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Objective: With the emergence of the COVID-19 virus, there was a widespread infection rate among college campuses, creating a need to understand the impact of COVID-19 infection on the health and wellbeing of adolescents. The aim of this study was to examine COVID-19 incidence and cardiorespiratory fitness (CRF) among undergraduate students in the 2 years post-COVID-19 pandemic lock-down., Participants: Participants ( n  = 151) included undergraduate college freshmen students during the 2021-2022 and 2022-2023 academic years., Methods: A series of annual surveys ( n  = 151) and laboratory measures among a sub-sample of participants ( n  = 28) were conducted to assess COVID-19 incidence, CRF, anthropometrics, and physical activity (PA)., Results: Over half of participants self-reported COVID-19 infection (59%), "good" or better CRF, a healthy body mass index (BMI), and 25% met PA recommendations. Nearly a quarter, (24%) perceived a negative impact of COVID-19 on their CRF and although not statistically significant, participants who contracted COVID-19 had 46% lower odds of having a positive perception of CRF than those who did not contract COVID-19 before. However, students who were more physically active were more likely to perceive a negative impact of COVID-19 incidence on their CRF ( p  = 0.035)., Conclusion: Although no relationship was detected between COVID-19 and CRF, those who perceived a negative impact of COVID-19 on their CRF reported engaging in more physical activity., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 Alvaro, Levers, Barberio, Jin, Stranieri and Sacheck.)

Abstract: Hatfield, DL, Stranieri, AM, Vincent, LM, and Earp, JE. Effect of a neoprene knee sleeve on performance and muscle activity in men and women during high-intensity, high-volume resistance training. J Strength Cond Res 35(12): 3300-3307, 2021-The purpose of this study was to assess the effects of a commercially available neoprene knee sleeve (KS) on exercise performance and muscle activity during an exhaustive leg press exercise. Twenty resistance-trained individuals, 11 men {21.0 ± 2.2 years; 77.7 ± 8.7 kg; 1 repetition maximum (1RM/body mass [BM]): 0.30 ± 0.04} and 9 women (22.0 ± 3.5 years; 66.1 ± 9.1 kg; 1RM/BM: 0.30 ± 0.04), all subjects (21.5 ± 2.8 years; 72.5 ± 10.5 kg; 1RM/BM: 0.30 ± 0.04), participated in 3 testing sessions. The second and third sessions were performed using a counterbalanced and randomized design in which subjects exercised with (WS) or without (NS) KSs and performed 6 sets of leg press exercise at 80% of 1RM until failure with a 3-minute rest between sets. Number of repetitions, blood lactate (BL), heart rate (HR), rating of perceived exertion (RPE), and peak and average power were recorded after each set. Surface electromyography (EMG) of the right and left vastus lateralis muscles was also recorded to compare muscle activity between conditions. Significance was set at p ≤ 0.05, and values are presented as mean ± SD. No significant differences were observed in the total number of repetitions for all sets (p = 0.3; WS 75.3 ± 33.7, NS 79.8 ± 34.3) and the number of repetitions per set between conditions (p ≤ 0.05) or between men and women. Similarly, no significance differences (p ≤ 0.05) were observed for BL, HR, RPE, or EMG per set between conditions or between men and women. These results suggest that wearing compressive neoprene KSs has no effect on improving performance and associated variables during high-load, high-volume lower-body resistance training., (Copyright © 2021 National Strength and Conditioning Association.)

Sebum production has been measured in twenty patients in whom 13-cis-retinoic acid therapy had been discontinued for at least 20 weeks. While sebum production had returned to pretreatment levels by 30 weeks in seven subjects, 30% to 80% reduction in sebaceous gland activity was still present for as long as 80 weeks in eight subjects. Four of these eight patients, who were followed for more than a year, still had marked sebaceous inhibition when last tested. The prolonged remission seen in patients with nodulocystic acne may be related in part to continued sebaceous gland inhibition in some patients, but it obviously is not the only actor responsible for the long-term improvement that is seen.

1,2,3,4-Tetrahydro-1,1,4,4-tetramethyl-y-[(E)-alpha-methylstyryl]- naphthalene (Ro 15-0778), a potent inhibitor of sebaceous gland activity in several animal models has been administered to male volunteers in dosages of 1, 2, 3, and 6 mg/kg/day and 2 g/day for 8 weeks. Sebum production was measured before treatment and after 4 and 8 weeks of therapy. At the dosage levels of 1, 2, 3, and 6 mg/kg/day there was no decrease in sebum secretion. With the dosage of 2 g/day, a significant decrease in sebum secretion was seen after 8 weeks of treatment with Ro 15-0778.

When sebum is collected from the skin surface in an absorbent material, the amounts obtained in successive collections at the same site decline steadily. In the present study, sebum was absorbed into bentonite clay applied to 2.5 sq cm areas on the foreheads of 3 subjects for 3-hr intervals during 24 hr. The amounts of sebum obtained, measured by thin-layer chromatography, declined for 12 hr and then remained constant for the remaining 12 hr. It was inferred that the final, sustainable rate represents the true rate at which sebum was being secreted by the sebaceous glands, and that the additional sebum collected at earlier intervals was obtained from an accumulation in the stratum corneum or in the follicular canals. For the 3 subjects, the accumulated sebum averaged 213 micrograms/sq cm, compared with a sustainable secretion rate of 25 micrograms/sq cm/hr. The large quantity of accumulated sebum, relative to the secretion rate, could obscure differences between subjects when sebum secretion rates are measured by short-term collections of sebum in absorbent materials.

Changes in sustainable rates of sebum secretion were followed in twenty patients with severe acne who were receiving oral treatment with 13-cis-retinoic acid in dosages of 0.1, 0.5, or 1.0 mg/kg/day. Sebum secretion was measured by absorption of skin surface lipid into bentonite clay and estimation of the amount of absorbed sebum by measurement of its wax ester component. Pretreatment rates of sebum secretion in the patients were greatly elevated in comparison with previously measured values in young adult subjects without acne. After 4 weeks of treatment, mean rates of sebum secretion on all three dose levels fell to or below the range for normal subjects. On-treatment rates of sebum secretion were significantly lower in patients on the highest dose compared to patients on the lowest dose. When the drug was discontinued, rates of sebum secretion recovered slowly. Clinical response was excellent in most of the subjects. The five subjects with least favorable response clinically all had better than average suppression of sebum production.

Fourteen patients with severe, treatment-resistant, nodulocystic acne have been treated with 13-cis-retinoic acid in a double-blind study. The patients were treated with either 0.1, 0.5, or 1.0 mg/kg/day of 13-cis-retinoic acid for 12 weeks. A marked dose-related decrease in sebum production, which was usually evident within 2 weeks of the onset of therapy, was observed in all patients. At a dose of 1.0 mg/kg/day of 13-cis-retinoic acid, sebum production was decreased to about 10% of the pretreatment value. Clinical improvement, as judged by counting the nodulocystic lesions and measuring their greatest diameters, was noted in all three groups. The most common clinical side effects were cheilitis, desquamation of the skin, and pruritus, but the side effects were not severe enough to require interruption of treatment. Laboratory abnormalities during therapy were minimal and also did not necessitate the cessation of therapy.

Sebum production and skin surface lipid composition have been measured during the oral treatment with 13cis-retinoic acid of a group of patients with severe cystic acne. Two hundred and thirty-eight paired samples have been analyzed and compared. A marked, drug-induced decrease in sebum production was accompanied by a decrease in the concentration of wax esters, a slight decrease in the squalene concentration and in increase in the cholesterol concentration in the skin surface lipids. These changes were consonant with changes in the relative contributions of sebum and epidermal lipid to the surface film, except that at very low levels of sebum production there might be preferential preservation of squalene synthesis.

A double-blind investigation has been conducted to examine the effect of topical 4% erythromycin/1.2% zinc acetate solution and its vehicle on quantitative bacterial counts (skin surface washings) of propionibacterium acnes and the free fatty acids of the skin surface. The logarithmic counts for P. acnes in the erythromycin/zinc group showed a significant reduction (98%) following 10 weeks of therapy. This compared with a 43% change shown for the vehicle-control group. A significant reduction (69%) in the percentage of free fatty acids in the surface lipids was seen at week 4 in the erythromycin/zinc group as compared to the control group. Triglyceride levels were significantly increased at all time points for the erythromycin/zinc group as compared to the control group. There was also a significant decrease (69%) in inflammatory lesions shown for the erythromycin/zinc treatment group at week 8 as compared to a 9% reduction in the control group.