The evolving experience using everolimus in clinical transplantation

Everolimus is a derivative of sirolimus, a macrocyclic lactone, originally isolated from Streptomyces hygroscopicus. Both everolimus and sirolimus have a similar mechanism of action, exerting potent inhibition of growth factor-induced proliferation of lymphocytes, as well as other hematopoietic and nonhematopoietic cells of mesenchymal origin. Each agent complexes with the FK506 binding protein 12 to inhibit cyclin dependent kinase(s), collectively termed the target of rapamycin (TOR), causing G1-S phase cell cycle arrest. Safety and efficacy have been documented in large-scale, blinded, randomized, international clinical renal and cardiac transplant trials. Everolimus is more hydrophilic, exhibits a shorter elimination half-life (approximately 30 hours), and demonstrates greater relative bioavailability compared to sirolimus. However, similar to the calcineurin inhibitors and sirolimus, everolimus is biotransformed by the cytochrome P450, 3A4 isozyme. Also similar to sirolimus, clinical experiences identified biologically relevant side effects including hyperlipidemia and exacerbation of cyclosporine (CsA)-associated nephrotoxicity. However, also similar to sirolimus, accumulating evidence suggests that the hyperlipidemia can be controlled and the CsA-associated renal effects appear reduced with a low incidence of acute rejection when everolimus is administered in combination with reduced CsA doses. The experience using everolimus in cardiac transplantation has also provided potentially important insights into the consequences of antiproliferative effects on vascular smooth muscle cells and fibroblasts where reduction in intimal expansion was identified by intravascular coronary ultrasound examination among those patients receiving everolimus. Therefore, available results suggest that the introduction of everolimus as the newest TOR inhibitor should enhance therapeutic options for immunosuppression after organ transplantation.

Management of allergic rhinitis: a common part of practice in primary care clinics

BACKGROUND

Allergic rhinitis (AR) is an extremely common disease worldwide and one of the top-ten reasons for a visit to primary care clinics. This study aimed to investigate the understanding of current guidelines and concepts of management for AR among general practitioners (GPs) in Singapore.

METHODS

A postal questionnaire was designed to survey the dispensing practice and understanding of current guidelines in the management of AR among Singapore GPs.

RESULTS

Two hundred GPs completed the questionnaire. AR was estimated to be 10-40% of total patient visits in 50% of the primary care clinics surveyed. There was no significant difference in diagnosis and management of AR among GPs practicing solo, as a group or in polyclinics. The use of allergy tests (skin or in vitro tests) was <50%. Most physicians understood correctly the efficacy, side-effects, and cost effectiveness of first and newer generation H1-antihistamines and nasal glucocorticosteroids. However, first generation H1-antihistamines and oral/nasal decongestants are commonly used to reduce the cost of medication and to achieve quick relief from nasal obstruction.

CONCLUSION

Management of allergic rhinitis is common in primary care clinics. Quick symptomatic relief with low-cost medications is a major concern for GPs in the management of AR, as it will affect a patient's compliance and perception of efficacy. However, inappropriate use of decongestants and other nonevidence-based therapies should not be recommended. Implementing the current evidence-based international guidelines for AR needs to be improved.

Nanoscale solid-state quantum computing

Most experts agree that it is too early to say how quantum computers will eventually be built, and several nanoscale solid-state schemes are being implemented in a range of materials. Nanofabricated quantum dots can be made in designer configurations, with established technology for controlling interactions and for reading out results. Epitaxial quantum dots can be grown in vertical arrays in semiconductors, and ultrafast optical techniques are available for controlling and measuring their excitations. Single-walled carbon nanotubes can be used for molecular self-assembly of endohedral fullerenes, which can embody quantum information in the electron spin. The challenges of individual addressing in such tiny structures could rapidly become intractable with increasing numbers of qubits, but these schemes are amenable to global addressing methods for computation.

Sirolimus-based immunosuppression with reduce dose cyclosporine or tacrolimus after renal transplantation

Sirolimus (SRL), a fermentation product of Streptomyces hygroscopicus, complexes with the FKBP12 to inhibit cyclin dependent kinase(s), collectively termed the target of rapamycin (TOR), causing G(1)-S phase cell cycle arrest. Safety and efficacy have been documented in clinical renal transplantation, but concerns were raised due to important biologically relevant side effects. Hyperlipidemia was identified, beginning with early clinical experiences, and the unexpected findings that SRL may exacerbate CsA associated nephrotoxicity was observed during the pivotal phase III studies. This report details results of our experience using SRL (target trough concentration, 10-15 ng/mL) with low dose CsA (target trough concentration, 50-100 ng/mL), seeking to determine whether this approach might provide effective immunosuppression while reducing associated nephrotoxicity. Among 121 renal transplant recipients, 62 received the SRL based regimen and 59 received MMF with all patients receiving CsA and prednisone. Similar to earlier clinical experiences, hematopoeitic abnormalities and hyperlipidemia were observed among patients who received SRL, and those abnormalities were readily controlled. However, unlike observations from the phase III SRL studies, renal function was not adversely affected. These findings support the growing body of evidence indicating that SRL based immunosuppression in combination low dose calcineurin inhibitors and corticosteroids is safe, efficacious, and without associated renal toxicity.

Virulence of Rhizoctonia oryzae on Wheat and Barley Cultivars from the Pacific Northwest

Rhizoctonia oryzae (teleomorph = Waitea circinata) causes sheath spot of rice and root rot of wheat and barley. R. oryzae commonly is isolated from barley, wheat, and pea plants in eastern Washington and Idaho. Eight representative isolates were tested for virulence on spring barley (Hordeum vulgare cv. Baronesse), soft white winter wheat (Triticum aestivum cv. Madsen), and hard red spring wheat (cv. Scarlet) planted in natural soil in the greenhouse and maintained at 16°C. All isolates caused significant reduction of emergence in barley, but only seven of the eight isolates and one of the eight isolates reduced emergence of winter wheat and spring wheat, respectively. All isolates caused significant stunting and reduction in the number of seminal roots, root length, and number of root tips on wheat and barley. Some isolates also reduced the frequency of fine secondary roots, resulting in a reduction of the average root diameter. Spring barley was more susceptible to R. oryzae than winter or spring wheat. The main effects of both cultivar and isolate were significant, and there was a significant isolate-cultivar interaction. R. oryzae isolate 80042 was the most virulent on barley, whereas R. oryzae isolate 801387 was the most virulent on wheat. The two isolates from pea were intermediate in virulence on wheat and barley. When screening germ plasm for potential resistance, isolates exhibiting the maximum virulence for each host should be used.

Increased amyloid- levels in APPSWE transgenic mice treated chronically with a physiological high-fat high-cholesterol diet

Although plasma cholesterol levels are not generally associated with Alzheimer disease (AD) incidence, in vitro studies have found that increased cellular cholesterol levels are associated with increases in -amyloid (A ) production, with a concomitant decrease in sAPPa, the secreted non amyloidogenic fragment of the amyloid precursor protein (APP). In two previous studies using a mouse model for AD-like pathology, non-physiological high-cholesterol diet has been shown to increase plasma and cerebral cholesterol levels, but have resulted in conflicting results on cerebral A levels. In the present study APPSWE male transgenic mice were fed either a chow diet or a physiological high-fat high-cholesterol Western-type diet until the mice reached 1 year of age. Mice fed the Western type diet, compared to the low-fat chow diet, had increased body weight, plasma and cerebral cholesterol levels, as well as a 50% increase in cerebral A levels. Cerebral levels of total APP were not altered while cerebral apoE levels were increased in the mice fed the Western-type diet, versus the chow-fed mice. These data demonstrate that chronic intake of a non-toxic high-cholesterol diet, which is similar to a human diet in fat and cholesterol content, was effective in increasing A levels and further suggests that dietary cholesterol and/or fat may be a risk factor for AD.

Energy and phase velocity considerations required for attenuation and velocity measurements of anisotropic composites

Viscoelastic fibre-reinforced composite materials have a number of possible advantages for use in underwater acoustic applications. In order to exploit these materials it is important to be able to measure their complex stiffness matrix in order to determine their acoustic response. Ultrasonic transmission measurements on parallel-sided samples, employing broadband pulsed transducers at 2.25 MHz and an immersion method, have been used to determine the viscoelastic properties of a glass-reinforced composite with uniaxially aligned fibres. The composite measured was constructed from Cytecfiberite's CYCOM 919 E-glass. The theory of acoustic propagation in anisotropic materials shows that the direction of energy propagation is, in general, different from that given by Snell's Law. At 15 degrees incidence, Snell's Law implies a refracted angle of 40 +/- 2 degrees, whereas the energy direction is observed to be 70 +/- 2 degrees. Despite this, the experimental data indicates that the position of the receiving transducer has relatively little effect on the apparent phase velocity measured. The phase velocities measured at positions determined from the refracted angle and energy direction are 3647 and 3652 +/- 50 m s(-1), respectively. However, the amplitude of the received signal, and hence estimate of attenuation, is highly sensitive to the receiver position. This indicates that the acoustic Poynting vector must be considered in order to precisely determine the correct position of the receiving transducer for attenuation measurements. The beam displacement for a 17.6 mm sample at 15 degrees incidence is 9.5 and 40 mm by Snell's Law and Poynting's Theorem, respectively. Measured beam displacements have been compared with predictions derived from material stiffness coefficients. These considerations are important in recovering the complex stiffness matrix.

Rhinitis: do diagnostic criteria affect the prevalence and treatment?

BACKGROUND

Rhinitis is one of the world's most common health problems. Diagnostic criteria used in community surveys may affect reported prevalence and treatment.

METHODS

A proportionately stratified random sample study was performed to investigate the prevalence, comorbidities and management of community-based patients with rhinitis in the tropical urban city of Singapore.

RESULTS

The prevalence of at least one, two, three, or four nasal symptoms on most days during the past year in our study population was 25.5%, 13.1%, 6.5%, and 3.0%, respectively. Based on the definition of 'rhinitis' by the International Consensus Report (ICR), the prevalence was 13.1% in Singapore. There was significantly higher prevalence of self-reported allergy, asthma, and common cold/influenza-like illness among the rhinitis group. In the 53% of rhinitis subjects seeking for medical help, 71% visited a primary care physician and 20% an otolaryngologist. Treatments as reported by patients were decongestants (topical or oral) 27%, antibiotics 12%, antihistamines 6%, nasal steroids 3%, surgery 2%, traditional methods 28%, and 22% did not know what medication they had. Subjects considered the effectiveness of treatment unsatisfactory because the majority of them had only partial or no relief with any treatment.

CONCLUSIONS

The standardization of the definition of rhinitis in epidemiological studies is of crucial importance, especially when comparing the prevalence between studies. Appropriate patient education by physicians with a good understanding of the nature of rhinitis and the available treatment options (e.g. evidenced-based efficacy, safety, and a good cost-benefit ratio) will maximize patient compliance and treatment outcomes.

Cyclic stretch induces the expression of vascular endothelial growth factor in vascular smooth muscle cells

OBJECTIVE

Accumulating evidence links the release of vascular endothelial growth factor (VEGF) by vascular smooth muscle cells (VSMC) to normal endothelial cell (EC) function, repair and maintenance. Using an in vitro model we investigate the role of cyclic stretch on both the release of VEGF by VSMC and the phosphorylation of a VEGF receptor on EC.

METHODS

Bovine VSMC and EC were exposed to 10% cyclic strain for 4 hours. VEGF mRNA steady-state levels of VSMC were analysed by northern blot hybridisation. The presence of secreted VEGF from VSMC was determined by assaying the migration of EC. VEGF receptor phosphorylation on stretched EC was assayed by immunoblotting.

RESULTS

The steady-state level of VEGF mRNA in stretched VSMC increased 3.3 (+/- 0.6) fold above that of unstretched VSMC (p < 0.005). Migration of EC was stimulated 8.3 (+/- 1.1) and 14.6 (+/- 1.3) fold by media from unstretched and stretched VSMC respectively, demonstrating a 1.8 fold increase due to stretch alone (p < 0.05). Cyclic stretch resulted in phosphorylation of the VEGF receptor KDR.

CONCLUSION

Exposure of VSMC to physiological levels of stretch induces a biologically significant increase in VEGF secretion and may provide an arterial stimulus for maintenance of steady state levels of VEGF essential for EC survival.

Stably transfected ABCA1 antisense cell line has decreased ABCA1 mRNA and cAMP-induced cholesterol efflux to apolipoprotein AI and HDL

Using a sensitive real time fluorescent PCR assay, ABCA1 mRNA levels were induced by approximately 50-70-fold following 8Br-cAMP treatment of the RAW264 murine macrophage cell line, concomitant with the induction of cholesterol efflux to apoAI and HDL. A stably transfected ABCA1 antisense cDNA cell line was created, which led to approximately 50-70% reductions in ABCA1 mRNA levels in basal and 8Br-cAMP-treated cells, and diminished to the same extent the 8Br-cAMP-mediated efflux of cholesterol to apolipoprotein AI and HDL. These data demonstrate that ABCA1 is necessary for the cAMP-induced lipid efflux to both apoAI and HDL.

Adaptive immune responses of patients with asthma to the attachment (G) glycoprotein of respiratory synctial virus

A history of acute bronchiolitis in infancy caused by respiratory syncytial virus is a risk factor for recurrent wheezing in early childhood. Because the attachment (G) protein sensitizes mice for pulmonary eosinophilia and because Th2 cells are central in the pathogenesis of asthma, plasma and peripheral blood mononuclear cells (PBMC) from donors with asthma and from healthy donors were evaluated for anti-G protein responses. A significant trend connecting severity of asthma with anti-G protein IgG1 and IgG2 titers was observed. The correlation between anti-F protein IgG3 titers and asthma severity approached significance. Peptide mapping studies revealed that more positive recall responses (interferon-gamma and interleukin-10 secretion) occurred after PBMC from donors with asthma were stimulated with peptides representing the nonglycosylated domain of G protein. The same peptides elicited more positive recall responses (proliferation and interferon-gamma secretion) in the PBMC of healthy donors. These data suggest that a mechanism may exist whereby adaptive immune responses against G protein contribute to wheezing.

Journey to the center of the category: the dissociation in amnesia between categorization and recognition

The authors' theoretical analysis of the dissociation in amnesia between categorization and recognition suggests these conclusions: (a) Comparing to-be-categorized items to a category center or prototype produces strong prototype advantages and steep typicality gradients, whereas comparing to-be-categorized items to the training exemplars that surround the prototype produces weak prototype advantages and flat typicality gradients; (b) participants often show the former pattern, suggesting their use of prototypes; (c) exemplar models account poorly for these categorization data, but prototype models account well for them; and (d) the recognition data suggest that controls use a single-comparison exemplar-memorization process more powerfully than amnesics. By pairing categorization based in prototypes with recognition based in exemplar memorization, the authors support and extend other recent accounts of cognitive performance that intermix prototypes and exemplars, and the authors reinforce traditional interpretations of the categorization-recognition dissociation in amnesia.

Genetic modifiers of atherosclerosis in mice

Common atherosclerosis has a genetic component, but it is difficult to determine the specific genes that play a role in atherosclerosis susceptibility in humans. We have used the apoE-deficient mouse as a model system to examine the effects of candidate genes on atherosclerosis as well as to perform genomic experiments to map and isolate other genes giving rise to atherosclerosis susceptibility. We have tested the effects of mutations in the MCSF and VCAM-1 genes on atherosclerosis, and in both of these cases mutations led to gene dosage-dependent decreases in atherosclerosis. By successive back breeding, we have established apoE-deficiency on the C57BL/6 and FVB/N inbred mouse strains. Lesions in C57BL/6 mice are about eightfold larger than those in FVB/ N mice, and lesions in F1 hybrids are intermediate in size. We have performed quantitative trait locus mapping on two F2 cohorts and discovered atherosclerosis susceptibility loci on chromosomes 10, 14, and 19.

Brain region-specific up-regulation of mouse apolipoprotein E by pharmacological estrogen treatments

Cerebral apolipoprotein E (apoE) has been implicated in neuronal protection and repair. Due to the variable levels and types of estrogen receptors within different brain regions, the effect of estrogen on apoE and the mechanism of this effect may vary within different regions. Ovariectomized female C57BL/6 mice were treated with pharmacological levels of 17 beta-estradiol or placebo for 5 days, resulting in supraphysiological plasma levels of estradiol in the treated mice. ApoE and glial fibrillary acidic protein (GFAP) levels were measured in the cortex, hippocampus and diencephalon. 17 beta-Estradiol up-regulated apoE but not GFAP in the cortex and diencephalon, whereas in the hippocampus, GFAP and apoE were equally up-regulated. Treatment of estrogen receptor (ER) alpha knockout mice with 17 beta-estradiol or treatment of C57BL/6 mice with 17 alpha-estradiol, a poor estrogen receptor agonist, specifically induced apoE in the cortex, but not in the diencephalon. These results indicate that 17 beta-estradiol effects on apoE are either directly or indirectly mediated by ER alpha in the diencephalon, while the effects in the cortex may be mediated by a non-classical mechanism or by ER beta. Measurement of mRNA levels in estrogen versus placebo-treated wild-type mice indicated that the effect of 17 beta-estradiol on apoE was not associated with changes in apoE mRNA levels.

Decoding the language of var genes and Plasmodium falciparum sequestration

Sequestration and rosetting are key determinants of Plasmodium falciparum pathogenesis. They are mediated by a large family of variant proteins called P. falciparum erythrocyte membrane protein 1 (PfEMP1). PfEMP1 proteins are multispecific binding receptors that are transported to parasite-induced, 'knob-like' binding structures at the erythrocyte surface. To evade immunity and extend infections, parasites clonally vary their expressed PfEMP1. Thus, PfEMP1 are functionally selected for binding while immune selection acts to diversify the family. Here, we describe a new way to analyse PfEMP1 sequence that provides insight into domain function and protein architecture with potential implications for malaria disease.

Adhesion of monocytes to arterial endothelium and initiation of atherosclerosis are critically dependent on vascular cell adhesion molecule-1 gene dosage

- Vascular cell adhesion molecule-1 (VCAM-1/Vcam1) is a cytokine-inducible member of the immunoglobulin gene superfamily that is expressed by arterial endothelial cells in regions predisposed to atherosclerosis and at borders of atherosclerotic plaques. To determine whether VCAM-1 expression regulates atherosclerotic lesion formation, we crossed Vcam1 domain 4-deficient (D4D) mice, which partially circumvent the embryonic lethality of Vcam1 null mice, with apolipoprotein E null (Apoe(-/-)) mice, which spontaneously develop hypercholesterolemia and atherosclerosis. In the Apoe(-/-) background, mice homozygous for the Vcam1 D4D allele had markedly reduced arterial VCAM-1 expression, monocyte adherence in the aortic root, and fatty streak formation. Heterozygous Vcam1 D4D mice revealed a Vcam1 gene-dosage effect and had intermediate, yet significant, reductions in these parameters. Our data demonstrate that VCAM-1 plays a pivotal role in the initiation of atherosclerosis in Apoe(-/-) mice.

CpG containing oligodeoxynucleotides are potent adjuvants for parenteral vaccination with the fusion (F) protein of respiratory syncytial virus (RSV)

The feasibility of using oligodeoxynucleotides (ODN) containing unmethylated CpG motifs as parenteral adjuvants for subunit vaccines against RSV was tested in BALB/c mice. Compared with immunization with natural F protein adsorbed to aluminum hydroxide (F/AlOH) adjuvant alone, coadministration of F/AlOH with CpG ODN resulted in statistically significant increases in serum neutralization titers, an enhanced generation of splenic antigen-dependent killer cell precursors, and accelerated clearance of infectious virus from lungs 4 days after challenge. The statistically significant increases in serum IFNgamma and anti-F protein IgG2a titers, and significantly diminished pulmonary IL-5 and eosinophilia after challenge indicated that CpG ODN enhanced the ability of F/AlOH to elicit type 1 immune responses. F protein-specific serum IgE titers were also reduced. Further analysis of pulmonary inflammatory cells demonstrated an expansion of CD8(+) T cells, relative to the CD4(+) T cell compartment. The potency of CpG ODN was not adversely affected in gene knockout mice devoid of the p35 chain of the IL-12 heterodimer. Taken together, the results suggest a novel formulation for naïve recipients of F protein-based subunit vaccines that does not result in a type 2 phenotype.

A portable pulsed cavity ring-down transmissometer for measurement of the optical extinction of the atmospheric aerosol

A small portable system is described which is used to directly determine the optical extinction of the atmospheric aerosol. The requisite highly sensitive measurement of the optical extinction is accomplished simultaneously at two wavelengths in the near-infrared (1064 nm) and visible (532 nm), using the pulsed cavity ring-down (CRD) approach. The measurement at the two wavelengths can aid in separating the scattering and absorption components of the optical extinction. Rayleigh equivalent optical extinction of approximately 10 x 10(-6) m(-1) from particulate matter in the atmospherically important 0.1-2.5 pm diameter size range (fine particle accumulation mode) can be readily observed with short (<5 s) integration times. Optical extinction is inversely related to the visual range, and so the instrument provides a direct measurement of this particulate-related air quality indicator. The instrument can also provide particle size range-selected multiwavelength optical property measurements, which can be inverted to provide valuable information about the extant airborne particulate distribution.

Astrocytes down-regulate neuronal beta-amyloid precursor protein expression and modify its processing in an apolipoprotein E isoform-specific manner

Alzheimer's disease is the most frequent neurodegenerative disorder in the aged population and is characterized by the deposition of the 40/42-residue amyloid beta protein (A beta), a proteolytic fragment of the beta-amyloid precursor protein (APP). A common apolipoprotein E (apoE) polymorphism is associated with an increased risk of developing the disease. In order to assess the putative relationship between apoE and amyloidogenesis in the CNS, we prepared primary cortical neurons overexpressing humanized APP695 bearing the Swedish mutation (hAPP(695sw)) and we analysed APP expression and processing after: (i) coculture with primary astrocytes from wild-type, apoE-deficient (E0) mice, or mice overexpressing human apoE2, E3, or E4; (ii) treatment with conditioned media from apoE0, E2, E3 or E4 astrocytes; and (iii) treatment with human recombinant ApoE or human apoE purified from conditioned media of stably transfected RAW264 cells (E2, E3 and E4). Interestingly, a strong decrease in APP expression was observed only when neurons were cocultured with astrocytes (and independently of the apoE genotype considered), suggesting that cell-cell contact is required. Moreover, apoE4-secreting astrocytes, but not recombinant or purified apoE4, significantly increased A beta production and decrease sAPP alpha secretion only when cultured in direct contact with neurons, whereas apoE2 astrocytes had a protective effect. We conclude that astrocytes: (i) strongly regulate neuronal APP expression in primary neurons, and (ii) promote the amyloidogenic pathway in an apoE4-dependent manner. Thus, apoE and astrocytic factor(s) may modulate the pathogenesis of Alzheimer's disease.