Percutaneous Cervical Vertebroplasty in a MultifunctionalImage-Guided Therapy Suite: Hybrid Lateral Approach to C1 andC4 Under CT and Fluoroscopic Guidance

A 76-year-old patient suffering from two painful osteolytic metastases in C1 and C4 underwent percutaneous vertebroplasty by a hybrid technique in a multi-functional image-guided therapy suite (MIGTS). Two trocars were first placed into the respective bodies of C1 and C4 under fluoroscopic computed tomography guidance using a lateral approach. Thereafter, the patient was transferred on a moving table to the digital subtraction angiography unit in the same room for implant injection. Good pain relief was achieved by this minimally invasive procedure without complications. A hybrid approach for vertebroplasty in a MIGTS appears to be safe and feasible and might be indicated in selected cases for difficult accessible lesion

Ultrafast carrier relaxation in GaN, In_(0.05)Ga_(0.95)N and an In_(0.05)Ga_(0.95)/In_(0.15)Ga_(0.85)N Multiple Quantum Well

Room temperature, wavelength non-degenerate ultrafast pump/probe measurements were performed on GaN and InGaN epilayers and an InGaN multiple quantum well structure. Carrier relaxation dynamics were investigated as a function of excitation wavelength and intensity. Spectrally-resolved sub-picosecond relaxation due to carrier redistribution and QW capture was found to depend sensitively on the wavelength of pump excitation. Moreover, for pump intensities above a threshold of 100 microJ/cm2, all samples demonstrated an additional emission feature arising from stimulated emission (SE). SE is evidenced as accelerated relaxation (< 10 ps) in the pump-probe data, fundamentally altering the re-distribution of carriers. Once SE and carrier redistribution is completed, a slower relaxation of up to 1 ns for GaN and InGaN epilayers, and 660 ps for the MQW sample, indicates carrier recombination through spontaneous emission.Comment: submitted to Phys. Rev.

Fire history of Douglas-fir forests in the Morse Creek drainage of Olympic National Park, Washington

In the Morse Creek drainage of the northeastern Olympic Mountains in Washington state, USA, montane forests dominated by Douglas fir (Pseudotsuga menziesii) owe their prominence to a complex fire regime that incorporates high severity stand-replacing fires and low/moderate severity ground fires. The fire history of these forests was quantified using dendrochronological methods to determine the role played by wildfire to favour dominance of Douglas fir rather than late-successional western hemlock (Tsuga heterophylla). Three matrix forest types reflect the influence of past wildfires. The youngest matrix type was 300 yr old. Germination dates and fire release markers were identified on increment cores from 318 Douglas firs, and used to date past fire events. A 600-yr fire history was developed for this 2500-ha area. Periods characterized by many small-scale, low and moderate severity fires were interrupted by 2 high severity, stand-replacing burning periods in 1687-1720 and 1897-1904. Mean fire return intervals (FRI) were calculated for various land units. The most informative size was 200 ha, the approximate mean size of lateral tributaries to Morse Creek. FRI was 21 yr at this spatial scale. For the entire 2500 ha drainage, mean FRI was estimated at 3 yr. Similar to Douglas-fir forests in central Oregon and northern California, small patchy fires were much more common in the eastern Olympics than previously thought. Instead of fire exclusion, a policy that uses management fires to burn many small patches of forest each year would approach the kind of fire regime typical of these forests.Wetzel and Fonda "Fire history of Douglas-fir forests in the Morse Creek drainage of Olympic National Park, Washington." Northwest Science. 2000; 74(4): 263-27

Fire history of Douglas-fir forests in the Morse Creek drainage of Olympic National Park, Washington

In the Morse Creek drainage of the northeastern Olympic Mountains in Washington state, USA, montane forests dominated by Douglas fir (Pseudotsuga menziesii) owe their prominence to a complex fire regime that incorporates high severity stand-replacing fires and low/moderate severity ground fires. The fire history of these forests was quantified using dendrochronological methods to determine the role played by wildfire to favour dominance of Douglas fir rather than late-successional western hemlock (Tsuga heterophylla). Three matrix forest types reflect the influence of past wildfires. The youngest matrix type was 300 yr old. Germination dates and fire release markers were identified on increment cores from 318 Douglas firs, and used to date past fire events. A 600-yr fire history was developed for this 2500-ha area. Periods characterized by many small-scale, low and moderate severity fires were interrupted by 2 high severity, stand-replacing burning periods in 1687-1720 and 1897-1904. Mean fire return intervals (FRI) were calculated for various land units. The most informative size was 200 ha, the approximate mean size of lateral tributaries to Morse Creek. FRI was 21 yr at this spatial scale. For the entire 2500 ha drainage, mean FRI was estimated at 3 yr. Similar to Douglas-fir forests in central Oregon and northern California, small patchy fires were much more common in the eastern Olympics than previously thought. Instead of fire exclusion, a policy that uses management fires to burn many small patches of forest each year would approach the kind of fire regime typical of these forests

Introduction of an electron withdrawing group on the hydroxyphenylnaphthol scaffold improves the potency of 17&beta;-hydroxysteroid dehydrogenase type 2 (17&beta;-HSD2) inhibitors.

Estrogen deficiency in postmenopausal women or elderly men is often associated with the skeletal disease osteoporosis. The supplementation of estradiol (E2) in osteoporotic patients is known to prevent bone fracture but cannot be administered because of adverse effect. As 17&beta;-hydroxysteroid dehydrogenase type 2 (17&beta;-HSD2) oxidizes E2 to its inactive form estrone (E1) and has been found in osteoblastic cells, it is an attractive target for the treatment of osteoporosis. Twenty-one novel, naphthalene-derived compounds have been synthesized and evaluated for their 17&beta;-HSD2 inhibition and their selectivity toward 17&beta;-HSD1 and the estrogen receptors (ERs) &alpha; and &beta;. Compound 19 turned out to be the most potent and selective inhibitor of 17&beta;-HSD2 in cell-free assays and had a very good cellular activity in MDA-MB-231 cells, expressing naturally 17&beta;-HSD2. It also showed marked inhibition of the E1-formation by the rat and mouse orthologous enzymes and strong inhibition of monkey 17&beta;-HSD2. It is thus an appropriate candidate to be further evaluated in a disease-oriented model

17&beta;-Hydroxysteroid dehydrogenases (17&beta;-HSDs) as therapeutic targets: Protein structures, functions, and recent progress in inhibitor development.

17&beta;-Hydroxysteroid dehydrogenases (17&beta;-HSDs) are oxidoreductases, which play a key role in estrogen and androgen steroid metabolism by catalyzing final steps of the steroid biosynthesis. Up to now, 14 different subtypes have been identified in mammals, which catalyze NAD(P)H or NAD(P)(+) dependent reductions/oxidations at the 17-position of the steroid. Depending on their reductive or oxidative activities, they modulate the intracellular concentration of inactive and active steroids. As the genomic mechanism of steroid action involves binding to a steroid nuclear receptor, 17&beta;-HSDs act like pre-receptor molecular switches. 17&beta;-HSDs are thus key enzymes implicated in the different functions of the reproductive tissues in both males and females. The crucial role of estrogens and androgens in the genesis and development of hormone dependent diseases is well recognized. Considering the pivotal role of 17&beta;-HSDs in steroid hormone modulation and their substrate specificity, these proteins are promising therapeutic targets for diseases like breast cancer, endometriosis, osteoporosis, and prostate cancer. The selective inhibition of the concerned enzymes might provide an effective treatment and a good alternative to the existing endocrine therapies. Herein, we give an overview of functional and structural aspects for the different 17&beta;-HSDs. We focus on steroidal and non-steroidal inhibitors recently published for each subtype and report on existing animal models for the different 17&beta;-HSDs and the respective diseases. Article from the Special issue on Targeted Inhibitors