Identification of highly transformable wheat genotypes for mass production of fertile transgenic plants

The efficiency of wheat biolistic transformation systems strongly depends on the bombardment parameters, the condition of the donor plant, and the plant genotype chosen for the transformation process. This paper analyzes the transformation efficiency of the 129 wheat sister lines generically called 'Bobwhite', originally obtained from the cross 'Aurora'//'Kalyan'/'Bluebird 3'/'Woodpecker'. A number of factors influencing the transformation were examined, such as the ability to produce embryogenic callus, regeneration in selection medium, and overall transformation performance. Of the 129 genotypes evaluated, eight demonstrated transformation efficiencies above 60% (60 independent transgenic events per 100 immature embryos bombarded). Among the eight genotypes identified, we studied agronomic characteristics such as earliness to identify the most adaptable line(s) for different lab conditions. 'Bobwhite' SH 98 26 was identified as a super-transformable wheat line.

Ceramide mediates insulin resistance by tumor necrosis factor-alpha in brown adipocytes by maintaining Akt in an inactive dephosphorylated state

Tumor necrosis factor (TNF)-alpha causes insulin resistance on glucose uptake in fetal brown adipocytes. We explored the hypothesis that some effects of TNF-alpha could be mediated by the generation of ceramide, given that TNF-alpha treatment induced the production of ceramide in these primary cells. A short-chain ceramide analog, C2-ceramide, completely precluded insulin-stimulated glucose uptake and insulin-induced GLUT4 translocation to plasma membrane, as determined by Western blot or immunofluorescent localization of GLUT4. These effects were not produced in the presence of a biologically inactive ceramide analog, C2-dihydroceramide. Analysis of the phosphatidylinositol (PI) 3-kinase signaling pathway indicated that C2-ceramide precluded insulin stimulation of Akt kinase activity, but not of PI-3 kinase or protein kinase C-zeta activity. C2-ceramide completely abolished insulin-stimulated Akt/protein kinase B phosphorylation on regulatory residues Thr 308 and Ser 473, as did TNF-alpha, and inhibited insulin-induced mobility shift in Akt1 and Akt2 separated in PAGE. Moreover, C2-ceramide seemed to activate a protein phosphatase (PP) involved in dephosphorylating Akt because 1) PP2A activity was increased in C2-ceramide- and TNF-alpha-treated cells, 2) treatment with okadaic acid concomitantly with C2-ceramide completely restored Akt phosphorylation by insulin, and 3) transient transfection of a constitutively active form of Akt did not restore Akt activity. Our results indicate that ceramide produced by TNF-alpha induces insulin resistance in brown adipocytes by maintaining Akt in an inactive dephosphorylated state.

Mycotic pseudoaneurysm associated with aortic coarctation

Development of a mycotic aneurysm or pseudoaneurysm after subacute bacterial endarteritis is uncommon. Nonetheless, patients with coarctation of the aorta are more likely to develop this complication. We describe a case of a large pseudoaneurysm discovered in a child with a previously undiagnosed aorta coarctation. Successful repair was performed with the aid of partial left heart bypass and the use of an interposition graft. A high index of suspicion is necessary to accurately diagnose this rare but life-threatening entity.

A minimalist model protein with multiple folding funnels

Kinetic and structural studies of wild-type proteins such as prions and amyloidogenic proteins provide suggestive evidence that proteins may adopt multiple long-lived states in addition to the native state. All of these states differ structurally because they lie far apart in configuration space, but their stability is not necessarily caused by cooperative (nucleation) effects. In this study, a minimalist model protein is designed to exhibit multiple long-lived states to explore the dynamics of the corresponding wild-type proteins. The minimalist protein is modeled as a 27-monomer sequence confined to a cubic lattice with three different monomer types. An order parameter-the winding index-is introduced to characterize the extent of folding. The winding index has several advantages over other commonly used order parameters like the number of native contacts. It can distinguish between enantiomers, its calculation requires less computational time than the number of native contacts, and reduced-dimensional landscapes can be developed when the native state structure is not known a priori. The results for the designed model protein prove by existence that the rugged energy landscape picture of protein folding can be generalized to include protein "misfolding" into long-lived states.

Acute stent thrombosis visualized by intravascular ultrasound

Subacute stent thrombosis is currently a rare but feared complication in patients undergoing coronary intervention. Intravascular ultrasound is a useful technique to guide stent implantation. However, its value in patients suffering from acute stent thrombosis has not been described. Herein, we present the intravascular ultrasound findings of a patient experiencing ongoing stent thrombosis and impending vessel closure.

Akt mediates insulin induction of glucose uptake and up-regulation of GLUT4 gene expression in brown adipocytes

Insulin acutely stimulated glucose uptake in rat primary brown adipocytes in a PI3-kinase-dependent but p70S6-kinase-independent manner. Since Akt represents an intermediate step between these kinases, this study investigated the contribution of Akt to insulin-induced glucose uptake by the use of a chemical compound, ML-9, as well as by transfection with a dominant-negative form of Akt (DeltaAkt). Pretreatment with ML-9 for 10 min completely inhibited insulin stimulation of (1) Akt kinase activity, (2) Akt phosphorylation on the regulatory residue Ser473 but not on Thr308, and (3) mobility shift in Akt1 and Akt2. However, ML-9 did not affect insulin-stimulated PI3-kinase nor PKCzeta activities. In consequence, ML-9 precluded insulin stimulation of glucose uptake and GLUT4 translocation to plasma membrane (determined by Western blot), without any effect on the basal glucose uptake. Moreover, DeltaAkt impaired insulin stimulation of glucose uptake and GFP-tagged GLUT4 translocation to plasma membrane in transiently transfected immortalised brown adipocytes and HeLa cells, respectively. Furthermore, ML-9 treatment for 6 h down-regulated insulin-induced GLUT4 mRNA accumulation, without affecting GLUT1 expression, in a similar fashion as LY294002. Indeed, co-transfection of brown adipocytes with DeltaAkt precluded the transactivation of GLUT4-CAT promoter by insulin in a similar fashion as a dominant-negative form of PI3-kinase. Our results indicate that activation of Akt may be an essential requirement for insulin regulation of glucose uptake and GLUT4 gene expression in brown adipocytes.

Exposure to low pH is not required for penetration of mosquito cells by Sindbis virus

It is widely held that the penetration of cells by alphaviruses is dependent on exposure to the acid environment of an endosome. The alphavirus Sindbis virus replicates in both vertebrate and invertebrate cell cultures. We have found that exposure to an acid environment may not be required for infection of cells of the insect host. In this work, we investigated the effects of two agents (NH(4)Cl and chloroquine), which raise the pH of intracellular compartments (lysosomotropic weak bases) on the infection and replication of Sindbis virus in cells of the insect host Aedes albopictus. The results show that both of these agents increase the pH of endosomes, as indicated by protection against diphtheria toxin intoxication. NH(4)Cl blocked the production of infectious virus and blocked virus RNA synthesis when added prior to infection. Chloroquine, in contrast to its effect on vertebrate cells, had no inhibitory effect on infectious virus production in mosquito cells even when added prior to infection. Treatment with NH(4)Cl did not prevent the penetration of virus RNA into the cell cytoplasm or translation of the RNA to produce a precursor to virus nonstructural proteins. These data suggest that while these two drugs raise the pH of endosomes, they do not block insect cell penetration. These data support previous results published by our laboratory suggesting that exposure to an acid environment within the cell may not be an obligatory step in the process of infection of cells by alphaviruses.

Identification of a point mutation in an esterase gene in different populations of the southern cattle tick, Boophilus microplus

Two esterase cDNA sequences were obtained from susceptible and organophosphorus resistant strains of Boophilus microplus. Both sequences have a high degree of homology to carboxylesterase B. One gene has identical sequences in both strains and the other showed two point mutations. One mutation produces an amino acid substitution when the amino acid sequence is deduced, this mutation was detected in six different populations susceptible and resistant to insecticides, but a pyrethroid resistant strain was the only one that showed only the mutant allele. Identification of this mutation and the strong signal detected in southern blot with this strain, suggest that esterases are contributing to detoxification of pyrethroid compounds, as a resistant mechanism in Mexican strains of the southern cattle tick.

A single deletion in the membrane-proximal region of the Sindbis virus glycoprotein E2 endodomain blocks virus assembly

The envelopment of the Sindbis virus nucleocapsid in the modified cell plasma membrane involves a highly specific interaction between the capsid (C) protein and the endodomain of the E2 glycoprotein. We have previously identified a domain of the Sindbis virus C protein involved in binding to the E2 endodomain (H. Lee and D. T. Brown, Virology 202:390-400, 1994). The C-E2 binding domain resides in a hydrophobic cleft with C Y180 and W247 on opposing sides of the cleft. Structural modeling studies indicate that the E2 domain, which is proposed to bind the C protein (E2 398T, 399P, and 400Y), is located at a sufficient distance from the membrane to occupy the C protein binding cleft (S. Lee, K. E. Owen, H. K. Choi, H. Lee, G. Lu, G. Wengler, D. T. Brown, M. G. Rossmann, and R. J. Kuhn, Structure 4:531-541, 1996). To measure the critical spanning length of the E2 endodomain which positions the TPY domain into the putative C binding cleft, we have constructed a deletion mutant, DeltaK391, in which a nonconserved lysine (E2 K391) at the membrane-cytoplasm junction of the E2 tail has been deleted. This mutant was found to produce very low levels of virus from BHK-21 cells due to a defect in an unidentified step in nucleocapsid binding to the E2 endodomain. In contrast, DeltaK391 produced wild-type levels of virus from tissue-cultured mosquito cells. We propose that the phenotypic differences displayed by this mutant in the two diverse host cells arise from fundamental differences in the lipid composition of the insect cell membranes which affect the physical and structural properties of membranes and thereby virus assembly. The data suggest that these viruses have evolved properties adapted specifically for assembly in the diverse hosts in which they grow.

Immunostaining of heat shock proteins in the retina and optic nerve head of normal and glaucomatous eyes

PURPOSE

To examine immunostaining of 60-kd and 27-kd heat shock proteins (HSP 60 and HSP 27), which are known to increase cell survival in response to stress, in glaucomatous retina and optic nerve head.

METHODS

Six postmortem eyes from patients with primary open-angle glaucoma, 6 eyes from patients with normal-pressure glaucoma, and 6 eyes from age-matched normal subjects were studied by immunohistochemistry. The sections of the retina and optic nerve head were examined after immunostaining with antibodies to HSP 60 and HSP 27.

RESULTS

The intensity of the immunostaining and the number of labeled cells for heat shock proteins (HSPs) were greater in retina sections from glaucomatous eyes than in sections from normal eyes from age-matched donors. Retinal immunostaining of HSP 60 was prominent in the retinal ganglion cells and photoreceptors, whereas immunostaining of HSP 27 was prominent in the nerve fiber layer and ganglion cells as well as in the retinal vessels. In addition, retinal immunostaining of these HSPs exhibited regional and cellular differences. Optic nerve heads of glaucomatous eyes exhibited increased immunostaining of HSP 27, but not HSP 60, which was mostly associated with astroglial cells in the lamina cribrosa.

CONCLUSION

The increased immunostaining of HSP 60 and HSP 27 in the glaucomatous eyes may reflect a role of these proteins as a cellular defense mechanism in response to stress or injury in glaucoma.

CLINICAL RELEVANCE

These findings suggest that immunoregulation is an important component of glaucomatous optic neuropathy.

Effect of bilateral ovariectomy and ovarian steroid hormones on the antioxidant systems and plasma malondialdehyde levels in Wistar rats

We studied in the Wistar rat the effect of bilateral ovariectomy and of the administration of estradiol (E2) alone or together with medroxyprogesterone (MPA) on the lipid peroxidation (MDA) and the enzymatic (SOD and catalase) and non-enzymatic (vitamins A and E) antioxidant systems. At 15 days after castration, we observed no variations in the lipid peroxidation levels (MDA), with there being a slight increase in vitamins A and E (p<0.05), catalase (p<0.01), and SOD (n.s.) activity. The addition of estradiol led to a decline (n.s.) in the MDA values and in the catalase and SOD activity, with no modification of the vit. A and E concentrations. The combined (E2+MPA) therapy did not modify the results obtained with E2 alone, although the catalase decline did now reach significance (p<0.05).

Faculty perspectives of health promotion in allied health curricula: results of a national survey

More knowledge and skills related to health promotion/disease prevention are being required of health professionals. Allied health graduates entering the workforce will need academic preparation in these areas. This study assessed faculty perspectives on the status of health promotion content in allied health programs by a survey of 524 program directors. A questionnaire gathered information about perception of importance, level of representation, and method of delivery of health promotion content. Response rate was 41%. The majority of participants thought this content area was important for their programs and was highly or moderately represented in their curricula. Level of representation was significantly associated with requirement for accreditation. Programs in the Northeast were more likely to think health promotion was important and those in the West were more likely to have it integrated into their curricula. The most common delivery modality was guest lecture. Allied health is adopting health promotion curricular content, but further study is needed to assess programs and faculty expertise and identify strategies to ensure greater consistency of delivering material.

Allogeneic peripheral blood cell transplantation for hypereosinophilic syndrome with myelofibrosis

Patients with hypereosinophilic syndrome (HES) display a very heterogeneous clinical picture ranging from asymptomatic cases to very aggressive forms. We report a 38-year-old woman with progressive HES who developed severe myelofibrosis and was treated by allogeneic stem cell transplantation, using peripheral blood (PBSCT) instead of bone marrow as the source of progenitor cells, after conditioning with cytoxan and busulphan. To the best of our knowledge, this is the first case of HES with myelofibrosis treated with PBSCT. The patient remains alive 8 months post-PBSCT, and bone marrow fibrosis has significantly decreased following transplantation. Bone Marrow Transplantation (2000) 25, 217-218.

Propensity and mechanisms of restenosis in different coronary stent designs: complementary value of the analysis of the luminal gain-loss relationship

OBJECTIVES

This study sought to investigate the influence of stent design on the long-term angiographic outcome.

BACKGROUND

The proportional relationship between vessel injury and late luminal loss in percutaneous revascularization should be best appreciated in coronary stenting, where recoil and shrinkage are theoretically minimal. It is unclear whether all stent designs can counterbalance this reactive loss by achieving a large initial luminal gain (bigger is better).

METHODS

In 523 lesions successfully stented, the long-term angiographic results of slotted-tube (n = 331), coil (n = 85), multicellular (n = 70) and self-expandable mesh (n = 37) stent designs were compared using the angiographic gain-loss relationship (GLR).

RESULTS

Restenosis rate was 10% for multicellular, 20% for slotted-tube, 46% for coil and 49% for self-expandable designs (p = 0.001). At a difference with other designs, no significant GLR was found in coil stents, suggesting additional mechanisms of luminal loss (i.e., plaque protrusion, stent compression) to neointimal proliferation. Significant differences in late loss between stents were found within each quartile of luminal gain, suggesting a specific role of design in luminal loss. Multivariate analysis identified use of coil and self-expandable stents, vessel size, minimal luminal diameter preintervention, luminal gain and stent length as variables with independent predictive value for several indices of angiographic long-term outcome.

CONCLUSIONS

The analysis of GLR: 1) demonstrates that stent design influences late luminal loss; 2) challenges the applicability of the widely accepted "bigger is better" approach to all stent designs; and 3) appears as a valuable tool in assessing long-term stent performance.

Cloning and sequencing of a putative acetylcholinesterase cDNA from Boophilus microplus (Acari: Ixodidae)

Using a strategy based on degenerate primers derived from acetylcholinesterase (AChE) from other species, we cloned and sequenced a putative AChE cDNA from the southern cattle tick, Boophilus microplus (Canestrini). The sequence has a high degree of homology to sequences of AChE from other species reported in the GenBank. The open reading frame of 1,689 bp, corresponding to a deduced sequence of 563 amino acids, has conserved regions and features shared by the AChE family, necessary for its catalytic activity. No differences were found in the putative cDNA sequences from organophosphorus acaricide (OP) resistant and susceptible strains. The results suggest that this putative AChE gene is not involved in resistance to OP compounds as a mutated gene in the resistant strain studied. However, differences were detected, with a probe derived from this cDNA, in DNA fragments after digestion of genomic DNA from different strains with restriction nucleases. This indicates polymorphism in this gene in B. microplus.

Long-term angiographic results of stenting in chronic total occlusions: influence of stent design and vessel size

BACKGROUND

Although coronary stenting has decreased the high restenosis rate associated with percutaneous transluminal coronary angioplasty of chronic total occlusions (CTOs), the results are still less satisfactory than those found in nonoccluded lesions, at least as reported with the Palmaz-Schatz stent. The present work compares the restenosis rate of other stent designs with that of the Palmaz-Schatz stent.

METHODS

We studied the long-term angiographic outcome of 120 CTOs successfully recanalized with balloon-expandable stents and without concomitant debulking techniques. Angiographic follow-up and full quantitative coronary angiography analysis was prospectively performed in all patients. Three different stent designs were compared: Palmaz-Schatz (n = 47), coil (n = 24), and multicellular (n = 49). Particular attention was paid to their performance in vessels of 3 mm or less and greater than 3 mm in diameter. Restenosis was defined as a 50% or greater diameter stenosis at follow-up.

RESULTS

Multicellular stents were implanted more frequently in the left anterior descending artery and in patients with multivessel disease. No other significant differences in clinical or angiographic baseline characteristics, including vessel size, were noted between groups. At follow-up, multicellular stents presented a lower restenosis rate (22% vs 36% and 58% in the Palmaz-Schatz and coil stent groups, respectively; P =.01 ) and larger minimal luminal diameters (1.92 +/- 0.85 mm vs 1.73 +/- 0.98 and 1.38 +/- 0.83 mm in the Palmaz-Schatz and coil stent groups, respectively; P = 0.0). The superiority of the multicellular stent design resulted from a lower restenosis rate in vessels of 3.0 mm or less in diameter (20% vs 47% and 79% in the Palmaz-Schatz and coil stent groups, respectively; P =.006).

CONCLUSIONS

These results suggest that the restenosis rate after stent recanalization of CTOs is influenced by both stent design and vessel size and may indicate a superiority of multicellular over Palmaz-Schatz and coil stent designs for this purpose.