The block to HIV-1 envelope glycoprotein-mediated membrane fusion in animal cells expressing human CD4 can be overcome by a human cell component(s)

Membrane fusion mediated by interaction of the human immunodeficiency virus type 1 (HIV-1) envelope glycoprotein with the human CD4 molecule generally requires that the CD4 be expressed on a human cell. The failure of murine or simian cells expressing human CD4 to form syncytia upon mixing with cells expressing envelope glycoprotein could not be corrected by expression of both molecules at extremely high surface levels using vaccinia virus expression vectors. Video fluorescence microscopic analysis of fluorescent dye transfer between fusing cells indicated that the block occurred at the level of membrane fusion between individual pairs of cells. To gain insight into the basis for this fusion block, we tested the ability of fluorescent probe cells expressing envelope glycoprotein to fuse with transient animal x human hybrid giant cells expressing human CD4. The hybrid giant cells were generated either by low-pH-induced fusion of vaccinia-infected cells or by CD4/HIV-1 envelope glycoprotein-mediated cell fusion. We observed that envelope glycoprotein-expressing probe cells efficiently fused with CD4-expressing animal x human hybrid giant cells, independent of whether the CD4 was originally expressed on the animal or on the human cell. Fusion did not occur with CD4-expressing giant cells derived from animal cells alone. These results indicate that the fusion block is not due to dominant inhibitory components in the animal cell. Rather, they suggest that human cells contain an additional component(s) which, when transferred to the CD4-bearing animal cell, confers the ability to undergo membrane fusion mediated by the HIV-1 envelope glycoprotein.     

Analysis of a grating metal structure with broad back-scatteringfield pattern for applications in vehicle collision avoidancesystem

In this paper, grating metal structures with broad and flat back-scattering field patterns are studied for possible applications in a vehicle collision avoidance system. The two-dimensional TE scattering of a planar grating structure and a curved grating structure are analyzed at a frequency of 77 GHz. For the planar structure, the method of moments and Floquet's theorem are used to solve the induced current and the resultant back-scattering field. Based on the results of the planar structure, the scattering field of the curved grating structure is obtained by using a perturbation method. The influence on the field pattern of the curvature as well as other structure parameters, such as the width and geometry of each period in the grating structure, is investigated     

Growth temperature dependence of low-noise MESFET in molecular-beam epitaxy

The substrate growth temperature dependence of electrical properties for a low-noise MESFET fabricated on MBE-grown material has been demonstrated. The optimum noise figure and its associated gain were attributed to the higher epilayer quality and mobility at a growth temperature of 650°C between temperatures of 550°C and 700°C.     

Hypertrophic olivary degeneration: case report in a child

We report a case of hypertrophic olivary degeneration (HOD) detected by MRI, in a 14-year-old girl, 13 months after surgical excision of a brainstem cavernous malformation. As in vivo diagnosis of this condition has only become possible with the advent of MRI, the number of reported cases remains relatively small and they are almost exclusively in adults. Many radiologists and particularly paediatric radiologists, may therefore be unfamiliar with this entity. To our knowledge, this is the first specific report of HOD diagnosed by MRI in a child.     

Delta opioid peptide [D-Ala2,D-leu5]enkephalin blocks the long-term loss of dopamine transporters induced by multiple administrations of methamphetamine: involvement of opioid receptors and reactive oxygen species

Delta opioid peptide [D-Ala2,D-leu5]enkephalin (DADLE) can prolong organ preservation and increases myocardial tolerance to ischemia. Our study examined the protective property of DADLE against methamphetamine- (METH) induced dopaminergic terminal damage in the central nervous system. Because the neurotoxicity of METH involves reactive oxygen species, we also examined if DADLE might be an antioxidative agent in vitro. DADLE at 2 and 4 mg/kg (i.p.), given 30 min before each METH administration (5 or 10 mg/kg, i.p., four injections in a day at 2-hr intervals), dose-dependently blocked the METH-induced long-term dopamine transporter loss. The opioid antagonist naltrexone blocked this action of DADLE in both aspects of striata but tends not to affect the effects of DADLE in the nucleus accumbens. DADLE did not alter changes in body temperature induced by METH. The reduction of striatal dopaminergic content and tyrosine hydroxylase activity caused by METH, however, were not blocked by DADLE. In vitro, DADLE was approximately equipotent to glutathione in inhibiting both superoxide anion formation induced by xanthine oxidase and hydroxyl radical formation evoked by ferrous/citrate complex. DADLE was only slightly less potent than glutathione in inhibiting the iron/ascorbate-induced brain lipid peroxidation. These results suggest that DADLE can protect the terminal membranes of dopaminergic neurons against METH-induced insult but not the loss of dopaminergic content and tyrosine hydroxylase activity and that this action of DADLE might involve opioid receptors as well as the sequestration of free radical.     

SPARC deficiency leads to early-onset cataractogenesis

PURPOSE: To determine the role of SPARC (secreted protein, acidic, and rich in cysteine) in cataractogenesis by examining mice deficient in a matricellular protein SPARC. METHODS: Mice were rendered SPARC-deficient by a targeted disruption of the gene. Slit-lamp microscopy and histology were used to examine the eyes of SPARC-null and wild-type mice from birth to 14 months of age. RESULTS: SPARC-null mice developed opacities in the posterior cortex of the eye as early as 1.5 months after birth. The diffuse cataracts appeared to progress toward the anterior cortex and reached maturity in many animals by 3.5 months of age. Early stages of cataractogenesis in SPARC-null mice included inhibition of normal lens fiber cell differentiation, degeneration of fiber cells, vacuole formation at the equator, and liquefaction of the cortex. No cataracts were detected in wild-type mice up to the age of 8 months. CONCLUSIONS: The early onset of cataracts in SPARC-null mice establishes that the gene is essential to the maintenance of lens transparency.     

Self-care behaviors, self-efficacy, and social support effect on the glycemic control of patients newly diagnosed with non-insulin-dependent diabetes mellitus

The purpose of this study was to explore the glycemic control and influencing factors in outpatients newly diagnosed with non-insulin-dependent diabetes mellitus (NIDDM). By purposeful sampling, data were collected from 130 outpatients with NIDDM at one medical center in Kaohsiung. The results indicated: (1) the mean value for HbA1C was 7.12%; and 63.1% of the patients belonged to moderate to well controlled group; (2) male patient's HbA1C value was significantly lower than female patient's; patients with no religious belief also had a lower HbA1C value than patients with a religious background; (3) there were strongly negative correlations between self-care behaviors, social support, and self-efficacy and HbA1C; (4) using a multiple stepwise regression analysis, religious belief and self-care behaviors were found to explain 10.9% variance of HbA1C level. The results of this study could be used as a reference for diabetes health education program.