Estradiol regulation of secretory component in the uterus of the rat: evidence for involvement of RNA synthesis

The present studies were undertaken to characterize the response of uterine secretory component (SC) to estradiol. Administration of estradiol for 3 days to ovariectomized rats before incubation of uterine tissues resulted in a marked accumulation of SC in the incubation media. When uteri from ovariectomized rats treated with progesterone or testosterone were incubated, very little SC accumulated in the media, indicating that the estradiol-stimulated increase is hormone-specific. When uteri from rats that received estradiol for 6 days were compared with uteri from 3-day treated rats, SC release during a 24-hr incubation period was the same. This finding indicates that in the presence of prolonged estradiol exposure, SC production continues. The estradiol-induced accumulation of SC in culture is not due to the release of pre-formed uterine SC. When tissue SC levels were measured after 3 days of estradiol treatment, very little tissue SC was found relative to that released into culture media during 24 hr of incubation. The addition of actinomycin D to the incubation media markedly inhibited SC release by uteri from estradiol-treated rats. The release of SC was also inhibited by alpha-amanitin, a known inhibitor of Type II polymerase. These studies demonstrate that estradiol stimulation of SC is markedly reduced by inhibitors of RNA synthesis, and suggest that estradiol regulation of SC is mediated through uterine mRNA synthesis.     

Predictability of baroreflex sensitivity induced by phenylephrine injection via frequency domain indices computed from heart rate and systolic blood pressure signals during deep breathing

Diminished baroreflex sensitivity (BRS) is related to increased risk of sudden cardiac death in myocardial infarction patients and can be used as an indicator for risk level. The BRS is traditionally estimated invasively using vasoactive drugs, such as phenylephrine injection. This method has been widely accepted as a standard in clinical research. Due to its clinical importance, alternative BRS assessment methods have been investigated over the years to eliminate the use of drugs. In this study, the BRS obtained by drug-based (pharmacological) assessment was predicted from a subset of non-pharmacological indices computed from heart rate and systolic pressure signals. In the first phase of a two-phase experimental paradigm, 16 subjects were asked to perform two deep breathings with a 2-min delay in between. In the second phase, the BRS was measured by phenylephrine injection. Indices computed from the first phase describing the spectral and time domain properties of the heart rate and systolic pressure signals were used as predictors to estimate the pharmacological BRS of each subject. In addition to individual spectrum of beat-to-beat interval and systolic blood pressure, indices from cross-spectrum were also computed and evaluated as predictors. A leave one out method was employed to estimate the generalization capacity of the system and explore subset of indices, which gives the highest correlation between pharmacological and predicted BRS. Two predictors provided the highest correlation (r = 0.87, p = 1.16 × 10⁻⁵) with pharmacological BRS. The algorithm selected consistently normalized cross-power about the Mayer frequency and average magnitude square coherence in the high frequency band as predictors. These results indicate that the pharmacological BRS can be estimated from the combination of non-pharmacological spectral indices computed from beat-to-beat interval and systolic blood pressure signals obtained during deep breathing and therefore may eliminate the use of drugs.     

Buckling of adaptive elastic bone-plate: theoretical and numerical investigation

During day-to-day activities, many bones in the axial and appendicular skeleton are subjected to repetitive, cyclic loading that often results directly in an increased risk of bone fracture. In clinical orthopedics, trabecular fatigue fractures are observed as compressive stress fractures in the proximal femur, vertebrae, calcaneus and tibia, that are often preceded by buckling and bending of microstructural elements (Müller et al. in J Biomechanics 31:150 1998; Gibson in J Biomechanics 18:317-328 1985; Gibson and Ashby in Cellular solids 1997; Lotz et al. in Osteoporos Int 5:252-261 1995; Carter and Hayes in Science 194:1174-1176 1976). However, the relative importance of bone density and architecture in the etiology of these fractures are poorly understood and consequently not investigated from a biomechanical point of view. In the present contribution, an attempt is made to formulate a bone-plate buckling theory using Cowin's concepts of adaptive elasticity (Cowin and Hegedus in J Elast 6:313-325 1976; Hegedus and Cowin J Elast 6:337-352 1976). In particular, the buckling problem of a Kirchhoff-Love bone plate is investigated numerically by using the finite difference method and an iterative solving approach (Chen in Comput Methods Appl Mech Eng 167:91-99 1998; Hildebland in Introduction to numerical analysis 1974; Richtmyer and Morton in Difference methods for initial-value problems 1967).     

Quantifying killing of orangutans and human-orangutan conflict in Kalimantan, Indonesia

Human-orangutan conflict and hunting are thought to pose a serious threat to orangutan existence in Kalimantan, the Indonesian part of Borneo. No data existed prior to the present study to substantiate these threats. We investigated the rates, spatial distribution and causes of conflict and hunting through an interview-based survey in the orangutan's range in Kalimantan, Indonesia. Between April 2008 and September 2009, we interviewed 6983 respondents in 687 villages to obtain socio-economic information, assess knowledge of local wildlife in general and orangutan encounters specifically, and to query respondents about their knowledge on orangutan conflicts and killing, and relevant laws. This survey revealed estimated killing rates of between 750 and 1800 animals killed in the last year, and between 1950 and 3100 animals killed per year on average within the lifetime of the survey respondents. These killing rates are higher than previously thought and are high enough to pose a serious threat to the continued existence of orangutans in Kalimantan. Importantly, the study contributes to our understanding of the spatial variation in threats, and the underlying causes of those threats, which can be used to facilitate the development of targeted conservation management.     

Enantioselective desymmetrization of meso-epoxides with anilines catalyzed by polymeric and monomeric Ti(IV) salen complexes

The active catalysts for the enantioselective ring opening (ARO) of meso-stilbene oxide, cis-butene oxide, cyclohexene oxide, cyclopentene oxide, and cyclooctene oxide with various substituted anilines were generated in situ by the reaction of Ti(O(i)Pr)(4) with poly-[(R,R)-N,N'-bis-{3-(1,1-dimethylethyl)-5-methylene salicylidene} cyclohexane-1,2-diamine]-1 and (1R,2R)-N,N'-bis[3,5-di(tert-butyl)salicylidene] cyclohexane-1,2-diamine-2. These catalysts in the presence of nonracemic imine as an additive provided β-amino alcohol in excellent yield (99%) and chiral purity (enantiomeric excess (ee) up to 99%) for the ARO of meso-stilbene oxide with aniline. The same protocol was less effective for the ARO of cyclic epoxides; however, when triphenylphosphine was used as an additive, there was a significant improvement in catalyst performance for the ARO of cyclohexene oxide (yield, 85-90%; ee, 63-67%). Both in situ generated polymeric and monomeric catalysts performed in a similar manner except that the polymeric catalyst Ti(IV)-1 was more active and recycled several times with retention of enantioselectivity when compared with the monomeric catalyst Ti(IV)-2, which was nonrecyclable.     

Surface plasmon resonance sensing detection of mercury and lead ions based on conducting polymer composite

A new sensing area for a sensor based on surface plasmon resonance (SPR) was fabricated to detect trace amounts of mercury and lead ions. The gold surface used for SPR measurements were modified with polypyrrole-chitosan (PPy-CHI) conducting polymer composite. The polymer layer was deposited on the gold surface by electrodeposition. This optical sensor was used for monitoring toxic metal ions with and without sensitivity enhancement by chitosan in water samples. The higher amounts of resonance angle unit (ΔRU) were obtained for PPy-CHI film due to a specific binding of chitosan with Pb(2+) and Hg(2+) ions. The Pb(2+) ion bind to the polymer films most strongly, and the sensor was more sensitive to Pb(2+) compared to Hg(2+). The concentrations of ions in the parts per million range produced the changes in the SPR angle minimum in the region of 0.03 to 0.07. Data analysis was done by Matlab software using Fresnel formula for multilayer system.