Quantification of gene expression patterns to reveal the origins of abnormal morphogenesis.

The earliest developmental origins of dysmorphologies are poorly understood in many congenital diseases. They often remain elusive because the first signs of genetic misregulation may initiate as subtle changes in gene expression, which are hard to detect and can be obscured later in development by secondary effects. Here, we develop a method to trace back the origins of phenotypic abnormalities by accurately quantifying the 3D spatial distribution of gene expression domains in developing organs. By applying Geometric Morphometrics to 3D gene expression data obtained by Optical Projection Tomography, we determined that our approach is sensitive enough to find regulatory abnormalities that have never been detected previously. We identified subtle but significant differences in the gene expression of a downstream target of a Fgfr2 mutation associated with Apert syndrome, demonstrating that these mouse models can further our understanding of limb defects in the human condition. Our method can be applied to different organ systems and models to investigate the etiology of malformations.

Influence of subcutaneous administration of rapid-acting insulin in the quality of (18)F-FDG PET/CT studies.

OBJECTIVE: The aim of this study was to develop a protocol for normalizing blood glucose levels in diabetic patients by subcutaneously administering rapid-acting insulin before administering (18)F-fluorodeoxyglucose ((18)F-FDG) without hindering the quality of PET/computed tomography (CT) studies. MATERIALS AND METHODS: The study included 120 patients, who were divided into four groups: Group I: This group comprised 30 diabetic patients with blood glucose levels lower than 160 mg/dl at the time of arrival at our center; in these patients, (18)F-FDG was injected without prior administration of subcutaneous rapid-acting insulin. Group II: This group comprised 30 diabetic patients with blood glucose levels ranging from 168 to 260 mg/dl; in these patients, subcutaneous rapid-acting insulin was administered and then (18)F-FDG was injected when blood glucose levels dropped below 160 mg/dl (30-115 min). Group III: This group included 30 diabetic patients with blood glucose levels ranging from 192 to 324 mg/dl; in these patients, subcutaneous rapid-acting insulin was administered and then (18)F-FDG was injected 4 h later. Blood glucose levels dropped below 160 mg/dl (range, 58-159 mg/dl) in all patients. CONTROL GROUP: This group included 30 nondiabetic patients with normal blood glucose levels (72-104 mg/dl). We calculated the mean standardized uptake value (SUV) of muscle from the maximum SUV in five consecutive axial slices in the proximal middle third of the rectus femoris muscle of the right thigh. RESULTS: The quality of the PET-CT studies was considered suboptimal when muscle uptake was more than 2 SDs greater than the mean muscle uptake in the control group (1.15±0.2). The mean SUV of muscle was as follows: Group I, 1.09 (σ=0,26); group II, 1.98 (σ=0,32); group III, 1.98 (σ=1,13); and control group IV, 1.15 (σ=0,2). The quality of PET-CT studies was considered suboptimal in 18 patients in group II (60%) and in four patients (13%) in group I. The quality was optimal in all studies conducted in group III patients. CONCLUSION: Subcutaneous administration of rapid-acting insulin normalizes blood glucose levels without compromising the quality of PET-CT studies when (18)F-FDG is administered not earlier than 4 h later.

Determination of drug, excipients and coating distribution in pharmaceutical tablets using NIR-CI.

The growing interest of the pharmaceutical industry in Near Infrared-Chemical Imaging (NIR-CI) is a result of its high usefulness for quality control analyses of drugs throughout their production process (particularly of its non-destructive nature and expeditious data acquisition). In this work, the concentration and distribution of the major and minor components of pharmaceutical tablets are determined and the spatial distribution from the internal and external sides has been obtained. In addition, the same NIR-CI allowed the coating thickness and its surface distribution to be quantified. Images were processed to extract the target data and calibration models constructed using the Partial Least Squares (PLS) algorithms. The concentrations of Active Pharmaceutical Ingredient (API) and excipients obtained for uncoated cores were essentially identical to the nominal values of the pharmaceutical formulation. But the predictive ability of the calibration models applied to the coated tablets decreased as the coating thickness increased.

First investigation of non-classical dihydrogen bonding between an early transition-metal hydride and alcohols: IR, NMR, and DFT approach.

The interaction of [NbCp(2)H(3)] with fluorinated alcohols to give dihydrogen-bonded complexes was studied by a combination of IR, NMR and DFT methods. IR spectra were examined in the range from 200-295 K, affording a clear picture of dihydrogen-bond formation when [NbCp(2)H(3)]/HOR(f) mixtures (HOR(f) = hexafluoroisopropanol (HFIP) or perfluoro-tert-butanol (PFTB)) were quickly cooled to 200 K. Through examination of the OH region, the dihydrogen-bond energetics were determined to be 4.5+/-0.3 kcal mol(-1) for TFE (TFE = trifluoroethanol) and 5.7+/-0.3 kcal mol(-1) for HFIP. (1)H NMR studies of solutions of [NbCp(2)H(2)(B)H(A)] and HFIP in [D(8)]toluene revealed high-field shifts of the hydrides H(A) and H(B), characteristic of dihydrogen-bond formation, upon addition of alcohol. The magnitude of signal shifts and T(1) relaxation time measurements show preferential coordination of the alcohol to the central hydride H(A), but are also consistent with a bifurcated character of the dihydrogen bonding. Estimations of hydride-proton distances based on T(1) data are in good accord with the results of DFT calculations. DFT calculations for the interaction of [NbCp(2)H(3)] with a series of non-fluorinated (MeOH, CH(3)COOH) and fluorinated (CF(3)OH, TFE, HFIP, PFTB and CF(3)COOH) proton donors of different strengths showed dihydrogen-bond formation, with binding energies ranging from -5.7 to -12.3 kcal mol(-1), depending on the proton donor strength. Coordination of proton donors occurs both to the central and to the lateral hydrides of [NbCp(2)H(3)], the former interaction being of bifurcated type and energetically slightly more favourable. In the case of the strong acid H(3)O(+), the proton transfer occurs without any barrier, and no dihydrogen-bonded intermediates are found. Proton transfer to [NbCp(2)H(3)] gives bis(dihydrogen) [NbCp(2)(eta(2)-H(2))(2)](+) and dihydride(dihydrogen) complexes [NbCp(2)(H)(2)(eta(2)-H(2))](+) (with lateral hydrides and central dihydrogen), the former product being slightly more stable. When two molecules of TFA were included in the calculations, in addition to the dihydrogen-bonded adduct, an ionic pair formed by the cationic bis(dihydrogen) complex [NbCp(2)(eta(2)-H(2))(2)](+) and the homoconjugated anion pair (CF(3)COO...H...OOCCF(3))(-) was found as a minimum. It is very likely that these ionic pairs may be intermediates in the H/D exchange between the hydride ligands and the OD group observed with the more acidic alcohols in the NMR studies.