Development of a cumulative irritation model for incontinence-associated dermatitis.

Incontinence-associated dermatitis (IAD) is a painful yet preventable form of cumulative skin irritation prevalent amongst those with limited movement. Consequently, it has a significant impact on the quality of life for those affected as well as substantial cost implications. Prevention and intervention is typically through good skin hygiene regimes and regular use of barrier products. In this paper, we describe the development of an in vivo model of IAD in healthy volunteers by occluded application of alkaline synthetic urine to the volar aspect of volunteer's forearms for 6 h per day over a five-day period to reproduce the moist and irritant conditions causative of IAD. Irritation was assessed and quantified on a daily basis by a series of non-invasive biophysical measurements and compared to a contralateral saline-treated (control) site. Dermal irritation was assessed by subjective (visual) and objective measurements (laser Doppler and polarisation spectroscopic imaging, infrared thermography, skin reflectance spectroscopy, transepidermal water loss and skin surface pH). The provocation of reproducible, cumulative skin irritation was successfully demonstrated and quantified. This five-day model of irritation is considered appropriate for the initial clinical assessment of topical products to prevent or treat IAD.

Limb lengthening in children with Russell-Silver syndrome: a comparison to other etiologies.

INTRODUCTION/BACKGROUND: Russell-Silver syndrome (RSS) is the combination of intrauterine growth retardation, difficulty feeding, and postnatal growth retardation. Leg length discrepancy (LLD) is one of four major diagnostic criteria of RSS and is present in most cases. We aimed to ascertain whether pediatric RSS patients will adequately consolidate bony regenerate following leg lengthening. MATERIALS AND METHODS: We retrospectively reviewed pediatric RSS patients who underwent limb lengthening and compared them to a similar group of patients with LLD resulting from tumor, trauma, or congenital etiology. The primary outcome measurement was the bone healing index (BHI). RESULTS: The RSS group included seven lengthened segments in five patients; the comparison group included 21 segments in 19 patients. The groups had similar lengthening amounts (3.3 vs. 3.9 cm, p = 0.507). The RSS group healed significantly faster (lower BHI) than the control group (BHI 29 vs. 43 days/cm, p = 0.028). Secondary analysis showed no difference between RSS and trauma patients in terms of the BHI (29 vs. 31); however, the BHI of the RSS group was significantly lower than both of the other congenital etiologies (29 vs. 41, p = 0.032) and tumor patients (29 vs. 66, p = 0.019). The RSS patients had fewer and less significant complications than the controls. DISCUSSION: The limb lengthening regenerate healing of RSS patients is faster than the healing of patients with other congenital etiologies and tumor patients, and is as fast as the regenerate healing of patients with posttraumatic LLD. Although all RSS patients were treated with human growth hormone (hGH), we are unable to isolate the hGH contribution to the regenerate bone healing. We conclude that RSS patients can have safe limb lengthening.

Engineering prolonged-acting prodrugs employing an albumin-binding probe that undergoes slow hydrolysis at physiological conditions.

Here we describe the design and application of OSu-FMS-MAL-S-(CH(2))(15)-COOH, an agent that associates with albumin while linked to a peptide or a protein with sufficient affinity (Ka=2 to 2.6 x 10(5)M(-1)) to protract the action of short- lived peptides and proteins in vivo. Under physiological conditions this probe undergoes spontaneous hydrolysis with the concomitant reactivation of inactive conjugates. Intravenously administered (125)I-labeled-Insulin-FMS-MAL-S-(CH(2))(15)-COOH to rats shows half-life of 17+/-2h, exceeding 5.2 times that obtained with intravenously administered (125)I-labeled Insulin. In mice this derivative facilitates glucose-lowering effect over a period of 24h, yielding AUC five times greater than that obtained by a similar dose of insulin-detemir. Similarly, subcutaneous administration of Exendin-4-FMS-MAL-S-(CH(2))(15)-COOH into mice facilitated prolonged and stable reduction in glucose level, yielding a t(1/2) value of 28+/-2h, exceeding the effect of exendin-4 4.7 folds. The inactive derivative gentamicin-FMS-MAL-S-(CH(2))(15)-COOH regained its full antibacterial potency upon incubation at physiological conditions yielding a t(1/2) value of 7.1+/-0.2h. In conclusion, the albumin-binding probe we introduced enables to prolong the action of any amino containing molecule in vivo, without the drawback of inactivation that often occurs upon such derivatization.

e/3 Laughlin quasiparticle primary-filling nu=1/3 interferometer.

We report experimental realization of a quasiparticle interferometer where the entire system is in 1/3 primary fractional quantum Hall state. The interferometer consists of chiral edge channels coupled by quantum-coherent tunneling in two constrictions, thus enclosing an Aharonov-Bohm area. We observe magnetic flux and charge periods h/e and e/3, equivalent to the creation of one quasielectron in the island. Quantum theory predicts a 3h/e flux period for charge e/3, integer statistics particles. Thus, the observed periods demonstrate the anyonic braiding statistics of Laughlin quasiparticles.

Aharonov-Bohm superperiod in a Laughlin quasiparticle interferometer.

We report an Aharonov-Bohm superperiod of five magnetic flux quanta (5h/e) observed in a Laughlin quasiparticle interferometer, where an edge channel of the 1/3 fractional quantum Hall fluid encircles an island of the 2/5 fluid. This result does not violate the gauge invariance argument of the Byers-Yang theorem because the magnetic flux, in addition to affecting the Aharonov-Bohm phase of the encircling 1/3 quasiparticles, creates the 2/5 quasiparticles in the island. The superperiod is accordingly understood as imposed by the anyonic statistical interaction of Laughlin quasiparticles.

Whiteflies (Bemisia tabaci) issued from eggs bombarded with infectious DNA clones of Tomato yellow leaf curl virus from Israel (TYLCV) are able to infect tomato plants.

We have reported previously that Tomato yellow leaf curl virus from Israel (TYLCV) penetrates the reproductive system of its vector, the whitefly Bemisia tabaci biotype B, and may be transmitted to progeny. In order to mimic this phenomenon and to understand how TYLCV accompanies the development of the insect, we have bombarded B. tabaci eggs with an infectious DNA clone of TYLCV. After a linear full-length genomic copy of TYLCV DNA was delivered to eggs, the DpnI-sensitive DNA became circular and DpnI resistant. When a dimeric copy of TYLCV DNA was delivered to eggs, the viral DNA was detected in all the whitefly developmental stages. Adult insects that developed from the treated eggs were able to infect tomato test plants with variable frequency. Viral DNA was detected in the progeny of whiteflies that developed from eggs bombarded with TYLCV. Similarly, when insect eggs were bombarded with a dimeric copy of an infectious clone of the genome of Tomato yellow leaf curl virus from Sardinia, Italy (TYLCSV), adults that eclosed from the treated eggs were able to infect tomato test plants.

Absence of compressible edge channel rings in quantum antidots.

We report resonant tunneling experiments in a quantum antidot sample in the integer quantum Hall regime. In particular, we have measured the temperature T dependence of the peak value of a conductance peak on the i = 2 plateau, where there are two peaks per magnetic flux quantum straight phi(0). We observe a T-1 dependence as expected when tunneling through only one electron state is possible. This result is incompatible with tunneling through a compressible ring of several degenerate states. We also observe, for the first time, three conductance peaks per straight phi(0) on the i = 3 plateau.

Effect of beta-glucan from oats and yeast on serum lipids.

Heart disease is the leading cause of death in the U.S. One way to reduce the risk of developing the disease is to lower serum cholesterol levels by making dietary changes. In addition to reducing intake of total fat, saturated fat, and dietary cholesterol, serum cholesterol can be further reduced by added fiber, especially from sources rich in beta-glucan. In this review, two sources of beta-glucan are described; one source is oats and the other yeast. Their chemical structures and physical properties are compared, and their effect on serum lipid levels is described. Oat beta-glucans are found in various breakfast cereals and snacks. Usually, several servings of these products are required to meet the Food and Drug Administration's claim of reducing the risk of heart disease. The yeast-derived fiber is a more concentrated source of beta-glucan than the oat product. It is currently being tested in a wide variety of food products.

Resonant tunneling in the quantum Hall regime: measurement of fractional charge.

In experiments on resonant tunneling through a "quantum antidot" (a potential hill) in the quantum Hall (QH) regime, periodic conductance peaks were observed as a function of both magnetic field and back gate voltage. A combination of the two periods constitutes a measurement of the charge of the tunneling particles and implies that charge deficiency on the antidot is quantized in units of the charge of quasi-particles of the surrounding QH condensate. The experimentally determined value of the electron charge e is 1.57 x 10(-19) coulomb = (0.98 +/- 0.03) e for the states v = 1 and v = 2 of the integer QH effect, and the quasi-particle charge is 5.20 x 10(-20) coulomb = (0.325 +/- 0.01)e for the state v = (1/3) of the fractional QH effect.

Observation of single-electron charging in double-barrier heterostructures.

Incremental single-electron charging of size-quantized states has been observed in the well in submicrometer double-barrier resonant tunneling devices. In order to distinguish between the effects of size quantization and the single-electron charging, the heterostructure material was grown asymmetrical so that one barrier is substantially less transparent than the other. In the voltage polarity such that the emitter barrier is more transparent than the collector barrier, electrons accumulate in the well; incremental electron occupation of the well is accompanied by Coulomb blockade, which leads to sharp steps of the tunneling current. In the opposite voltage polarity the emitter barrier is less transparent than the collector barrier and the tunneling current reflects resonant tunneling through size-quantized well states.