation containing 1% Dimethicone, suggesting something else in the preparation was toxic. Mice and rats were dosed for 90 days with up to 10% Dimethicone without adverse effect. Dimethicone did not produce adverse effects in acute and short-term inhalation-route studies, Methicone and Vinyldimethicone were negative in acute exposure studies using rats, but Hexyl Methicone was toxic to rats at 5 mg/L delivered in small particle (mean diameter of 0.29 μ) aerosols. Most dermal irritation studies using rabbits classified Dimethicone as a minimal irritant. Dimethicone (tested undiluted and at 79%) was not a sensitizer in four assays using mice and guinea pigs. It was not a sensitizer at 5.0% in a clinical repeated insult patch test using 83 panelists. Most ocular irritation studies using rabbits classified Dimethicone as a mild to minimal irritant. Dimethicone was tested in numerous oral-dose (using rats) and dermal-dose (using rats, rabbits, and monkeys) reproductive and developmental toxicity studies. In a few studies, treated males had significantly decreased body weight and/or decreased testes or seminal vesicles weights. No treatment-related adverse findings were noted in dosed pregnant females or fetuses. Dimethicone was negative in all genotoxicity assays. It was negative in both an oral (tested at 91%) and dermal (tested at an unknown concentration) dose carcinogenicity assay using mice. The Cosmetic Ingredient Review (CIR) Expert Panel considered it unlikely that any of these polymers would be significantly absorbed into the skin due to their large molecular weight. Although adverse effects were noted in one inhalation study with small aerosol particles, the expected particle sizes for cosmetic products would primarily be in the range of 60 to 80 μ, and less than 1% would be under 10 μ, which is an upper limit for respirable particles. Overall, the safety test data support the safety of these ingredients at the concentrations they are known to be used in cosmetic formulations. Accordingly, the CIR Expert Panel was of the opinion that Stearoxy Dimethicone, Dimethicone, Methicone, Amino Bis-propyl Dimethicone, Aminopropyl Dimethicone, Amodimethicone, Amodimethicone Hydroxystearate, Behenoxy Dimethicone, C24–28 Alkyl Methicone, C30–45 Alkyl Methicone, C30–45 Alkyl Dimethicone, Cetearyl Methicone, Cetyl Dimethicone, Dimethoxysilyl Ethylenediaminopropyl Dimethicone, Hexyl Methicone, Hydroxypropyldimethicone, Stearamidopropyl Dimethicone, Stearyl Dimethicone, Stearyl Methicone, and Vinyldimethicone are safe as used in cosmetic formulations.

Sensory irritations and pulmonary effects in human volunteers following short-term exposure to pinewood emissions

2011 ◽  
Vol 57 (5) ◽  
pp. 436-445 ◽  
Author(s):  
Richard Gminski ◽  
Rainer Marutzky ◽  
Sebastian Kevekordes ◽  
Frank Fuhrmann ◽  
Werner Bürger ◽  
...  
Keyword(s):  
Short Term ◽  
Short Term Exposure ◽  
Human Volunteers

Effects of marihuana on reaction time and short-term memory in human volunteers

1977 ◽  
Vol 6 (1) ◽  
pp. 73-77 ◽  
Author(s):  
A.Michael Rossi ◽  
John C. Kuehnle ◽  
Jack H. Mendelson
Keyword(s):  
Reaction Time ◽  
Short Term Memory ◽  
Short Term ◽  
Term Memory ◽  
Human Volunteers

scholarly journals Transmission of Methicillin-Resistant Staphylococcus aureus to Human Volunteers Visiting a Swine Farm

2017 ◽  
Vol 83 (23) ◽  
Author(s):  
Øystein Angen ◽  
Louise Feld ◽  
Jesper Larsen ◽  
Klaus Rostgaard ◽  
Robert Skov ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Personal Exposure ◽  
Physical Contact ◽  
Swine Farm ◽  
Short Term ◽  
Methicillin Resistant ◽  
Content Type ◽  
Farm Work ◽  
Short Term Exposure ◽  
Human Volunteers

ABSTRACT Transmission of methicillin-resistant Staphylococcus aureus (MRSA) from animals to humans is of great concern due to the implications for human health and the health care system. The objective was to investigate the frequency and duration of MRSA carriage in human volunteers after a short-term exposure in a swine farm. The experimental study included 34 human volunteers staying 1 h in a MRSA-positive swine farm in four trials. In two of the trials, the influence of farm work involving pig contact was studied using a crossover design. The quantities of MRSA in nasal swabs, throat swabs, and air samples were measured at different time points and analyzed in relation to relevant covariates. This investigation showed that, overall, 94% of the volunteers acquired MRSA during the farm visit. Two hours after the volunteers left the stable, the nasal MRSA count had declined to unquantifiable levels in 95% of the samples. After 48 h, 94% of the volunteers were MRSA-negative. Nasal MRSA carriage was positively correlated to personal exposure to airborne MRSA and farm work involving pig contact and negatively correlated to smoking. No association was observed between MRSA carriage and face touching behavior, nasal methicillin-susceptible Staphylococcus aureus (MSSA) carriage, age, or gender. The increase in human MRSA carriage among the volunteers with pig contact seems to be dependent on the increased concentration of airborne MRSA of the surrounding air and not directly on physical contact with pigs. MRSA was not detected in any of the throat samples. IMPORTANCE The experimental approach made it possible to elucidate the contributions of airborne MRSA levels and farm work to nasal MRSA carriage in a swine farm. Short-term exposure to airborne MRSA poses a substantial risk for farm visitors to become nasal carriers, but the carriage is typically cleared within hours to a few days. The risk for short-term visitors to cause secondary transmissions of MRSA is most likely negligible due to the observed decline to unquantifiable levels in 95% of the nasal samples after only 2 h. The MRSA load in the nose was highly correlated to the amount of MRSA in the air and interventions to reduce the level of airborne MRSA or the use of face masks might consequently reduce nasal contamination.

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