Synthesis and release behavior of layered double hydroxides-carbamazepine composites.

Carbamazepine (CBZ) was incorporated into layered double hydroxides (LDH) to be used as a controlled drug system in solid tumors. CBZ has a formal charge of zero, so its incorporation in the anionic clay implies a challenge. Aiming to overcome this problem, CBZ was loaded into LDH with sodium cholate (SC), a surfactant with negative charge and, for comparison, without SC by the reconstruction method. Surprisingly, it was found that both resultant nanocomposites had similar CBZ encapsulation efficiency, around 75%, and the LDH-CBZ system without SC showed a better performance in relation to the release kinetics of CBZ in simulated body fluid (pH 7.4) and acetate buffer simulating the cellular cytoplasm (pH 4.8) than the system with SC. The CBZ dimensions were measured with Chem3D and, according to the basal spacing obtained from X-ray patterns, it can be arranged in the LDH-CBZ system as a monolayer with the long axis parallel to the LDH layers. Fourier transform infrared spectroscopy and solid state NMR measurements confirmed the presence of the drug, and thermogravimetric analyses showed an enhanced thermal stability for CBZ. These results have interesting implications since they increase the spectrum of LDH application as a controlled drug system to a large number of nonionic drugs, without the addition of other components.

Sex differences in insulin resistance in GABAB1 knockout mice.

AIMS: We have previously demonstrated that the absence of functional GABA B receptors (GABABRs) disturbs glucose homeostasis in GABAB1KO mice. The aim of this work was to extend our studies of these alterations in GABAB1KO mice and investigate the sexual differences therein. MAIN METHODS: Male and female, GABAB1KO and WT mice were used. Glucose and insulin tolerance tests (GTT and ITT), and insulin and glucagon secretion tests (IST and GST) were performed. Blood glucose, serum insulin and hyperglycemic hormones were determined, and HOMA-IR calculated. Skeletal muscle insulin receptor ß subunit (IRß), insulin receptor substrates 1/2 (IRS1, IRS2) and hexokinase-II levels were determined by Western blot. Skeletal muscle insulin sensitivity was assessed by in vivo insulin-induced Akt phosphorylation (Western blot). Food intake and hypothalamic NPY mRNA expression (by qPCR) were also evaluated. KEY FINDINGS: Fasted insulin and HOMA-IR were augmented in GABAB1KO males, with no alterations in females. Areas under the curve (AUC) for GTT and ITT were increased in GABAB1KO mice of both genders, indicating compromised insulin sensitivity. No genotype differences were observed in IST, GST or in IRß, IRS1, IRS2 and hexokinase-II expression. Akt activation was severely impaired in GABAB1KO males while no alterations were observed in females. GABAB1KO mice showed increased food intake and NPY expression. SIGNIFICANCE: Glucose metabolism and energy balance disruptions were more pronounced in GABAB1KO males, which develop peripheral insulin resistance probably due to augmented insulin secretion. Metabolic alterations in females were milder and possibly due to previously described reproductive disorders, such as persistent estrus.

Subdiffraction-limited focusing lens.

We describe techniques for making a diffractive optical element that produces a subdiffraction-limited spot size. We provide experimental verification, using a diffraction optical element that is constructed on a magneto-optic spatial light modulator.

Renal artery imaging: a prospective comparison of intra-arterial digital subtraction angiography with conventional angiography.

This study describes a systematic comparison of intra-arterial digital subtraction angiography (DSA) of the main renal arteries with conventional angiography (CA), the currently accepted "gold standard" for the diagnosis of renal artery stenosis. Twenty-five patients scheduled for abdominal aortography for various indications underwent first DSA then CA. The DSA and CA images were evaluated for number of renal arteries, presence and grade of renal artery stenosis, presence of post-stenotic dilation or fibromuscular changes, and diagnostic and pictorial adequacy of the images. DSA was found to be diagnostically adequate in 92% of cases, compared with 96% for CA. In evaluating significant main renal artery stenosis, which the authors assumed to be any stenosis greater than 50%, there were 10 such stenoses seen by CA. DSA also detected 10 cases, but there was 1 false positive and 1 false negative, yielding a sensitivity of 90% and a specificity of 98%. There was also close correlation of DSA and CA for the few cases of post-stenotic dilatation and fibromuscular dysplasia encountered. The authors conclude that DSA is an acceptable substitute for CA in the evaluation of patients for main renal artery stenosis.

In vitro fertilization: sonographic perspective.

The applications of sonography were evaluated in 220 patients undergoing 354 in vitro fertilization cycles. A baseline sonogram demonstrated adnexal abnormalities in 10.7% of cycles. Serial sonograms were beneficial in monitoring follicular development. Oocyte harvest was canceled in 18.4% of cycles owing to inadequate follicle growth progression, as demonstrated by ultrasound. An additional 9% of cycles were canceled owing to the development of a single lead follicle. Six percent of cycles were accompanied by a spontaneous rise in serum luteinizing hormone values, necessitating sonographic correlation to exclude ovulation.

Left lobe of the liver mimicking perisplenic collections.

Three patients were scanned in whom the sonographic diagnoses of perisplenic fluid collections were made. Computed tomography scanning demonstrated that the appearances were not caused by perisplenic pathology but by lateral extent of normal left lobe of the liver. Methods to avoid this potential sonographic pitfall are suggested.

Traumatic pulmonary artery aneurysm: CT evaluation.

We present a patient with penetrating thoracic trauma who demonstrated an ill-defined, enlarging pulmonary opacity over several days. Computed tomography confirmed the clinical suspicion of a pulmonary artery aneurysm.

Isolated external iliac artery aneurysm secondary to cystic medial necrosis.

The computed tomographic and angiographic findings of an isolated external iliac artery aneurysm secondary to cystic medial necrosis in a patient without Marfan's disease are demonstrated. A review of the differential diagnosis and surgical treatment of iliac artery aneurysms is presented. The dramatic surgical sequelae in this patient underscore the importance of preoperative consideration of this rare diagnosis.

Reversal of histopathologic pulmonary changes with indomethacin.

There are pulmonary changes documented by light and electron microscopy in a canine model of nonhypotensive shock induced by a lower limb tourniquet. These histopathologic changes are mediated, at least in part, when the dog is treated with indomethacin.