Citations

ABSTRACT A 45-year-old man from Nepal with a 13-year history of polycystic kidney disease was diagnosed as suffering from chronic renal failure with end-stage renal disease. After receiving empirical antituberculosis treatment, he was treated with broad-spectrum antibiotics. A left nephrectomy was performed, and after 4 months, he received a kidney transplant. The left kidney was grossly enlarged, with multiple cystic spaces filled with blackish material. Histologic examination of the excised left kidney tissue stained with hematoxylin and eosin and Gomori's methenamine silver stains showed numerous hyaline, septate, fungal hyphae of various lengths, many broken into rectangular arthroconidia in the cystic spaces. Culture of the kidney tissue yielded white, glabrous, yeast-like colonies. Based on its micromorphology, growth at 42°C, and ribosomal DNA (rDNA) sequence analysis, and also sequence analysis of the internal-transcribed-spacer and D1/D2 rDNA regions, the yeast was identified as Trichosporon loubieri. Postsurgically, the patient was treated with amphotericin B and oral itraconazole, followed by maintenance therapy with fluconazole. He remained afebrile and asymptomatic. At the final follow-up, all parameters were found normal and the patient was doing well, with normal renal function reports. This paper presents the first known case of human infection caused by T. loubieri.

ABSTRACT We compared the performance characteristics of a real-time PCR method, the LightCycler Strep-A assay (Roche Applied Science, Indianapolis, Ind.), to those of a rapid antigen immunoassay, the Directigen 1-2-3 Group A Strep Test kit (BD Diagnostic Systems, Sparks, Md.), and a standard culture method for detection of group A streptococci (GAS) from 384 throat swabs. The LightCycler PCR produced more positive results ( n = 58) than either culture ( n = 55) or the Directigen immunoassay ( n = 31). The results of the LightCycler PCR and the Directigen method were independently compared to the results of the accepted “gold standard,” bacterial culture. The sensitivities, specificities, and positive and negative predictive values for this comparison were as follows: for the Directigen method, 55, 99, 97, and 93%, respectively; for the LightCycler PCR, 93, 98, 88, and 99%, respectively. In no case was a throat swab positive by both the LightCycler PCR and the Directigen method but negative by culture. The medical histories of patients whose throat swabs were negative by culture but positive by either the LightCycler PCR ( n = 7) or the Directigen method ( n = 1) were reviewed. All of these patients had signs or symptoms compatible with GAS disease, and therefore, all of these discordant positive results (along with positive results by either the Directigen method or the LightCycler PCR that agreed with the culture results) were counted as true positives for statistical analysis. For this analysis, the LightCycler PCR detected more true-positive results than the culture method (58 versus 55 swabs); however, this difference was not statistically significant ( P = 0.5465). In contrast, statistically significantly more true-positive results occurred by culture than by the Directigen method (55 versus 31 swabs; P < 0.0001) and by the LightCycler PCR than by the Directigen method (58 versus 31 swabs; P < 0.0001). The LightCycler PCR is a suitable stand-alone method for the detection of GAS from throat swabs. Additionally, this method requires less than half the personnel time and the procedure can be completed in considerably less time (∼1 h) than our standard approach (up to 2 days) for detection of GAS in throat swabs (i.e., testing by the Directigen method with negative results verified by culture).

There is a current need for a small diameter vascular graft due to the limited supply of autogenous grafts and the failure of synthetic grafts due to thrombosis and/or intimal hyperplasia. The use of living cells and tissues to fabricate a small diameter graft (i.e., tissue engineered blood vessel, TEBV) could be useful given the endothelialization potential and biocompatibility benefits of such a graft. However, while sufficient strength has been attained in a TEBV, coordinate compliance has yet to be fine-tuned. In this study we investigate the effects of biological response modifiers, retinoic acid (RA) and ascorbic acid (AA) on TEBV biomechanics as a function of time and subsequently correlate observed RA/AA induced changes in TEBV mechanics with alterations in smooth muscle cell (SMC) biochemistry. TEBVs were constructed using a fibrillar type I collagen network populated by human aortic smooth muscle cells (AoSMC). Following construction this TEBV was treated with 0.3 mM AA and 0.1 mM RA (concentrations found to induce changes in VSMC phenotype). Ultimate tensile stress (UTS), rate of relaxation (RR) and elastic efficiency (EE) of RA/AA treated and untreated TEBVs were measured following 1, 7, 15, 30, 45, and 60 days of treatment. At corresponding time points, the effect of these treatments on collagen and elastin protein synthesis and mRNA expression was examined. RA/AA treated TEBV strength increased and stiffness decreased compared to controls as a function of time. Relative collagen synthesis in treated TEBVs exceeded control levels by nearly two-fold at 15 and 30 days of incubation. RA/AA treated collagen gene expression followed a similar trend. Relative elastin synthesis was also greater in treated TEBVs as compared to untreated TEBVs at 15 and 30 days of incubation and correspondingly elastin mRNA expression was significantly elevated at 15 days of incubation. These data provide evidence that RA/AA treated TEBVs exhibit mechanical properties which more closely mimic those of a native vessel than their untreated counterparts and that changes in extracellular matrix composition and matrix gene expression in the presence of RA/AA treatment may play an important role in the development of said mechanical properties.