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The start-up of microbial fuel cells (MFCs) requires biofilm development onto electrodes and acclimation of the microbial community to specific substrates. This process is time-consuming and shows low effectivity when complex substrates are utilized. The varying proportions and complex mixtures of volatile fatty acids (VFAs) in bioprocess effluents makes it difficult to predict the power output of VFA-based MFCs when this technology is coupled to a previous bioprocess. In this work, the effect of the degree of reduction of single VFAs on MFC potential was investigated, and a novel acclimation procedure involving the feeding of gradually more complex VFA mixtures is proposed. The power output obtained with butyric acid (6.1 ± 2 mW m−2) was higher than that obtained with propionic acid (5.0 ± 1 mW m−2), as expected based on their degree of reduction. The MFC potential generated by an acetic acid-fed MFC reached 60 mV, but an acetic-butyric acid mixture reduced the cell potential by one order of magnitude. The subsequent addition of propionic acid to the acetic-butyric mixture increased the MFC potential from 1.9 ± 0.1 mV to 35 ± 10 mV in sequential feeding cycles. Consequently, the feeding sequence of acetic, acetic-butyric, and acetic-butyric-propionic acids is proposed as an efficient strategy for the acclimation of MFCs to complex substrates.

Accumulation of bile acids can lead to invalidating pruritus in cholestatic patients. Few reports exist on the influence of lipoprotein-apheresis (LA) on plasma level of total bile acids (tBA). We report of significant decrease in tBA levels and drastic improvement of pruritus in a 5-year-old girl with arthrogryposis-renal failure-cholestasis syndrome. We present LA as a suitable rescue treatment option in therapy-refractory cholestasis-associated pruritus, at least as bridge until a long-term solution such as entero-biliary anastomosis or transplantation is possible.

Fragile X syndrome is the most common cause of inherited mental retardation; it is caused by expansion of CGG repeats in the first exon of the FMR1 gene. The number of CGG repeats varies between 6 and 50 triplets in normal individuals; the most common alleles have 29 or 30 repeats. Allelic patterns in the global populations are similar; however; some reports show statistical differences among several populations. In Mexico, except by a single report on a western Mestizo population, the allelic frequencies of the FMR1 gene are unknown. In this study, we analyze 207, 140, 138, and 40 chromosomes from Mestizos, Tarahumaras, Huichols, and Purepechas respectively. After PCR amplification on DNA modified by sodium bisulfite treatment, molecular analysis of the FMR1 gene showed 30 different alleles among the 525 chromosomes evaluated. Trinucleotide repeat number in the different Mexican populations varied from 15 to 87, with modal numbers of 32 and 30 in Mestizos and Tarahumaras, 29 and 32 in Purepechas and 30 among Huichols. Together, these allelic patterns differ significantly from those reported for Caucasian, Chinese, African, Indonesian, Brazilian, and Chilean populations. The increased number of the unusual allele of 32 repeats observed in the Mexican mestizo population can be explained from its frequency in at least two Mexican native populations. Am. J. Hum. Biol., 2008. © 2008 Wiley-Liss, Inc.

Sporotrichosis in an uncommon mycoses in childhood and is generally associated with injuries received as a consequence of farm work. We undertook a retrospective study of sporotrichosis in children and adolescents seen over a 10-year period, focusing on their clinical, epidemiologic, and mycologic features as well as treatment. We included 25 children with a mean age of 9.3 years. Most of those affected were schoolchildren (84%) from rural areas. The main clinical variety of sporotrichosis seen was the lymphocutaneous form (64%), followed by the fixed cutaneous form (36%), and one instance of the disseminated cutaneous form. Most lesions were located on the upper limbs (40%) and the face (36%). Sporothrix schenckii was isolated in all patients and 24 of 25 had a positive sporotrichin skin test. Nineteen patients were treated and cured clinically and mycologically with potassium iodide, three were cured with itraconazole and one with heat therapy.