Protease inhibitors (PIs) effectively inhibit replication of the human immunodeficiency virus (HIV), and reduce mortality and prolong survival in patients with HIV infection. Newer PIs saquinavir ...(soft gelatin capsule) and amprenavir, as well as other PIs, may be effective when administered twice/day. Adverse reactions may occur, as well as metabolic complications and interactions between PIs and other drugs, including other PIs. The strategy of combining PIs is based on specific pharmacologic interactions among the agents.
Mammalian small heat-shock proteins (sHSPs) are molecular chaperones that form polydisperse and dynamic complexes with target proteins, serving as a first line of defense in preventing their ...aggregation into either amorphous deposits or amyloid fibrils. Their apparently broad target specificity makes sHSPs attractive for investigating ways to tackle disorders of protein aggregation. The two most abundant sHSPs in human tissue are αB-crystallin (ABC) and HSP27; here we present high-resolution structures of their core domains (cABC, cHSP27), each in complex with a segment of their respective C-terminal regions. We find that both truncated proteins dimerize, and although this interface is labile in the case of cABC, in cHSP27 the dimer can be cross-linked by an intermonomer disulfide linkage. Using cHSP27 as a template, we have designed an equivalently locked cABC to enable us to investigate the functional role played by oligomerization, disordered N and C termini, subunit exchange, and variable dimer interfaces in ABC. We have assayed the ability of the different forms of ABC to prevent protein aggregation in vitro. Remarkably, we find that cABC has chaperone activity comparable to that of the full-length protein, even when monomer dissociation is restricted through disulfide linkage. Furthermore, cABC is a potent inhibitor of amyloid fibril formation and, by slowing the rate of its aggregation, effectively reduces the toxicity of amyloid-β peptide to cells. Overall we present a small chaperone unit together with its atomic coordinates that potentially enables the rational design of more effective chaperones and amyloid inhibitors. PUBLICATION ABSTRACT
Relatively little is known about how members of minority groups cope with experiences such as diagnosis and treatment of breast cancer - in particular, whether coping patterns among minorities differ ...from that of the majority. This study adds to the existing knowledge base using a cross-sectional sample of middle-class African-American (n = 26), Hispanic (n = 59), and non-Hispanic White women (n = 151) who had been treated for early stage breast cancer in the past year. We tested for differences in coping responses per se and also for the possibility that coping would relate to distress differently in different groups. There were only two differences in coping (controlling for medical variables, education, and distress): compared to non-Hispanic White women, the other two groups both reported using humor-based coping less, and religion-based coping more. There was one difference in how coping related to distress: venting related more strongly to elevated distress among Hispanic than among non-Hispanics. Discussion centers on a growing consensus on ethnic differences in religious and humor-based coping, and on the relative absence of other coping differences among these populations.
Objective:
To review the pharmacology, microbiology, chemistry, in vitro susceptibility, pharmacokinetics, clinical efficacy, safety, tolerability, dosage, and administration of dalbavancin, a new ...semisynthetic lipoglycopeptide.
Data Sources:
A MEDLINE search, restricted to the English language, was conducted from 1966 through January 2006. Supplementary sources included program abstracts from the Interscience Conference on Antimicrobial Agents and Chemotherapy, American Society of Microbiology, and the Infectious Diseases Society of America from 2000 to 2005 and information available from the manufacturer's Web site.
Study Selection and Data Extraction:
In vitro and preclinical studies, as well as Phase I, II, and III clinical trials, were evaluated to summarize the microbiology, pharmacology, clinical efficacy, and safety of dalbavancin. All published trials and abstracts citing dalbavancin were selected.
Data Synthesis:
Dalbavancin, a novel lipoglycopeptide, has a mechanism of action similar to that of other glycopeptides. It has in vitro activity against a variety of gram-positive organisms, but no activity against gram-negative or vancomycin-resistant enterococci that possess VanA gene. Due to its prolonged half-life (6–10 days), dalbavancin can be administered intravenously once weekly. In Phase II and III clinical trials, dalbavancin was effective and well tolerated for the treatment of skin and soft-tissue infections, catheter-related bloodstream infections, and skin and skin-structure infections. To date, adverse events are mild and limited; the most common include pyrexia, headache, nausea, oral candidiasis, diarrhea, and constipation.
Conclusions:
Dalbavancin appears to be a promising antimicrobial agent for the treatment of gram-positive infections. A new drug application was filed with the Food and Drug Administration (FDA) in December 2004. The FDA issued an approvable letter in 2005 for dalbavancin. If approved, dalbavancin is expected to be launched in the first quarter of 2006.
A series of hydantoin derivatives has been discovered as highly potent nonpeptide antagonists for the human CCR5 receptor. The synthesis, SAR, and biological profiles of this class of antagonists are ...described.
A series of hydantoin derivatives has been discovered as highly potent nonpeptide antagonists for the human CCR5 receptor. The synthesis, SAR, and biological profiles of this class of antagonists are described.
As breast cancer survival increases, cardiotoxicity associated with chemotherapeutic regimens such as anthracyclines and trastuzumab becomes a more significant issue. Assessment of the left ...ventricular (LV) ejection fraction fails to detect subtle alterations in LV function. The objective of this study was to evaluate whether more sensitive echocardiographic measurements and biomarkers could predict future cardiac dysfunction in chemotherapy-treated patients. Forty-three patients diagnosed with breast cancer who received anthracyclines and trastuzumab therapy underwent echocardiography and blood sampling at 3 time points (baseline and 3 and 6 months during the course of chemotherapy). The LV ejection fraction; peak systolic myocardial longitudinal, radial, and circumferential strain; echocardiographic markers of diastolic function; N-terminal pro–B-type natriuretic peptide; and high-sensitivity cardiac troponin I were measured. Nine patients (21%) developed cardiotoxicity (1 at 3 months and 8 at 6 months) as defined by the Cardiac Review and Evaluation Committee reviewing trastuzumab. A decrease in longitudinal strain from baseline to 3 months and detectable high-sensitivity cardiac troponin I at 3 months were independent predictors of the development of cardiotoxicity at 6 months. The LV ejection fraction, parameters of diastolic function, and N-terminal pro–B-type natriuretic peptide did not predict cardiotoxicity. In conclusion, cardiac troponin plasma concentrations and longitudinal strain predict the development of cardiotoxicity in patients treated with anthracyclines and trastuzumab. The 2 parameters may be useful to detect chemotherapy-treated patients who may benefit from alternative therapies, potentially decreasing the incidence of cardiotoxicity and its associated morbidity and mortality.
Objective. To determine linezolid concentrations in peritoneal dialysis fluid after multiple oral doses of the drug in a 46‐year‐old man with vancomycin‐resistant Enterococcus faecium peritonitis who ...was undergoing peritoneal dialysis.
Methods. After administration of oral linezolid 600 mg twice/day was started, peritoneal dialysis fluid was collected at the end of several 4‐ and 8‐hour dwell times and submitted for analysis of linezolid concentration. Before linezolid therapy was begun, and immediately after several peritoneal dialysis exchanges, 30 ml of expended peritoneal dialysis fluid was collected in a sterile container and immediately frozen at −70°C until analysis by high‐performance liquid chromatography.
Results. Peritoneal dialysis concentrations of linezolid greater than 4 μg/ml were achieved after the first dose of linezolid and maintained after repeated doses. During the course of therapy, mean linezolid concentrations in peritoneal dialysis fluid tended to increase (mean 7.60 μg/ml, range 3.54–16.2 μg/ml). All assayed peritoneal dialysis samples demonstrated linezolid concentrations greater than 4 μg/ml at the end of 4‐ or 8‐hour dwell times, except for one level after a missed dose on linezolid treatment day 3. Duration of dwell times did not appear to correlate with linezolid concentrations.
Conclusion. In this patient, linezolid 600 mg twice/day penetrated into peritoneal dialysis fluid at or above the concentrations necessary to treat common gram‐positive bacteria. Linezolid therapy is likely to have a role in peritoneal dialysis‐associated peritonitis based on its antimicrobial activity, pharmacokinetic properties, ease of administration, and tolerability.
Objectives The aim of this study was to determine if individual or multiple biomarkers are associated with cardiotoxicity in patients with breast cancer undergoing cancer therapy. Background Current ...methods to identify patients at risk for cardiotoxicity from cancer therapy are inadequate. Methods We measured 8 biomarkers in a multicenter cohort of 78 patients with breast cancer undergoing doxorubicin and trastuzumab therapy: ultrasensitive troponin I (TnI), high-sensitivity C-reactive protein (CRP), N-terminal pro–B-type natriuretic peptide (NT-proBNP), growth differentiation factor (GDF)-15, myeloperoxidase (MPO), placental growth factor (PlGF), soluble fms-like tyrosine kinase receptor (sFlt)-1, and galectin (gal)-3. Cardiotoxicity, defined by the Cardiac Review and Evaluation Committee criteria, was assessed every 3 months for up to 15 months. Hazard ratios (HRs) of cardiotoxicity risk were assessed for each biomarker at baseline, at visit 2 (3 months), and as a function of the difference between visit 2 and baseline. Joint models were assessed for the most promising biomarkers. Results TnI, CRP, GDF-15, MPO, PlGF, and sFlt-1 levels increased from baseline to visit 2 (p < 0.05). A greater risk of cardiotoxicity was associated with interval changes in TnI (HR: 1.38 per SD; 95% confidence interval: 1.05 to 1.81; p = 0.02) and MPO (HR: 1.34 per SD; 95% confidence interval: 1.00 to 1.80; p = 0.048) and in models combining both markers (p = 0.007 and p = 0.03, respectively). The risk of cardiotoxicity was 46.5% in patients with the largest changes in both markers (ΔTnI >121.8 ng/l; ΔMPO >422.6 pmol/l). Conclusions Early increases in TnI and MPO levels offer additive information about the risk of cardiotoxicity in patients undergoing doxorubicin and trastuzumab therapy. Independent validation of these findings is necessary before application to clinical practice.
Single nucleotide polymorphisms (SNPs) are ideally suited for the construction of high-resolution genetic maps, studying population evolutionary history and performing genome-wide association mapping ...experiments. Here, we used a genome-wide set of 1536 SNPs to study linkage disequilibrium (LD) and population structure in a panel of 478 spring and winter wheat cultivars (Triticum aestivum) from 17 populations across the United States and Mexico.
Most of the wheat oligo pool assay (OPA) SNPs that were polymorphic within the complete set of 478 cultivars were also polymorphic in all subpopulations. Higher levels of genetic differentiation were observed among wheat lines within populations than among populations. A total of nine genetically distinct clusters were identified, suggesting that some of the pre-defined populations shared significant proportion of genetic ancestry. Estimates of population structure (F(ST)) at individual loci showed a high level of heterogeneity across the genome. In addition, seven genomic regions with elevated F(ST) were detected between the spring and winter wheat populations. Some of these regions overlapped with previously mapped flowering time QTL. Across all populations, the highest extent of significant LD was observed in the wheat D-genome, followed by lower LD in the A- and B-genomes. The differences in the extent of LD among populations and genomes were mostly driven by differences in long-range LD ( > 10 cM).
Genome- and population-specific patterns of genetic differentiation and LD were discovered in the populations of wheat cultivars from different geographic regions. Our study demonstrated that the estimates of population structure between spring and winter wheat lines can identify genomic regions harboring candidate genes involved in the regulation of growth habit. Variation in LD suggests that breeding and selection had a different impact on each wheat genome both within and among populations. The higher extent of LD in the wheat D-genome versus the A- and B-genomes likely reflects the episodes of recent introgression and population bottleneck accompanying the origin of hexaploid wheat. The assessment of LD and population structure in this assembled panel of diverse lines provides critical information for the development of genetic resources for genome-wide association mapping of agronomically important traits in wheat.
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