Asymmetric cell convergence-driven zebrafish fin bud initiation and pre-pattern requires Tbx5a control of a mesenchymal Fgf signal.

Tbx5 plays a pivotal role in vertebrate forelimb initiation, and loss-of-function experiments result in deformed or absent forelimbs in all taxa studied to date. Combining single-cell fate mapping and three-dimensional cell tracking in the zebrafish, we describe a Tbx5a-dependent cell convergence pattern that is both asymmetric and topological within the fin-field lateral plate mesoderm during early fin bud initiation. We further demonstrate that a mesodermal Fgf24 convergence cue controlled by Tbx5a underlies this asymmetric convergent motility.

Mutation in Osteoactivin Promotes Receptor Activator of NFκB Ligand (RANKL)-mediated Osteoclast Differentiation and Survival but Inhibits Osteoclast Function.

We previously reported on the importance of osteoactivin (OA/Gpnmb) in osteogenesis. In this study, we examined the role of OA in osteoclastogenesis, using mice with a nonsense mutation in the Gpnmb gene (D2J) and wild-type controls (D2J/Gpnmb(+)). In these D2J mice, micro-computed tomography and histomorphometric analyses revealed increased cortical thickness, whereas total porosity and eroded surface were significantly reduced in D2J mice compared with wild-type controls, and these results were corroborated by lower serum levels of CTX-1.

Placental development and expression of calcium transporting proteins in the extraembryonic membranes of a placentotrophic lizard.

Pseudemoia pagenstecheri is a viviparous Australian scincid lizard in which the maternal-embryonic placental interface is differentiated into structurally distinct regions. The chorioallantoic placenta contains an elliptical-shaped region, the placentome, characterized by hypertrophied uterine and embryonic epithelial cells supported by dense vascular networks. The remainder of the chorioallantoic placenta, the paraplacentome, is also highly vascularized but uterine and chorionic epithelia are thin.

Structure-activity relationship and docking studies of thiazolidinedione-type compounds with monoamine oxidase B.

The neuroprotective activity of pioglitazone and rosiglitazone in the MPTP parkinsonian mouse prompted us to evaluate a set of thiazolidinedione (TZD) type compounds for monoamine oxidase A and B inhibition activity. These compounds were able to inhibit MAO-B over several log units of magnitude (82 nM to 600 μM). Initial structure-activity relationship studies identified key areas to modify the aromatic substituted TZD compounds.

Preferences for body type and body characteristics associated with attractive and unattractive bodies: Jackson and McGill revisited.

The present investigation replicates Jackson and McGill's study (1996) and extends it by considering the effects of respondents' own height, weight, and body mass on perceptions of attractiveness. Results, although generally supportive of those found by Jackson and McGill, point to the influence of respondents' own physical characteristics in the process of perceptions of attractiveness: only 1 of Jackson and McGill's 3 (of a possible 19) differences between responses of African- and Euro-American women was corroborated (the importance of silky hair for Euro-American women), whereas a second difference (the importance of round buttocks for African-American women) disappeared when controlling for respondents' weight, height, and body mass. Although differences between the two investigations may be attributed to regional differences in the surveyed students (Michigan and North Carolina), the small effect of one's own weight, height, and body mass in assessing an other-sex person's attractiveness may reflect adherence to norms learned very early in life that are subject to regional variations.

Cardiovascular measurements relevant to heart size in copper-deficient rats.

Dietary copper deficiency in animals is often associated with cardiac enlargement and anemia. In this study we examined the hypothesis that anemia leads to a high cardiac output state that results in work-induced (physiological) cardiac hypertrophy. Blood pressure was measured by carotid cannulation and cardiac output was measured by aortic flow probe in anesthetized, open-chested rats that had been subjected to various degrees of dietary copper deficiency for five weeks.

Comparison of rat aortic, carotid & femoral artery viscoelastic properties using harmonic analysis.

Viscoelastic properties of rat (Wistar Kyota) large (6 aorta), medium (12 carotid) and small (8 femoral) in vitro artery segments, were contrasted over a wide range of static and dynamic pressures. Relationship of change in static pressure (delta dyne/mm2) to diameter (delta mm) was used to estimate a segment's incremental elasticity (KD) at each pressure level. Dynamic intravascular pressure response (Po) was recorded during swept frequency pressure (2-200 Hz; +/- 10 mm Hg) inputs as superimposed on mean pressure steps of 40, 80, 120, 160 and 200 mm Hg (P(i)).

The mobility analog for modeling the intra-arterial pressure wave parameters.

To assist in the identification of physical/physiological parameters obtained from in vivo rat aortic artery dynamic pressure data, the natural (mobility) mechanical circuit model was constructed. The direct electrical analog of the model thus obtained was then analyzed using SPICE. The experimental data were obtained using a Multifunction Pressure Generator (MPG), appropriate pressure probes, and a high-speed video camera.

Transfer function comparisons of rat aortic wall image and intravascular pressure harmonic responses.

This study examined the relationship between rat (mature Sprague-Dawley males) thoracic aortic wall and intraluminal pressure responses to a dynamic pressure input. High speed video image (Do) of outer wall area and intravascular pressure (Po) responses of the in vitro aorta were digitized and computer recorded during swept frequency pressure input (2-200 Hz; +/- 10 mm Hg) that was superimposed on static pressures from 20 to 200 mm Hg (Pi). Analysis included Fast Fourier transform (FFT) for Do/Pi and Po/Pi transfer functions and focused on comparison of coefficients from FANSIM (TUTSIM Products) polynomial equation fit to Bode plots for mean data of multiple aortas.

Synchronizing blood vessel response CCD imagery to swept frequency dynamic pressure signals.

Harmonic analysis of the pressure and wall responses of a blood vessel exposed to a dynamic pressure input signal required the development of a software application which could properly synchronize the data gathered by two separate microcomputers. In order to accomplish this task, the Pressure-Image Editor was developed. The first computer is used to generate a swept frequency sinusoidal dynamic pressure input signal while at the same time monitoring the resulting response pressures.

Harmonic analysis of intravascular pressure response as an index of arterial wall mechanical properties.

The ability to routinely assess mechanical properties of large blood vessels, like the aorta, before an aneurysm or rupture occurs, could benefit diagnostic and therapeutic procedures and save lives. In this study, images of the wall area and intravascular pressure (IP) responses of in vitro rat aorta were recorded during swept frequency pressure input (2-200 Hz; +/- 10 mm Hg) superimposed on mean pressures from 20 to 160 mm Hg. Data analysis included Fast Fourier transform (FFT) of input and responses.

Intra-arterial pressure wave parameters modeled using electrical analogs.

An Electrical Model was developed to help identify parameters obtained from dynamic pressure data on the in vitro rat aortic artery. The data was obtained using a Multifunction Pressure Generator (MPG) and recording MPG Input Pressure (Pi) and Intraarterial Pressure (Po). Transfer functions of the form Po/Pi = (A1S+Ao)/(B2S2 + B1S+Bo) were obtained and it is necessary to link A1, Ao, B2, B1 and Bo to the Biological Parameters of Inertance (M), Vascular Resistance (R) and Compliance (C).

Arterial elastic modulus for fixed and varied wall volume.

It is commonly assumed that a blood vessel maintains a constant wall volume over a wide range of intraluminal pressures. We have found that vessel wall volume decreases under increasing load. To determine the effect of decreasing wall volume on values of Elastic modulus (Em), two computer models were used.

Dynamic intra-vascular pressure harmonic analysis.

The postulate that dynamic intra vascular pressure is a function of positional wall properties has been difficult to verify due to non-linear viscoelastic influences in arteries. It was tested, in rabbit carotid artery in vitro segments using dynamic and static input. A Multifunction Pressure Generator (MPG, Millar Inc.

Viscoelastic influence on wall and baroreceptors of rabbit carotid sinus.

This study examined multifiber baroreceptor nerve activity (BNA) as a function of carotid sinus wall distension in 19 rabbits. Analysis estimated mechanical or viscoelastic properties of the sinus wall and their influence on BNA. In six sinuses, properties were altered by treatment with the enzyme protease to remove the endothelium and with nifedipine to passively relax smooth muscle.

Endothelial vasoactive influence simulated by exponential feedback.

We hypothesized that results from rabbit carotid sinus wall and baroreceptors could be simulated using exponential feedback in a viscoelastic model. Wall and baroreceptor were each modeled by second order differential equations. Coefficients for viscosity, elasticity and feedback were estimated from experimental data.

Virtual instrumentation for frequency analysis of carotid sinus responses.

An advanced microcomputer based process control and instrumentation system was developed for real time frequency analysis of the viscoelastic relationships between the carotid sinus wall and indwelling baroreceptors. A 486 based AT bus microprocessor running data acquisition and visualization software was customized providing a virtual instrument for data collection, display, and recording. A full complement of signal processing algorithms was developed for the collection of large time sampled data sets and their conversion to the frequency domain for analysis.

Frequency analysis instrumentation for sinus wall and baroreceptor responses.

Blood pressure regulation involves feedback signals from baroreceptors detecting wall strain of arterial sinuses. A research goal is identification of wall viscoelastic properties and associations between elements and baroreceptors. This report presents development of computer-based procedures for control of pressure inputs and recording responses of an in situ carotid sinus.

Model inferences on baroreceptor & sinus wall responses.

Mechanical associations between sinus wall elements and those between wall and baroreceptor were modeled with differential equations. Viscoelastic relationships were tested using frequency domain analysis (TUTSIM, FANSIM). Two wall models were examined.

Cardiovascular responses to unilateral and bilateral stimulation of rabbit aortic nerves.

Reflex heart and mean arterial pressure (MAP) responses during unilateral and bilateral electrical stimulation of the central end of the cut aortic nerves were studied in 14 anesthetized closed-thorax rabbits. During control of carotid intrasinus pressure (ISP), with ISP = MAP, heart rate was 248 +/- 12 beats/min and fell -79 +/- 14, -61 +/- 16, and -117 +/- 16 beats/min during left (LAN), right (RAN), and bilateral (BAN) nerve stimulation. MAP was 79 +/- 5 mmHg and fell -57 +/- 4 (LAN), -46 +/- 6 (RAN), and -65 +/- 4 mmHg (BAN).