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Purpose: Recent progress suggests that short peptide motifs can be engineered into biopolymers with specific temperature dependent behavior. This review discusses peptide motifs capable of thermo-responsive behavior, and broadly summarizes design approaches that exploit these peptides as drug carriers. This review focuses on one class of thermally responsive peptide-based biopolymers, elastin-like polypeptides in greater detail., Analysis: Four peptide motifs are presented based on leucine zippers, human collagen, human elastin, and silkworm silk that are potential building blocks for thermally responsive biopolymers. When these short motifs (<7 amino acids) are repeated many times, they generate biopolymers with higher order structure and complex temperature triggered behaviors. These structures are thermodynamically modulated, making them intrinsically temperature sensitive. These four motifs can be categorized by the directionality and reversibility of association. Elastin-like polypeptides (ELPs) are one promising motif that reversibly associates during heating. ELPs aggregate sharply above an inverse phase transition temperature, which depends on polymer hydrophobicity, molecular weight, and concentration. ELPs can be modified with chemotherapeutics, are biodegradable, are biocompatible, have low immunogenicity, and have terminal pharmacokinetic half-lives >8 h. ELP block copolymers can reversibly form micelles in response to hyperthermia, and this behavior can modulate the binding avidity of peptide ligands. When high molecular weight ELPs are systemically administered to mice they accumulate in tumors; furthermore, hyperthermia can initiate the ELP phase transition and double the concentration of peptide in the tumor., Conclusions: Temperature sensitive peptides are a powerful engineering platform that will enable new strategies for hyperthermia-directed drug delivery.

We evaluated gene transfer using PEGylated bioresponsive nanolipid particles (NLPs) containing plasmid DNA administered by convection-enhanced delivery (CED) into orthotopically implanted U87-MG tumors in rat brain. We hypothesized that attachment of the human immunodeficiency virus trans-acting transcriptional activator peptide (TATp) to pH-sensitive, reduction-sensitive NLPs would increase gene transfer. TATp was attached either directly to a phospholipid (TATp-lipid) or via a 2-kd polyethylene glycol (PEG) to a lipid (TATp-PEG-lipid). Incorporation of 0.3 mol% TATp-PEG into pH-sensitive NLPs improved transfection 100,000-fold compared to NLPs in culture. In the brain or implanted tumors, the TATp-PEG restricted NLP convection to regions adjacent to the infusion catheter. Gene transfer in the brain from TATp-PEG NLPs, measured by green fluorescent protein (GFP) expression, was substantially greater than from NLPs adjacent to the catheter. Gene transfer using TATp-PEG NLPs, measured by luciferase expression, was 8-12-fold greater than from a 1,2-dioleoyl-3-trimethylammonium-propane/cholesterol cationic lipoplex but 13-27-fold less than from the NLPs. Brain luciferase expression was localized in perivascular macrophages. Thus a cationic ligand, such as the TATp-PEG-lipid, can dramatically increase gene expression in culture, in the normal brain, and in implanted tumors; however, restriction of NLP distribution to the vicinity of the infusion catheter reduces the absolute level of gene transfer.

Question: What is the efficacy of pharmacologic and non-pharmacologic treatments for major depression and other depressive disorders in cancer populations?, Perspectives: Depression occurs at an increased rate in medically ill populations, including patients with cancer. In the general population, depression has been shown to be responsive to structured forms of psychotherapy and to pharmacologic interventions. The Supportive Care Guidelines Group conducted a systematic review of the evidence for the effectiveness of those therapies in patients with depression and cancer and developed the present clinical practice guideline based on that review and on expert consensus., Outcomes: Outcomes of interest included symptomatic response to treatment, discontinuation rate of treatment, adverse effects, and quality of life., Methodology: Clinical recommendations were developed by the Supportive Care Guidelines Group based on a systematic review of the published literature through June 2005, feedback obtained from Ontario health care providers on the draft recommendations, the Report Approval Panel (rap) of Cancer Care Ontario's Program in Evidence-Based Care, and expert consensus., Results: The systematic review of the literature included eleven trials (seven of pharmacologic agents and four of non-pharmacologic interventions). Feedback received from 44 responding health care providers and the rap on the draft recommendations was addressed and documented in the guideline. Among providers, 82% agreed with the draft recommendations as stated, 68% agreed that the report should be approved as a practice guideline, and 73% indicated that they would be likely to use the guideline in their own practice., Practice Guideline: These recommendations apply to adult cancer patients with a diagnosis of major depression or other non-bipolar depressive disorders. They do not address the treatment of non-syndromal depressive symptoms, for which specific antidepressant treatment is not usually indicated. The guideline is intended both for oncology health professionals and for mental health professionals engaged in the treatment of cancer patients. Expert consensus was central to the development of the guideline recommendations because of limited evidence in cancer patients., Recommendations: Treatment of pain and other reversible physical symptoms should be instituted before or with initiation of specific antidepressant treatment. Antidepressant medications should be considered for the treatment of moderate-to-severe major depression in cancer patients. Current evidence does not support the relative superiority of one pharmacologic treatment over another, nor the superiority of pharmacologic treatment over psychosocial interventions. The choice of an antidepressant should be informed by individual medication and patient factors: the side effect profiles of the medication, tolerability of treatment (including the potential for interaction with other current medications), response to prior treatment, and patient preference. Cancer patients diagnosed with major depression may benefit from a combined modality approach that includes both psychosocial and pharmacologic interventions. Psychosocial treatment approaches that may be of value include those that provide information and support and those that address any combination of emotional, cognitive, and behavioural factors., Qualifying Statements: Referral to a mental health specialist is appropriate when the diagnosis of depression is unclear, when the syndrome is severe, when patients do not respond to treatment, or when other complicating factors that may affect the choice of treatment are present. Although care has been taken in the preparation of the information contained in this guideline, any person seeking to apply or to consult the guideline is expected to use independent medical judgment in the context of individual clinical circumstances or to seek out the supervision of a qualified clinician.

This paper reports an improvement in the purification of thioredoxin (Trx) expressed from E. coli by inverse transition cycling (ITC) using cationic elastin-like polypeptides (ELPs). Two ELP libraries having 2% and 5% lysine residues and molecular weights ranging from 4 to 61.1 kDa showed greater salt sensitivity in their inverse transition behavior than purely aliphatic ELPs. Expression yield of Trx-ELP fusions was an unpredictable function of guest residue composition, but reducing the molecular weight of the ELP tag generally increased Trx yield. A cationic 4.3 kDa ELP is the shortest ELP used to purify any protein by ITC to date. A 15.9 kDa ELP with a guest residue composition of K:V:F of 1:7:1 was found to be the optimal cationic tag to purify Trx, as it provided 50% greater Trx yield and only required one-fifth the added NaCl for purification of Trx as compared to previously used aliphatic ELP tags.

Goals of the Work: To evaluate the efficacy of pharmacological and nonpharmacological treatments for depression in cancer populations., Materials and Methods: The Supportive Care Guidelines Group conducted a systematic review of the published literature through June 2005. Search sources includes MEDLINE, EMBASE, CINAHL, PsycInfo, and the Cochrane Library. Comparative studies of treatments for depression in cancer patients were selected for review by two group members based on predefined criteria., Main Results: Seven trials of pharmacological agents and four of nonpharmacological interventions were identified. Two trials detected a significant reduction in depressive symptoms for mianserin compared with placebo, and one trial found alprazolam to be superior to progressive muscle relaxation. Four drug trials found no significant difference between groups on depression measures although posttreatment reduction of symptoms was observed for all groups in two trials comparing active treatments (fluoxetine vs desipramine and paroxetine vs amitriptyline). Of the four trials involving nonpharmacological therapies for the management of depression, two detected a benefit for treatment (a multicomponent nurse delivered intervention and an orientation program) over usual care., Conclusion: There is limited evidence for the effectiveness of pharmacological and psychosocial interventions in the treatment of cancer patients with depressive disorders, and no evidence for the superiority of one treatment modality over another. Based on evidence from the general population and other medically ill populations, combined approaches to the treatment of depression may be the most effective. Further research is necessary in cancer patients to determine the relative effectiveness of psychosocial, pharmacological, and combined treatments.

Elastin-like polypeptides (ELPs) are artificial polypeptides, derived from Val-Pro-Gly-Xaa-Gly (VPGXG) pentapeptide repeats found in human tropoelastin, that reversibly coacervate above a critical temperature. Genetically encodable ELPs are monodisperse, stimuli responsive, and biocompatible, properties that make them attractive for drug delivery and tissue engineering. The potential of ELPs to self-assemble into nanostructures in response to environmental triggers is another interesting feature of these polypeptides that promises to lead to a host of new applications.

Purpose: This clinical practice guideline, based on a systematic review, evaluates second-line or subsequent therapy for patients with recurrent or progressive non-small cell lung cancer., Methods: Relevant randomized trials and meta-analyses were identified through a systematic search of the literature. External feedback was obtained from practitioners in Ontario, and the guideline was approved by the provincial Lung Cancer Disease Site Group., Results: Twenty-four randomized trials met the eligibility criteria. Two phase III trials demonstrated a significant benefit in overall survival and quality of life (QOL) for single-agent docetaxel. A pooled analysis comparing docetaxel administered weekly versus three-weekly found similar survival between the schedules and a non-significant reduction in febrile neutropenia for the weekly regimen. One phase III trial found that single-agent pemetrexed provided similar survival and QOL, compared to docetaxel. Another phase III trial demonstrated that oral topotecan was non-inferior to docetaxel for one-year survival rate, although QOL significantly favored docetaxel over topotecan. Docetaxel-based and other combination chemotherapy regimens have not been shown to be superior to single-agent docetaxel. One phase III trial revealed a statistically significant survival and QOL benefit for erlotinib over placebo for patients who were not eligible for further chemotherapy. Modest tumor response rates and symptom control have been demonstrated for gefitinib; however, a statistically significant survival benefit has not been established for gefitinib over placebo., Conclusion: Second-line or subsequent therapy with single-agent docetaxel, pemetrexed, or erlotinib offers patients a significant survival and QOL advantage.

Introduction: Inhibition of the epidermal growth factor receptor is a promising therapy in the treatment of non-small cell lung cancer (NSCLC). In this systematic review, we evaluated the role of the epidermal growth factor receptor inhibitors gefitinib and erlotinib in the treatment of patients with advanced NSCLC., Methods: Relevant randomized trials published as articles or abstracts were identified through a systematic search of the literature from 1975 to November 2005 by two independent reviewers., Results: Twelve randomized trials met the predefined eligibility criteria for this systematic review. Four large placebo-controlled trials demonstrated that the addition of gefitinib or erlotinib to platinum-based first-line chemotherapy did not significantly improve overall survival or time-to-disease progression. A large placebo-controlled trial revealed a clinically and statistically significant survival benefit for erlotinib therapy as second- or third-line systemic therapy. The results of a single placebo-controlled trial and two phase II trials suggest that modest tumor response rates and symptom control can be achieved with gefitinib as second-line or subsequent therapy; however, a statistically significant survival benefit was not found for gefitinib compared with placebo., Conclusion: There is strong evidence to recommend against the use of gefitinib or erlotinib in combination with chemotherapy or as maintenance therapy after chemotherapy and radiation as a first-line treatment for advanced NSCLC. Erlotinib monotherapy is an effective treatment that can prolong survival for patients with advanced NSCLC whose disease has relapsed or recurred after prior chemotherapy. Although a significant survival benefit has not been demonstrated for gefitinib in a placebo-controlled study, the two randomized phase II trials suggest that gefitinib may provide clinically important symptomatic benefits.

Purpose: To conduct a systematic review and to evaluate the impact of postoperative adjuvant chemotherapy on the survival of patients with completely resected non-small cell lung cancer., Methods: Relevant randomized trials and meta-analyses, published as articles or abstracts, were identified through electronic and hand searches by two reviewers., Results: Seven meta-analyses and 26 randomized trials comparing surgery with or without chemotherapy met the pre-defined eligibility criteria for the review. The meta-analyses all showed a survival advantage for platinum- or UFT-based postoperative chemotherapy, although the results did not always achieve statistical significance. The results of individual trials were inconsistent, although recent trials have detected a large survival advantage with postoperative platinum-based chemotherapy. Differences in trial design, patient characteristics, disease stage, use of radiotherapy and chemotherapy regimen may explain the variation in results., Conclusions: Postoperative adjuvant platinum-based chemotherapy improves survival compared with surgery alone in completely resected non-small cell lung cancer. In patients fit for chemotherapy, the survival benefits strongly outweigh the adverse effects of the treatment.

A systematic review of the evidence for postoperative chemotherapy in completely resected nonsmall cell lung cancer was conducted. Seven meta-analyses and 25 randomized trials met the pre-defined eligibility criteria for the review. The evidence indicates that postoperative platinum-based chemotherapy improves survival compared with surgery alone; for patients with a good performance status who are fit enough for chemotherapy, the survival benefits strongly outweigh the adverse effects of treatment. To date the trials restricted to stage IB or II disease have obtained the greatest survival benefits with postoperative platinum-based chemotherapy. The evidence does not support the use of postoperative radiotherapy with chemotherapy.

Purpose: To conduct a systematic review to determine the most effective therapy for patients with unresected stage III non-small cell lung cancer., Methods: Relevant randomized trials and meta-analyses were identified through a systematic search of the literature., Results: Forty-seven trials and six meta-analyses were included. No statistically significant survival differences were detected for immediate versus delayed administration of radiotherapy or different doses of hyperfractionated radiotherapy. Three of 12 trials comparing various doses and schedules of radiotherapy detected a statistically significant survival advantage with higher radiation doses. All meta-analyses found a statistically significant survival advantage for chemoradiation, particularly platinum-based, compared with radiation alone. One meta-analysis and three trials comparing concurrent with sequential chemoradiation detected a statistically significant survival advantage with concurrent administration. Increased toxicities, especially esophagitis and hematologic events, were generally associated with concurrent chemoradiation. The survival advantage for concurrent platinum-based chemoradiation corresponds to a 4% absolute survival benefit at 2 years. With respect to trials comparing different chemotherapy regimens or schedules, there is insufficient evidence to determine which particular regimen or schedule is most effective., Conclusion: Palliative radiotherapy can provide symptom relief for symptomatic patients with poor performance status. For patients with good performance status, chemoradiation improves survival compared with radiotherapy alone, particularly when the two modalities are administered concurrently. Sequential chemoradiation is a treatment option for borderline-status patients. Adequate assessment of performance status is important when evaluating treatment options for patients with unresected non-small cell lung cancer. Patients and physicians should have a full discussion of the benefits, limitations, and toxicities of therapy.

[structure: see text] Synthesis of chiral phosphines 1a, 14a, and 18a as nucleophilic catalysts for anhydride activation and kinetic resolution of alcohols is described. Radical cyclization of alkenylphosphines produced the phosphabicyclooctane (PBO) core of catalysts 1a and 14a, while 18a was made by quenching a metallocycle precursor with dichlorophenylphosphine. Catalysts 1a and 14a are less reactive, while 18a is comparable to the most reactive catalysts in the PBO family. The preferred ground-state geometries of phosphine-boranes were identified using computational methods, and were correlated with the catalytic reactivity of the corresponding free phosphines.

The use of pH-sensitive liposomes for acid-triggered site-specific drug delivery is one of the more promising approaches to improve the therapeutic index of drugs. Here, we report the synthesis, assembly, and hydrolysis of the first ortho ester phosphocholine (OEPC). The acid hydrolysis of OEPC liposomes consists of a lag phase and a burst phase. The lag time is pH-dependent-the lower the pH, the shorter the time. Upon acid hydrolysis, the OEPC liposomes were transformed into leaky metastable vesicles that rapidly collapsed in the presence of albumin. OEPC, when formulated with cationic lipid, significantly enhanced the transfection efficiency compared with that of the pH-insensitive formulation.

Purpose: Practitioner feedback (PF) surveys are sent to practitioners who care for lung cancer patients as each new practice guideline is completed. In this study, the PF was reviewed to assess the frequency of response to the surveys, the respondents' characteristics, the nature of the feedback, and the intention to adopt the guideline in practice., Methods: Fourteen practice guidelines (PGs) were sent to Ontario practitioners treating lung cancer, and feedback on the PGs was obtained through either an eight- or 21-item survey., Results: Between 1995 and 2002, 1198 surveys were sent to 223 practitioners. The overall response rate was 58.9% but varied by specialty (radiation and medical oncologists, 67%; thoracic surgeons, 46%; respirologists, 38%), by location of practice (cancer center, 65%; community-based practice, 55%), by geographic region of the province (highest, 72%; lowest, 42%), and by PG topic (chemotherapy, 60%; radiotherapy, 63%; combined modality therapy, 52%). The response rate to the PF surveys did not decline over time. Eighty-six percent of respondents agreed with the lung cancer guidelines and indicated that they were likely or very likely to use the PGs in their practice., Conclusion: The results suggest that practitioners view the guideline development process as credible and useful to guide practice. Whether the stated intention to use the guidelines will actually translate into practice requires further study.

Unlabelled: This evidence-based practice guideline on the use of paclitaxel (Taxol) or docetaxel (Taxotere) as first-line treatment for patients with advanced non-small cell lung cancer who are candidates for palliative first-line chemotherapy is based on a systematic search and review of literature published in full or in abstract form between 1985 and April 2005. Forty-five randomized trials, including 11 abstracts, were reviewed and clinicians in the province of Ontario, Canada, provided feedback on a draft version of the guideline. Two phase III trials detected a statistically significant survival advantage for a taxane (paclitaxel or docetaxel) with best supportive care versus best supportive care alone. Among the nine fully published phase III trials comparing platinum-based chemotherapies, taxane-platinum combinations achieved higher response rates compared with older chemotherapy combinations, although significantly longer survival was observed only for docetaxel-cisplatin compared with vindesine-cisplatin. Response rates and survival were generally not significantly different for taxane-platinum combinations compared with other current chemotherapy combinations, although the toxicity profile of the regimens varied. However, in one large trial, improved tumor response and modest survival and quality of life benefits were associated with docetaxel-cisplatin compared with vinorelbine-cisplatin. No statistically significant survival differences were detected in the three fully published phase III trials comparing a taxane-gemcitabine combination with a taxane-platinum regimen., Recommendations: (i) paclitaxel or docetaxel combined with cisplatin is recommended as one of a number of chemotherapy options for the first-line treatment of advanced non-small cell lung cancer in patients with a good performance status; (ii) carboplatin may be combined with a taxane if a patient is unable or unwilling to take cisplatin; (iii) a taxane-gemcitabine combination may be considered for patients with a contraindication to cisplatin and carboplatin; (iv) no firm recommendation can be made on the optimal dose and schedule of taxane-based chemotherapy; however, commonly used regimens include cisplatin 75 mg/m2 combined with either docetaxel 75 mg/m2 or paclitaxel 135 mg/m2 (24-h infusion) and carboplatin AUC 6 combined with paclitaxel 225 mg/m2 (3-h infusion); (v) a single-agent taxane may be used if combination chemotherapy is considered inappropriate.

Dendrimers are branched, synthetic polymers with layered architectures that show promise in several biomedical applications. By regulating dendrimer synthesis, it is possible to precisely manipulate both their molecular weight and chemical composition, thereby allowing predictable tuning of their biocompatibility and pharmacokinetics. Advances in our understanding of the role of molecular weight and architecture on the in vivo behavior of dendrimers, together with recent progress in the design of biodegradable chemistries, has enabled the application of these branched polymers as anti-viral drugs, tissue repair scaffolds, targeted carriers of chemotherapeutics and optical oxygen sensors. Before such products can reach the market, however, the field must not only address the cost of manufacture and quality control of pharmaceutical-grade materials, but also assess the long-term human and environmental health consequences of dendrimer exposure in vivo.

An efficient, convergent synthesis of the core bicyclo[4.3.1]decane ring system of welwitindolinones is described. Key steps in the synthesis include an intramolecular palladium-catalyzed enolate arylation reaction to create the desired bicyclic skeleton and a Curtius rearrangement to install the bridgehead isocyanate unit. [reaction: see text]

Unlabelled: An evidence summary was developed for the surgical management of adult patients with diffuse or localized malignant pleural mesothelioma. This evidence summary is based on a systematic search and review of the literature published between 1985 and February 2004. Relevant studies were identified, according to pre-determined criteria by the authors and methodologists. No randomized controlled trials comparing pleurectomy (PL) with extrapleural pneumonectomy (EPP) or comparing surgery with an alternative treatment were identified. Four comparative studies, seven non-comparative prospective studies, and 16 retrospective case series were identified that looked at PL, or EPP, or PL and EPP. Trial results were not pooled due to the heterogeneity of the treatments in the trials and the fact that no trials were randomized and none were designed to directly compare different treatments. External feedback was obtained from Ontario clinicians, and the provincial Lung Cancer Disease Site Group approved the review., Conclusions: The role of surgery in the management of malignant pleural mesothelioma cannot be precisely defined as the lack of randomized controlled clinical trials makes it impossible to determine whether the use of EPP or PL improves survival or effectively palliates the symptoms of the disease. Future studies of the role of surgery in the treatment of mesothelioma should include evaluations of quality of life.

A series of thiocholesterol-based cationic lipids (TCL) has been designed and synthesized by the attachment of thiocholesterol to a cationic amine via a disulfide bond. TCL can be incorporated into liposomes and used to package DNA into a lipoplex, thereby protecting it from DNase digestion. DNA is rapidly released from the complex in the presence of low concentrations of reducing agents. The lipoplex mediated efficient transfection activity and had low cytotoxicity. To improve the biocompatibility of the cationic lipoplex, TCL were used as a component in the assembly of a nanolipoparticle (NLP). The particle surface was subsequently modified by disulfide exchange to replace the cationic group with a negatively charged (glutathione) or zwitterionic (cysteine) reducing agent. A cell-binding ligand (TAT peptide, sequence GRKKRRQRRRGYG) was then incorporated onto the particle surface to enhance the particle-cell recognition. The sequentially assembled cell-binding NLP with a zwitterionic surface gave a larger transfection yield than the cationic NLP at all concentrations tested. At low DNA concentrations, the enhancement was 80-fold. The disulfide cationic lipids and the sequential assembly strategy enable one to tailor the surface charge, hydrophilicity, and recognition elements of a nanosized gene carrier. This results in increased gene transfer activity in a biocompatible particle.

We have investigated the role of diameter, charge, and steric shielding on the brain distribution of liposomes infused by convection enhanced delivery (CED) using both radiolabeled and fluorescent-labeled particles. Liposomes of 40 and 80-nm diameter traveled the same distance but penetrated significantly less than a 10-kDa dextran; whereas 200-nm-diameter liposomes penetrated less than 80 nm liposomes. A neutral liposome shielded by polyethylene glycol (PEG; 2 kDa; 10% by mole) penetrated significantly farther than an unshielded liposome. Even when shielded with PEG, positive surface charge (10% by mole) significantly reduced the penetration radius compared to a neutral or negative charged liposome (10% by mole). A mathematical CED model including a term for liposome cell binding was applied to analyze the radius of particle penetration. Neutral liposomes had a binding constant of k=0.0010+/-0.0002 min-1, whereas for positive charged liposomes k increased 50-fold. The binding constant was independently verified using a degradable lipid radiolabel that eliminated from the brain with a 9.9+/-2.0 h half-life, equivalent to the calculated elimination constant k=0.0012+/-0.0002 min-1. During CED, liposomes accumulated in a subpopulation of perivascular cells within the brain. A non-degradable lipid radiolabel showed that lipid components remained within these perivascular brain cells for at least 2 days. To reduce this uptake, 100-fold molar excess of non-labeled liposomes were co-infused with labeled liposomes, which significantly increased liposome penetration. These studies suggest that optimization of therapeutic CED using particles such as drug-loaded liposomes, polymeric nanoparticles, non-viral DNA complexes, and viruses will require a strategy to overcome particle binding and clearance by cells within the CNS.

Vertebrate members of the nuclear receptor NR5A subfamily, which includes steroidogenic factor 1 (SF-1) and liver receptor homolog 1 (LRH-1), regulate crucial aspects of development, endocrine homeostasis, and metabolism. Mouse LRH-1 is believed to be a ligand-independent transcription factor with a large and empty hydrophobic pocket. Here we present structural and biochemical data for three other NR5A members-mouse and human SF-1 and human LRH-1-which reveal that these receptors bind phosphatidyl inositol second messengers and that ligand binding is required for maximal activity. Evolutionary analysis of structure-function relationships across the SF-1/LRH-1 subfamily indicates that ligand binding is the ancestral state of NR5A receptors and was uniquely diminished or altered in the rodent LRH-1 lineage. We propose that phospholipids regulate gene expression by directly binding to NR5A nuclear receptors.

Background: We have studied the effects of the poly(ethylene glycol) (PEG) chain length and acyl chain composition on the pH-sensitivity of acid-labile PEG-diorthoester (POD) lipids. The optimal conditions are described for preparation of DNA plasmid encapsulated POD nanolipoparticles (NLPs) which mediate high gene delivery activity in vitro with moderate cytotoxicity., Methods and Results: A series of POD lipids with various PEG chain lengths (750, 2000, and 5000 Da) or acyl chains (distearoyl 18:0 or dioleoyl 18:1) were incorporated into DNA containing NLPs or model liposomes as a stealth and bioresponsive component. We investigated the collapse kinetics of the POD-stabilized liposomes when the PEG chain length was changed. We optimized a detergent dialysis method to encapsulate plasmid DNA into NLPs prepared from a mixture of the various POD lipids, cationic lipid and phosphatidylethanolamine lipid. A critical concentration (28 mM) of n-octyl-beta-D-glucopyranoside (OG) enabled high encapsulation of DNA plasmid into 100 nm particles with a neutral surface charge. The POD NLPs are stable at pH 8.5 but rapidly collapse (approximately 10 min) into aggregates at pH 5.0. In the detergent solution there is a metastable DNA-lipid intermediate that evolves into a stable NLP if the detergent is removed shortly after adding DNA to the lipid-detergent mixture. The rank order of transfection activity from NLPs containing PEG-lipid was POD 750 > POD 5000 = POD 2000 > non-pH-sensitive PEG-lipid. The particle size stability was in the reverse order. Binding of the NLPs to cells reached a maximum level by 12 hours. The POD NLPs had slightly less transfection activity but considerably lower cytotoxicity than the PEI-DNA polyplex., Conclusions: Of the PEG-orthoester lipids tested, POD 2000 is the better choice for the preparation of sterically stabilized NLPs with a small particle diameter, good stability, low cytotoxicity, and satisfactory transfection activity.

The synthesis of P-aryl-2-phosphabicylco[3.3.0]octane x HBF4 salts 3a and 3c is described. Incorporation of the P-3,5-di-tert-butyl-4-methoxyphenyl group in 3c allows use of a less expensive aryl bromide starting material. Deprotonation of the air-stable salts in situ with triethylamine releases the corresponding phosphines 1a and 1c for use in the kinetic resolution of representative secondary alcohols. The method is convenient for small-scale experiments and affords enantioselectivities s close to the values obtained using the free phosphines 1a and 1b in cases where s is ca. 40 or lower., (Copyright 2004 American Chemical Society)

A systematic review and evaluation of evidence for photodynamic therapy in nonsmall cell lung cancer was undertaken. Two authors selected relevant articles according to predefined criteria. External feedback was obtained from Ontario clinicians and the provincial Lung Cancer Disease Site Group approved the review. The Group concluded that photodynamic therapy may have a role in treating superficial early stage disease or in palliating symptoms in late stage disease. The safety and effectiveness of photodynamic therapy compared with other treatment modalities remains undefined. Serious adverse effects can occur; therefore, the suitability of patients for this treatment should be carefully assessed.

Unlabelled: The Lung Cancer Disease Site Group of Cancer Care Ontario's Program in Evidence-based Care conducted a systematic review of literature published between 1985 and July 2003 and developed an evidence-based clinical practice guideline on postoperative radiotherapy in patients with completely resected pathologic stage II or IIIA non-small cell lung cancer (NSCLC). Forty-four Ontario clinicians reviewed the draft guideline. Evidence included one meta-analysis of individual patient data (from nine randomized controlled trials) and three randomized controlled trials (two including data reported in the meta-analysis) that compared surgery with or without postoperative radiotherapy. The meta-analysis and one trial detected a significant detriment to survival with postoperative radiotherapy. Two trials detected no survival difference. The meta-analysis detected a significant advantage in local recurrence-free survival (time to local recurrence or death) with surgery alone, although two trials detected a significant advantage in rate of local recurrence with postoperative radiotherapy. Subset analyses from the meta-analysis and one trial suggested that postoperative radiotherapy was detrimental to survival mainly in stage II disease; no benefit or detriment was evident for stage III disease., Recommendations: Postoperative radiation therapy following complete resection of stage II non-small cell lung cancer is not recommended. No definitive recommendation can be made for stage IIIA disease.

Unlabelled: An evidence-based practice guideline was developed to identify the optimal combination chemotherapy regimen, schedule of administration, and duration of therapy for the first-line treatment of adults with limited-stage small-cell lung cancer. The guideline is based on a systematic search and review of literature published between 1985 and December 2002. Three reviewers selected studies for inclusion in the guideline according to pre-defined criteria. Fifty randomized controlled trials, five in abstract form, were included in the review, and feedback on a draft version of the guideline was obtained from medical oncologists in the province of Ontario, Canada. The most commonly used regimens in clinical trials are cyclophosphamide-doxorubicin(Adriamycin)-vincristine, and etoposide-cisplatin. No combination chemotherapeutic regimen has been conclusively shown to be superior to either of these regimens. Most studies comparing chemoradiation regimens used sequential rather than concurrent thoracic radiotherapy. When treating for cure with chemoradiation, there is evidence from one randomized controlled trial to support the use of etoposide-cisplatin over an anthracycline-containing regimen. There is conflicting evidence concerning a survival advantage for a regimen that alternates cyclophosphamide-doxorubicin-vincristine with etoposide-cisplatin compared with either regimen alone. If bolus etoposide-cisplatin is the treatment of choice, evidence from one randomized trial suggests that the optimal sequence of administration is cisplatin followed by etoposide. The use of maintenance chemotherapy is not indicated. There is insufficient evidence to support the routine use of dose-intensive regimens outside a clinical trial, to determine the optimal duration of chemotherapy, or to support the routine substitution of carboplatin for cisplatin in combination chemotherapy regimens in this patient population., Recommendations: Etoposide-cisplatin is the preferred chemotherapy regimen for patients with limited-stage small-cell lung cancer when concurrent thoracic radiotherapy is used. It is reasonable to offer the alternation of etoposide-cisplatin with cyclophosphamide-doxorubicin-vincristine, provided the administration of radiotherapy concurrent with an anthracycline is avoided.

The EUropean trial on Reduction Of cardiac events with Perindopril in stable coronary Artery disease (EUROPA) demonstrated that the angiotensin- converting enzyme inhibitor, perindopril, compared with placebo, in patients with established coronary artery disease, reduced cardiovascular endpoints by 20% over a four-year follow-up period. Although the authors of this study claim that the risk reduction was best explained by blockade of the renin-angiotensin-aldosterone system, reference to recent meta-analyses of blood pressure (BP)-lowering trials provides compelling evidence that the benefits observed in the trial could be explained by the 5/2 mmHg BP difference between active and placebo treatments.

The synthesis and evaluation of chiral phosphines 11, 15a, 19a, 24a, and 28a as nucleophilic catalysts for anhydride activation and kinetic resolution of alcohols is described. The relative reactivity follows the order 11a > 11b > 15a > 1 in the monocyclic series, and 24a > 19a > 28ain the bicyclic series, with an overall rate advantage of ca. 2 orders of magnitude for the bicyclic phospholanes over the monocyclic analogues. The increased reactivity of the bicyclic phospholanes for the acylation of alcohols is attributed to conformational effects and ground-state destabilization in a highly associative mechanism. Kinetic resolution data demonstrate promising enantioselectivities for 24a.

The acid-labile poly(ethyleneglycol)-diorthoester-distearoylglycerol lipid (POD), was used with a cationic lipid-phosphatidylethanolamine mixture to prepare stabilized plasmid-lipid nanoparticles (POD SPLP) that could mediate gene transfer in vitro by a pH triggered escape from the endosome. Nanoparticles of 60 nm diameter were prepared at pH 8.5 using a detergent dialysis method. The DNA encapsulation efficiency in the nanoparticles was optimal between 10 and 13 mol % ratio of cationic lipid and at a POD content of 20 mol %. The apparent zeta potential of the nanoparticles at 1 mM salt and pH 7.5 was positive, indicating cationic lipid on the external surface. However, the external layer of the nanoparticles was depleted in the cationic component compared to the starting mole ratio. Low pH sensitivity of the POD SPLP was characterized by a lag phase followed by a rapid collapse; at pH 5.3 the nanoparticles collapsed in 100 min. Nanoparticles prepared from a pH-insensitive PEG-lipid, PEG-distearoylglycerol had similar physicochemical characteristics as the POD SPLP but did not collapse at low pH. The POD SPLP had up to 3 orders of magnitude greater gene transfer activity than did the pH-insensitive nanoparticles. Both the pH-sensitive and pH-insensitive nanoparticles were internalized to a qualitatively similar extent in a punctate pattern into cultured cells within 2 h of incubation with the cells; thus, increased gene transfer of the POD SPLP was due to a more rapid escape from the endosome rather than to greater cell association of these nanoparticles. These results suggest that the pH-sensitive stabilized plasmid-lipid nanoparticles may be a useful component of a synthetic vector for parenterally administered gene therapy.

The mechanism of pH-triggered destabilization of liposomes composed of a polyethyleneglycol-orthoester-distearoylglycerol lipid (POD) and phosphatidyl ethanolamine (PE) has been studied using an ANTS/DPX leakage and a lipid-mixing assay. We developed a kinetic model that relates POD hydrolysis to liposome collapse. This minimum-surface-shielding model describes the kinetics of the pH-triggered release of POD/PE liposomes. In the model, when acid-catalyzed hydrolysis lowers the mole percentage of POD on the liposome surface to a critical level, intervesicular lipid mixing is initiated, resulting in a burst of contents release. Two phases of content leakage are observed: a lag phase and a burst phase. During the lag phase, less than 20% of liposomal contents are released and the leakage begins to accelerate when approaching to the transition point. During the burst phase, the leakage rate is dependent on interbilayer contact. The burst phase occurs when the surface density of the PEG lipid is 2.3 +/- 0.6 mol%, regardless of the pH. Vesicles containing 4 mol% of a pH-insensitive PEG-lipid conjugate and 10% POD did not leak contents or collapse at any pH. These data are consistent with the stalk theory to describe the lamellar-to-inverted hexagonal phase transition and set a lower bound of approximately 16 PE lipids on the external monolayer as the contact site required for lipid mixing between two bilayers.

Intracellular delivery of non-transported therapeutic agents has traditionally been thought possible only for low molecular weight (<500 DA) hydrophobic molecules. Higher molecular weight agents including oligonucleotides, proteins, DNA, liposomes, and nanoparticles do not readily enter the cytoplasm. However, the human immunodeficiency virus (HIV) trans-acting transcriptional activator (TAT) protein enters the cytosol by way of an 11 amino acid cationic peptide (TATp). When this cationic sequence is attached to a variety of small pharmacological agents, including paramagnetic ions[1,2] and proteins,[3-6] they are delivered into cells. Further, TATp modification of large cargo, such as proteins, polymers, and nanoparticles, may enable them to internalize into cells as well. The size limitations for cargo delivered by a single TATp are currently undetermined, but multiple TATp attached to polymers, nanoparticles, liposomes, and phage can definitely mediate their internalization. This process appears to follow an endocytotic or potocytic pathway and does not directly transfer the cargo into the cytoplasm of the cell. Here we review recent publications in which multiple TATp have been attached to and resulted in the successful intracellular delivery of nanoparticles.

[reaction: see text] The kinetic resolution of racemic allylic alcohols 3, 6, and 12--17 has been explored using the PBO catalyst 7 for activation of isobutyric anhydride. Trisubstituted allylic alcohols (12--15; 17) are the best substrates and react with an enantioselectivity of s = 32--82 at -40 degrees C.

An alkyl substitution in the beta-amino acid-containing polyamides 1, 2, and 3 leads to an increase in the population of intramolecularly hydrogen bonded conformations. However, the most stable conformation is not always the same one when the substituent is changed from a methyl group to an isopropyl group. For the beta-amino acid derivatives of succinic acid, a methyl group enhances the formation of a head-to-tail type of folding pattern through an 11-membered ring (2b), but an isopropyl group appears to decrease the enhancement. For beta-amino acid derivatives of glutaric acid, an isopropyl group promotes the formation of a bifurcated conformation (3c). The thermodynamic parameters for the equilibrium between non-hydrogen-bonded states and the head-to-tail type of folding of 2a and 2b are obtained by a van't Hoff analysis of the variable-temperature NMR data, which gives a DeltaH of -1.0 kcal/mol and a DeltaS of -4.7 eu for triamide 2a and a DeltaH of -1.0 kcal/mol and a DeltaS of -3.7 e.u. for triamide 2b, each with a correlation coefficient of better than 0.99. The increased proportion of the intramolecular amide-amide hydrogen bond observed for triamide 2b is entirely due to entropic effects according to this analysis.

ESTABLISHED ANTIHYPERTENSIVE TREATMENT: Previous studies have clearly demonstrated the benefits of antihypertensive therapy, particularly in reducing the incidence of stroke. However, there is still concern that the full potential for reversing coronary heart disease in the hypertensive patient has not been realized by treatment with established agents, the diuretics and the beta-blockers. TRIALS ON NEWER AGENTS: A question that still remains to be answered is whether treatment regimens based on alternative drugs, including calcium channel blocking agents and angiotensin converting enzyme inhibitors, will confer an advantage over older drugs. This question is at last being addressed in long-term morbidity and mortality trials with these newer agents.

Several studies have recently been published which have raised doubts over the long-term safety of calcium channel blockers (CCB). These have included retrospective case control studies in hypertension and meta-analyses of small scale studies in unstable angina and myocardial infarction (MI). Most of the reports were primarily concerned with the use of the short acting dihydropyridine nifedipine. Despite wide media coverage of these reports, the results are by no means irrefutable and, because of the nature of the studies themselves, are open to several criticisms. Calcium channel blockers are currently being evaluated in large-scale, prospective, randomised controlled studies, but results are unlikely to be available within the next few years. Meanwhile, the consensus view seems to be that short acting dihydropyridines should in general be avoided and have no place in the management of unstable angina and post MI. In the setting of stable angina, long acting dihydropyridines should generally be used in conjunction with a beta-blocker. In hypertensive patients, long acting dihydropyridines may be used as alternative antihypertensive agents in patients in whom the first line agents (diuretics and beta-blockers) are poorly tolerated, contra-indicated or ineffective.

Normal human serum was found to contain a heat-stable protein which promoted the binding of granulocytes to timothy grass pollen (granulocyte/pollen-binding protein [GPBP]). GPBP was purified by gel filtration, anion exchange, and affinity chromatography. Virtually all of the granulocyte/pollen-binding activity was associated with a beta-1-protein having a molecular mass of approximately 77,000 D and an isoelectric point of between 5.5 and 6.1. By immunoelectrophoresis and sodium dodecyl sulfate-polyacrylamide gel electrophoresis, the protein was identified as transferrin. Monospecific antisera raised against either GPBP or transferrin removed biological activity from GPBP preparations, and GPBP and transferrin gave lines of identity with these two antisera. The apparent heterogeneity in the molecular size and charge of GPBP observed during progressive purification was minimal when GPBP was saturated with ferric ions before the separation procedures. These experiments indicate that granulocyte/pollen binding is a hitherto unrecognized property of transferrin which appears to be unrelated to iron transport and raises the possibility that transferrin might have a physiological role in the removal of certain organic matter.

Human granulocyte/pollen binding protein (GPBP), previously identified as serum transferrin, promoted prolonged firm adherence of neutrophils to Timothy grass pollen. Some characteristics of this adherence reaction are reported. GPBP-induced binding was time-, temperature- and concentration-dependent. Maximal adherence was observed by 2 h and was only slightly decreased at 18 h. The optimal temperature for adherence was 37 degrees C. Concentrations of GPBP as low as 1.25 microgram/ml gave significantly greater binding than the albumin or lactoferrin control. Eosinophils, monocytes and lymphocytes did not appear to participate in GPBP-induced pollen binding reactions at concentrations up to 300 micrograms/ml. In the presence of GPBP, neutrophils adhered to a range of grass, weed and tree pollens. These included timothy, meadow, false oat, rye, giant and short ragweed, plantain, silver birch and ash. GPBP did not facilitate the adherence of granulocytes to inert particles of similar size such as Sephadex beads and agarose. The adherence was Mg++- but not Ca++-dependent and was not inhibited by a monoclonal antibody to the transferrin receptor (OKT9). Transferrin/GPBP did not bind to either neutrophils or pollen grains. A purified commercial transferrin reacted in all respects like GPBP in these pollen binding studies. These observations indicate that GPBP/transferrin-induced adherence of granulocytes to pollen grains is a hitherto unrecognized property of transferrin which appears unrelated to iron transport or the conventional transferrin receptor.

We have previously shown that there were elevations of neutrophil chemotactic activity (NCA) and increases in the percentages of neutrophil and monocyte complement rosettes after exercise-induced asthma (EIA). These observations suggested that leukocyte activation may occur after EIA, possibly as a result of the release of mast-cell-associated mediators. In the present study, we have attempted to establish whether neutrophils and monocytes are functionally altered after EIA as assessed by changes in their cytotoxic capacity. Cytotoxicity was assessed by a direct visual killing assay using opsonized (complement-coated) schistosomula of Schistosoma mansoni as target organisms. Neutrophils and mononuclear cells obtained from 8 patients after exercise-induced asthma (EIA+ve) had increased cytotoxicity for opsonized schistosomula for as long as 60 min after exercise. These changes were preceded by elevations in the concentrations of serum high molecular weight NCA (which were maximal at 10 min after exercise). In asthmatic patients who did not develop exercise-induced asthma (EIA-ve), no significant increases in neutrophil or mononuclear cell killing of schistosomula, or serum NCA concentrations, were observed. There was a highly significant correlation (p less than 0.001) between the reduction in FEV1 and the increases in neutrophil cytotoxicity. In 5 EIA+ve patients, administration of disodium cromoglycate (cromolyn) prior to the exercise task inhibited both the enhancement in neutrophil and mononuclear cell cytotoxicity, as well as the elevations in circulating NCA and the reductions in FEV1.(ABSTRACT TRUNCATED AT 250 WORDS)

Autosomal recessive inheritance of juvenile cataract is described amongst several related sibships of Lehrerleut Hutterites. The main features of the cataract include onset between three and seven years of age; rapid progression to maturity within one to three months; normal intelligence; no systemic associations, and no urinary reducing substances and normal erythrocyte galactokinase activity. Genetic analysis demonstrates the close relationship between parents of affected sibships with a coefficient of inbreeding of affected sibships of 0.0512. Estimates of heterozygote frequency within Lehrerleut Hutterites at 0.128 indicate that if current inbreeding practice continues additional cases can be expected.