Interindividual variation in the levels of certain urinary polycyclic aromatic hydrocarbon metabolites following medicinal exposure to coal tar ointment

Determination of human exposure to polycyclic aromatic hydrocarbons PAHs is challenging because they are so broadly distributed in the environment and often difficult to quantitate using questionnaire methods. To enhance the ability to non invasively evaluate markers of both internal dose and biologically effective dose we have developed methods for the identification and quantitation of 1 hydroxypyrene-glucuronide and r 7, t 8, t 9, c 10 tetrahydroxy 7,8,9,10 tetrahydrobenzo a pyrene BP 7,10 8,9 tetrol in human urine. In the current study we applied these assays to urine samples collected from 43 hospitalized psoriasis patients treated with coal tar medication and 39 non treated volunteer controls. BP 7,10 8,9 tetrol was detected in 20 of 43 47 patients, ranging from 1 not detected to 124 fmol mumol-1 creatinine. In contrast, BP 7,10 8,9 tetrol was detected in only 4 of 39 10 controls, range 1 to 20.6 fmol mumol-1 creatinine p = 0.0006, Wilcoxon rank sum test . A second, more polar PAH metabolite, identified as 1 hydroxypyrene-glucuronide, was present in all urine samples. Mean 1 hydroxypyreneglucuronide levels were 40.96 72.62 pmol mumol-1 creatinine in patients and 0.38 0.32 pmol mumol-1 creatinine in control subjects p 0.0001 . The ratio of urinary levels of BP 7,10 8,9 tetrol to 1 hydroxypyrene-glucuronide was examined in the coal tar treated patients. This ratio was found to vary by approximately 6000 fold. This parameter cannot be explained by measurement error because the coefficients of variation for these assays are only 12 and 10 respectively, nor can it be explained by use of different coal tar products. These results provide further evidence that substantial interindividual variation in activation of benzo a pyrene and other PAHs exists, which may have implications for disease risk.     

Subsurface near‐infrared laser stimulation of the periprostatic cavernous nerves

Successful identification and preservation of the cavernous nerves (CN), which are responsible for sexual function and vulnerable to damage during prostate cancer surgery, will require subsurface detection of the CN's beneath a thin fascia layer. This study explores the feasibility of optical nerve stimulation (ONS) in the rat with a fascia layer placed over the CN. Two near‐infrared diode lasers with wavelengths of 1455 and 1550 nm were operated in continuous‐wave mode for stimulation of the CN in 8 rats, in vivo. Successful ONS was confirmed by an intracavernous pressure (ICP) response in the rat penis at 1455 nm through fascia with a thickness up to 110 μm and at 1550 nm through fascia with a thickness up to 450 μm. Higher incident laser power was required to produce an ICP response as fascia thickness was increased. Also, weaker and slower ICP responses were observed as fascia thickness was increased. Subsurface ONS of the rat CN at a depth of 450 μm using a 1550 nm laser is feasible as an intermediate step towards developing ONS as an intra‐operative diagnostic tool for identification and preservation of the cavernous nerves during prostate cancer surgery. (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

Global malnutrition overlaps with pollinator-dependent micronutrient production

Pollinators contribute around 10% of the economic value of crop production globally, but the contribution of these pollinators to human nutrition is potentially much higher. Crops vary in the degree to which they benefit from pollinators, and many of the most pollinator-dependent crops are also among the richest in micronutrients essential to human health. This study examines regional differences in the pollinator dependence of crop micronutrient content and reveals overlaps between this dependency and the severity of micronutrient deficiency in people around the world. As much as 50% of the production of plant-derived sources of vitamin A requires pollination throughout much of Southeast Asia, whereas other essential micronutrients such as iron and folate have lower dependencies, scattered throughout Africa, Asia and Central America. Micronutrient deficiencies are three times as likely to occur in areas of highest pollination dependence for vitamin A and iron, suggesting that disruptions in pollination could have serious implications for the accessibility of micronutrients for public health. These regions of high nutritional vulnerability are understudied in the pollination literature, and should be priority areas for research related to ecosystem services and human well-being.     

Human malformations similar to those in the mouse mutation disorganization (Ds)

We report two patients with malformations similar to those seen in mice with the disorganization (Ds) mutation. The first case has a body wall defect, limb malformation, and hamartoma, while the second case has a partially duplicated foot, in addition to the other anomalies. We discuss the implications that recent advances regarding the genetic analysis of the mouse Ds locus have for the search for the human homologue.     

Histone crotonylation promotes mesoendodermal commitment of human embryonic stem cells

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Three-Dimensionally Printed Microfluidic Cross-flow System for Ultrafiltration/Nanofiltration Membrane Performance Testing

Minimization and management of membrane fouling is a formidable challenge in diverse industrial processes and other practices that utilize membrane technology. Understanding the fouling process could lead to optimization and higher efficiency of membrane based filtration. Here we show the design and fabrication of an automated three-dimensionally (3-D) printed microfluidic cross-flow filtration system that can test up to 4 membranes in parallel. The microfluidic cells were printed using multi-material photopolymer 3-D printing technology, which used a transparent hard polymer for the microfluidic cell body and incorporated a thin rubber-like polymer layer, which prevents leakages during operation. The performance of ultrafiltration (UF), and nanofiltration (NF) membranes were tested and membrane fouling could be observed with a model foulant bovine serum albumin (BSA). Feed solutions containing BSA showed flux decline of the membrane. This protocol may be extended to measure fouling or biofouling with many other organic, inorganic or microbial containing solutions. The microfluidic design is especially advantageous for testing materials that are costly or only available in small quantities, for example polysaccharides, proteins, or lipids due to the small surface area of the membrane being tested. This modular system may also be easily expanded for high throughput testing of membranes.