Effect of lipectomy on growth and development of hyperinsulinemia and hyperlipidemia in the Zucker rat

The Zucker fat rat inherits obesity and hyperinsulinemia, exhibits insulin resistance, and is, therefore, a model of adult onset, or type II, diabetes. The purpose of this study was to determine if excision of fat depots from the infant Zucker (fa+/fa+) rat would affect growth, fat cell number, hyperinsulinism, and hyperlipidemia. In the experimental design, 10 percent of the total body weight (inguinal and interscapular depots) was excised at 6 weeks of age from 18 fat and 18 lean (fa+/fa-) litter mates, with 18 fat and 18 lean rats serving as nonoperated controls. At intervals, serum glucose, insulin, cholesterol, and triglycerides were measured. Initially, the operated fat group was significantly (p < 0.01) lighter than the nonoperated group. By 9 weeks postoperatively, the operated fat rat group had regained weight and continued to grow at the same rate as the nonoperated fat rats because of intra-abdominal fat depots. Lipectomy had no effect on growth rate of the lean rat group. Although lipectomy caused no consistent change in serum glucose or insulin levels, it caused a significant decrease in lipid levels. For example, the operated fat rats had a reduction in cholesterol from 876 to 171 mg/dl by 15 weeks postoperatively, and serum cholesterol persisted at about 50 percent of the nonoperated group throughout the rest of the study (38 weeks postoperatively). Even a greater reduction in triglyceride levels occurred, for example, from 7415 to 1082 mg/dl at 24 weeks postoperatively. Lipectomy did not cause a change in lipid levels in the lean group. It is concluded that the lipectomy in the Zucker fat group is an excellent model to evaluate the effects of changes in fat cell number on lipid metabolism.     

Developmental patterns of acid hydrolases during differentiation of fetal mouse skin

A dye reduction method was developed for estimating total aerobic and/or psychrotrophic bacterial counts in ground beef. The method is based on color changes in indicator disks placed on the meat surface.     

Pyrolysis studies of organic oxygenates: 3. High temperature rearrangement of aryl alkyl ethers

Thermal chemistry pathways of aryl alkyl ethers have been investigated under coal conversion-like conditions. Anisole is a thermally reactive compound having an oxygen functionality found in such coal precursors as lignins. Pyrolysis of anisoles was carried out using small batch autoclaves. Under thermolysis conditions anisole yielded a product distribution strongly dependent upon experimental parameters. Phenol, methane, CO and benzaldehyde are the low molecular weight products and polyphenyls and polyethers are the predominant high molecular weight products. The generation of CO is explained by a high temperature rearrangement of the phenyl group from O- to C- followed by rapid thermal decarbonylation of the benzaldehyde. Carbon monoxide formation from aryl alkyl ethers can thus be an important mechanistic pathway in coal conversion processes. By investigating the rearrangement using para-fluoroanisole it was shown that this rearrangement proceeds via a three-centered intermediate to para-fluorobenzaldehyde. No meta isomer was observed.     

Proton MR spectroscopic findings in paroxysmal kinesigenic dyskinesia

Although paroxysmal kinesigenic dyskinesia (PKD) has characteristic clinical features, the pathophysiology of PKD has remained unknown. The purpose of this study was to investigate the pathophysiology of idiopathic PKD by performing proton magnetic resonance spectroscopy (1H-MRS) in five patients with idiopathic PKD. Three patients were familial and two sporadic. Single-voxel 1H-MRS was performed on a GE 1.5-T SIGNA MR system. Localized 1H-MR spectra were obtained from the basal ganglia (n = 5), thalamus (n = 3), and supplementary motor area (SMA; n = 4) using STEAM sequence (stimulated echo acquisition mode; TR = 3.0 sec, TE = 30 msec, 64 AVG, volume = 8 mL) or PRESS (point resolved spectroscopy; TR = 3.0 sec, TE = 135 msec, volume = 4 mL). Peak ratios of Cho/Cr (Cho: choline, Cr: creatine) and mI/Cr (mI: myoinositol) were decreased significantly in the unilateral basal ganglia of two patients. In one, decreased peak ratio of mI/Cr in the unilateral basal ganglia was the only abnormality. In the remaining two, there was no significant abnormality. 1H-MR spectra obtained from the thalamus and SMA were all within normal limits. In conclusion, these results suggest that underlying pathophysiological mechanism of PKD may be at least partially associated with the dysfunction of cholinergic system in the basal ganglia.     

Biologic characteristics of cultured human vitiligo melanocytes

BACKGROUND: Vitiligo is a pigmentary disorder of unknown cause characterized by depigmented patches due to destruction of melanocytes. Recently, the inherent cellular defect theory has been discussed. To investigate the biologic characteristics of cultured melanocytes from normal and vitiligo subjects, this study had the purpose to examine the functional and ultrastructural characteristics of these melanocytes and to observe the morphologic and functional changes of melanocytes in response to ultraviolet B irradiation. METHODS: Melanocytes were isolated and cultured from foreskin and arm skin of normal and vitiligo subjects. The DNA synthesis, tyrosinase activity assay, transmission and scanning electron microscopic examination, and the effects of ultraviolet B(UVB)-irradiation on cultured melanocytes were studied. RESULTS: Vitiligo melanocytes showed no significant differences in DNA synthesis and tyrosinase activity compared with normal melanocytes, but the vitiligo melanocytes contained dilated and/or circular rough endoplasmic reticulum (RER) on transmission electron microscopic examination. Exposure of the cultured melanocytes to UVB resulted in increased protein synthesis and tyrosinase activity. Morphologic alterations and changes in DNA synthesis were also noted. Compared with normal melanocytes, the responses of vitiligo melanocyte to UVB showed no significant difference. CONCLUSIONS: Normal and vitiligo melanocytes showed similar biologic characteristics except in the changes of RERs in the vitiligo melanocytes. The ultrastructural aberrations in vitiligo subjects do not seem to be directly related to the biologic characteristics and the responses to UVB irradiation in vitiligo melanocytes.     

Cyclic delay diversity with frequency domain turbo equalization for uplink fast fading channels

Cyclic delay diversity (CDD) is an attractive diversity technique due to its low complexity and compatibility to existing wireless communication systems. This letter proposes a CDD with frequency domain turbo equalization (FDTE) for single carrier (SC) transmission, in order to achieve the full spatial diversity of frequency-selective multi-antenna channels. The frequency diversity inherent in SC is picked up from the increased channel selectivity of CDD. The noise or intersymbol interference enhanced by equalization for highly selective channels is then mitigated through applying FDTE at the receiver. Simulation results show that the performance of proposed system approaches the corresponding orthogonal spacetime block coding (STBC) system in slowly fading channels without any data rate loss, and considerably outperforms the STBC system in fast fading channels.     

Fabrication of Ordered Nanostructured Arrays Using Poly(dimethylsiloxane) Replica Molds Based on Three‐Dimensional Colloidal Crystals

Hexagonally arrayed structures of colloidal crystals with uniform surface are a good candidate for master molds to be used in soft lithography. Here, the fabrication of periodically arrayed nanostructures using poly(dimethylsiloxane) (PDMS) molds based on three‐dimensionally (3D) ordered colloidal crystals is reported. A robust, high‐quality 3D colloidal‐crystal master molds is prepared using the colloidal suspension containing a water‐soluble polymer. The surface patterns of the 3D colloidal crystals can then be transferred onto a polymer film via soft lithography, by means of the replication of the surface pattern with PDMS. Various hexagonally arrayed nanostructure patterns can be fabricated, including close‐packed and non‐close‐packed 2D arrays and honeycomb structures by the structural modification of the 3D colloidal‐crystal templates. The replicated hexagonally arrayed structures can also be used as templates for producing colloidal crystals with 2D superlattices.     

Surface Modification of Exfoliated Layered Gadolinium Hydroxide for the Development of Multimodal Contrast Agents for MRI and Fluorescence Imaging

A novel method for modifying the surface of magnetic‐resonance‐contrasting layered gadolinium hydroxide (LGdH) is developed providing them with water‐ and bio‐compatibility and acid‐resistance, all of which are essential for medical applications. A stable colloid of exfoliated layers is synthesized by exchanging interlayer anions of LGdH with oleate ions. The delaminated layers are successively coated with phospholipids with poly(ethylene glycol) tail groups, and their effectiveness as a contrast agent for magnetic resonance imaging (MRI) is demonstrated. The adaptability of this surface modification approach for incorporating functional molecules and fabricating a fluorescent colloid of LGdH, which has the potential utility as a multimodal probe, is also demonstrated. This result provides a novel approach for expanding the applications of layered inorganic materials and developing a new class of MRI contrast agents.     

Preparation and characterization of proton conducting polysulfone grafted poly(styrene sulfonic acid) polyelectrolyte membranes

The syntheses of series of proton conducting comb copolymer membrane involving polysulfone back bone as main chain and poly(styrene sulfonic acid) (PSSA) being side chain, i.e. polysulfone grafted poly(styrene sulfonic acid) (PSU-g-PSSA) are presented. Chloromethylation of the polysulfone backbone was done by Fridel Craft alkylation reaction. Atom transfer radical polymerization was used for control grafting from the chloromethylated positions. The successful substitution of the chloromethyl group and its grafting with PSSA was characterized by elemental analysis and proton nuclear magnetic resonance. Water uptake, electrochemical properties like ion exchange capacity (IEC) and proton conductivities increase with increase in PSSA contents. Thermal gravimetric analysis (TGA) showed the thermal stability of membranes up to 250 °C. Proton conductivity for maximum amount of grafting is 0.02 S/cm.