ABSTRACT
Objective:To investigate imaging characteristics of papulopustular rosacea (PPR) by high-frequency ultrasound combined with color Doppler flow imaging.Methods:From August 2021 to August 2022, 30 patients with PPR were enrolled from the Department of Dermatology, the First Affiliated Hospital of Baotou Medical College in the Inner Mongolia Autonomous Region, and 30 healthy volunteers served as controls. The 22-MHz high-frequency ultrasound combined with color Doppler blood flow imaging was performed to measure the skin thickness, echo and blood flow parameters at the cheek, and the ultrasound results were compared between the two groups. Comparisons between groups were conducted by using t test or chi-square test. The diagnostic value was analyzed using the area under the curve (AUC) in the receiver operating characteristic (ROC) curve. Results:In the case group, there were 12 males and 18 females, and their ages ranged from 22 to 65 years (42.3 ± 12.8 years) ; in the control group, there were 10 males and 20 females, and their ages ranged from 24 to 62 years (41.0 ± 8.4 years) . The epidermal and dermal thicknesses at the cheek were significantly higher in the case group (132.64 ± 12.29 μm, 1 812.29 ± 85.52 μm, respectively) than in the control group (104.34 ± 14.45 μm, 1 671.77 ± 146.55 μm, respectively, both P < 0.05) . High-frequency ultrasound images showed that the case group was mainly characterized by irregular hypoechoic areas in the cheek dermis (80%) , while banded moderately echoic areas were common in the cheek dermis in the control group (90%) ; subepidermal low-echogenic bands and dermal irregular hypoechoic areas were more likely to appear in the case group than in the control group (93.33% vs. 43.33%, 80% vs. 10%, respectively, both P < 0.001) . Compared with the control group, the case group showed a significantly increased proportion of patients with abundant blood flow signals (93.3% vs. 10%, P < 0.05) , and significantly increased blood vessel diameters (1.60 ± 0.42 mm vs. 0.95 ± 0.32 mm, P < 0.05) ; there was no significant difference in peak systolic blood flow velocity and vascular resistance index between the two groups (both P > 0.05) . The AUC of high-frequency ultrasound combined with color Doppler flow imaging quantitative parameters (including epidermal thicknesses, dermal thicknesses, and blood vessel diameters) was 0.989 (95% CI: 0.970 - 1.000) for the diagnosis of PPR, and the sensitivity and specificity were both 96.7%, which were higher than those of single parameter-based diagnostic model. Conclusion:High-frequency ultrasound combined with color Doppler flow imaging can help improve the accuracy of the diagnosis of PPR, by accurately and non-invasively measuring skin thickness and blood flow parameters.
ABSTRACT
Objective:To compare the in vitro susceptibility of fluconazole-resistant Candida albicans strains from superficial and deep infections to 8 antifungal drugs, and to compare drug resistance mutations in these strains. Methods:According to the Clinical and Laboratory Standards Institute (CLSI) protocol M27-A4, 26 deep infection-derived and 33 superficial infection-derived drug-resistant Candida albicans strains were tested for in vitro susceptibility to 8 antifungal drugs (fluconazole, voriconazole, itraconazole, posaconazole, amphotericin B, fluorocytosine, terbinafine, and micafungin) alone or in combination. DNA was extracted from all drug-resistant strains, and mutations in 3 drug resistance genes, including ERG3, ERG11 and FUR1, were detected by PCR. Normally distributed measurement data with homogeneous variance were compared between two groups by using two-independent-sample t test, non-normally distributed measurement data with non-homogeneous variance were compared using Mann-Whitney U test, and enumeration data were compared using chi-square test. Results:The minimum inhibitory concentrations (MICs) of fluconazole, itraconazole, voriconazole, posaconazole and fluorocytosine all significantly differed between the superficial infection group and deep infection group (all P < 0.05) , while there was no significant difference in the MIC of amphotericin B or micafungin between the two groups (both P > 0.05) . The MIC of terbinafine was >64 μg/ml in 96.6% of the above strains, so could not be compared between groups. As combination drug susceptibility testing revealed, the combination of terbinafine with azoles (fluconazole, voriconazole, itraconazole or posaconazole) showed synergistic inhibitory effects against 15 Candida albicans strains (7 strains from deep infections, 8 strains from superficial infections) , with fractional inhibitory concentration (FIC) indices being 0.033 to 0.187; no marked synergistic effect was observed in the combinations between fluorocytosine and azoles, between fluorocytosine and amphotericin B, or between amphotericin B and fluconazole, with the FIC indices being 0.56 to 1.125. The missense mutation V351A in the ERG3 gene was identified in all the 33 (100%) superficial infection-derived strains, as well as in 13 (50%) deep infection-derived strains, and the mutation A353T in the ERG3 gene was identified in 4 (15%) deep infection-derived strains; as for the ERG11 gene, missense mutations identified in the superficial infection-derived strains included I437V (32 strains, 97%) , Y132H (23 strains, 70%) , T123I (16 strains, 48%) , K128T (6 strains, 18%) , D116E (5 strains, 15%) , A114S (4 strains, 12%) , E266D (2 strains, 6%) , G448E (2 strains, 6%) , and G465S (2 strains, 6%) , while missense mutations identified in the deep infection-derived strains included I437V (23 strains, 88%) , E266D (13 strains, 50%) , E260G (5 strains, 19%) , and V488I (4 strains, 15%) ; the missense mutation R101C in the FUR1 gene was identified in 11 (33%) superficial infection-derived strains, but not identified in deep infection-derived strains. Conclusion:The drug susceptibility and drug resistance mutations differed to some extent between superficial infection- and deep infection-derived fluconazole-resistant Candida albicans strains.