The Northern Ireland Public Access Defibrillation (NIPAD) study: effectiveness in urban and rural populations

OBJECTIVE

To assess the impact of mobile automated external defibrillators (AEDs) on out-of-hospital cardiac arrests (OHCAs) in urban and rural populations.

DESIGN

Prospective before and after intervention, population study.

SETTING

Urban and rural areas of 160,000 each. Patients, interventions and

MAIN OUTCOME MEASURES

In 2004-6 the demographics of OHCAs were assessed. In 2005-6 AEDs were deployed (29 urban, 53 rural): 335 urban first responders (FRs) and 493 rural FRs were trained in AED use and dispatched to OHCAs. Call-to-response interval (CRI), resuscitation and survival-to-discharge rates for OHCA were compared.

RESULTS

In 2004 there were 163 urban OHCAs and the emergency medical services (EMS) attended 158 (ventricular fibrillation (VF) 27/158 (17.1%)). In 2005-6 there were 226 OHCAs, EMS attended 216 (VF 30/216 (13.9%)). In 2005-6 FRs were paged to 128 OHCAs (56.6%), FRs attended 88/128 (68.8%): 18/128 (14.1%) reached before the EMS. The best combined FR/EMS mean (SD) CRI in 2005-6 (5 min 56 s (4)) was better than the EMS alone in 2004 (7 min (3); p = 0.002). Survival rate was 5.1% in 2004, 1.4% in 2005-6 (p = NS). In 2004 there were 131 rural OHCAs, EMS attended 121 (VF 19/121 (15.7%)). In 2005-6 there were 122 OHCAs, EMS attended 114 (VF 19/114 (16.7%)). In 2005-6 FRs were paged to 49 OHCAs, FRs attended 42/49 (85.7%): 23/49 (46.9%) reached before the EMS. The best combined FR/EMS mean (SD) CRI in 2005-6 (9 min 22 s (6)) was better than the EMS alone in 2004 (11 min 2 s (6); p = 0.018). Survival rate was 2.5% in 2004, 3.5% in 2005-6 (p = NS).

CONCLUSIONS

Despite improvement in CRI there was no impact on survival (witnessed arrest 32.8%, VF 15.6%).

TRIAL REGISTRATION NUMBER

ISRCTN07286796.

Using plastid genome-scale data to resolve enigmatic relationships among basal angiosperms

Although great progress has been made in clarifying deep-level angiosperm relationships, several early nodes in the angiosperm branch of the Tree of Life have proved difficult to resolve. Perhaps the last great question remaining in basal angiosperm phylogeny involves the branching order among the five major clades of mesangiosperms (Ceratophyllum, Chloranthaceae, eudicots, magnoliids, and monocots). Previous analyses have found no consistent support for relationships among these clades. In an effort to resolve these relationships, we performed phylogenetic analyses of 61 plastid genes ( approximately 42,000 bp) for 45 taxa, including members of all major basal angiosperm lineages. We also report the complete plastid genome sequence of Ceratophyllum demersum. Parsimony analyses of combined and partitioned data sets varied in the placement of several taxa, particularly Ceratophyllum, whereas maximum-likelihood (ML) trees were more topologically stable. Total evidence ML analyses recovered a clade of Chloranthaceae + magnoliids as sister to a well supported clade of monocots + (Ceratophyllum + eudicots). ML bootstrap and Bayesian support values for these relationships were generally high, although approximately unbiased topology tests could not reject several alternative topologies. The extremely short branches separating these five lineages imply a rapid diversification estimated to have occurred between 143.8 +/- 4.8 and 140.3 +/- 4.8 Mya.

Intravitreal injections of GDNF-loaded biodegradable microspheres are neuroprotective in a rat model of glaucoma

PURPOSE

To evaluate the efficacy of intravitreal injection of GDNF-loaded biodegradable microspheres in promoting the survival of retinal ganglion cells (RGCs) and their axons in a rat model of chronically elevated intraocular pressure (IOP).

METHODS

Chronic elevation of IOP was induced in Brown Norway rats through injection of hypertonic saline (1.9 M) into the episcleral veins. After injection, IOP was measured twice a week in rats using topical anesthesia. Poly DL-lactide-co-glycolide (PLGA) microspheres were fabricated using a modified version of the spontaneous emulsification technique. Two and ten percent of volume solutions of microspheres loaded with glial cell line-derived neurotrophic factor (GDNF) were injected into the vitreous cavity of rats with elevated IOP, with injections of blank microspheres and PBS serving as controls. Histological analysis was used to quantify surviving RGCs and axons and provide comparison among different groups. In addition, the thickness of the retinal inner plexiform layer (IPL) and the level of glial fibrillary acidic protein (GFAP) expression within the retina and optic nerve were quantitatively compared.

RESULTS

IOP was significantly increased in eyes with episcleral vein injection over untreated eyes (p<0.001) but did not show a significant difference among groups that received intravitreal injections of GDNF microspheres, blank microspheres, or PBS (p=0.1852). The duration of IOP elevation in this experiment was eight weeks. Expression of GDNF and its receptors localizes to the adult rat RGCs. Ten percent of the GDNF microsphere treatment significantly increased RGC survival and axon survival (p<0.001), reduced the loss of retinal IPL thickness (p<0.001), and decreased glial cell activation in the retina and optic nerve (p<0.001) compared with blank microspheres and PBS. In addition, GDNF microsphere treatment moderately reduced cupping of the optic nerve head.

CONCLUSIONS

Delivery of GDNF via biodegradable microspheres significantly increased the survival of RGCs and their axons, preserved IPL thickness, and decreased retina and optic nerve glial cell activation in an experimental glaucoma model. This study suggests that GDNF delivered by PLGA microspheres may be useful as a neuroprotective tool in the treatment of glaucomatous optic neuropathy.

Diagnostic accuracy and clinical utility of a simplified low cost method of counting CD4 cells with flow cytometry in Malawi: diagnostic accuracy study

OBJECTIVES

To assess the diagnostic accuracy and clinical utility of a simplified low cost method for measuring absolute and percentage CD4 counts with flow cytometry.

DESIGN

A CD4 counting method (Blantyre count) using a CD4 and CD45 antibody combination with reduced blood and reagent volumes. Diagnostic accuracy was assessed by measuring agreement of the index test with two other assays (TruCount and FACSCount). Clinical utility was investigated by comparing CD4 counts with the new assay with WHO clinical staging in patients with HIV.

SETTING

Research laboratories and antiretroviral therapy clinic at a medical school and large government hospital in southern Malawi.

PARTICIPANTS

Assay comparisons were performed on consecutive blood samples sent for CD4 counting from 129 patients with HIV. Comparison of CD4 count with staging was conducted on 253 consecutive new patients attending the antiretroviral therapy clinic.

MAIN OUTCOME MEASURES

Limits of agreement with 95% confidence intervals between index test and reference standards.

RESULTS

The limits of agreement for Blantyre count and TruCount were excellent (cell count -48.9 to 27.0 x10(9)/l for absolute counts in the CD4 range <400x10(9)/l and -2.42% to 2.37% for CD4 percentage). The assay was affordable with reagent costs per test of $0.44 ( pound0.22, euro0.33) for both absolute count and CD4 percentage, and $0.11 for CD4 percentage alone. Of 193 patients with clinical stage I or II disease, who were ineligible for antiretroviral therapy by clinical staging criteria, 73 (38%) had CD4 counts <200x10(9)/l. By contrast, 12 (20%) of 60 patients with stage III or IV disease had CD4 counts >350x10(9)/l.

CONCLUSIONS

This simplified method of counting CD4 cells with flow cytometry has good agreement with established commercial assays, is affordable for routine clinical use in Africa, and could improve clinical decision making in patients with HIV.

A Phase II study of 3-aminopyridine-2-carboxaldehyde thiosemicarbazone (3-AP) and gemcitabine in advanced pancreatic carcinoma. A trial of the Princess Margaret hospital Phase II consortium

3-Aminopyridine-2-carboxaldehyde thiosemicarbazone (3-AP, Triapine, Vion Pharmaceuticals, New Haven, CT) is an inhibitor of the M2 subunit of ribonucleotide reductase (RR). Preclinical testing demonstrates synergy between 3-AP and gemcitabine. Phase I studies of the combination have suggested tolerability and some initial evidence of efficacy. Therefore, a phase II study of gemcitabine plus 3-AP in advanced pancreatic carcinoma was undertaken. In this two-step phase II trial, patients with advanced pancreatic adenocarcinoma who had not received prior chemotherapy for advanced disease were treated with 3-AP 105 mg/m(2) given over 2 h. Four hours after the 3-AP infusion was completed, gemcitabine 1,000 mg/m(2) was given over 30 min. Both drugs were given on days 1, 8 and 15 of a 28-day cycle.Twenty-six patients were enrolled to the study. One patient withdrew consent prior to receiving any treatment and is excluded from all further analyses. Four patients discontinued treatment due to adverse effects. Grade 3/4 hematological adverse events included neutropenia, thrombocytopenia, lymphopenia, leukopenia and anemia and the most frequent non-hematological adverse events were fatigue and pain. No objective responses were observed. Eleven patients had stable disease (SD). In five of these eleven patients, SD lasted for more than 6 months. The median time to progression was 4.1 months and the 6 month progression-free survival rate was 29%. The median survival was 9.0 months with a 1-year survival of 28.0%. The combination of 3-AP and gemcitabine is associated with moderate toxicity in patients with advanced pancreatic cancer. This two-stage trial was stopped after stage I due to lack of antitumour activity. On the basis of this clinical trial, the combination of gemcitabine and 3-AP at this dose and schedule does not warrant further study in this patient population.

Association of relative backpack weight with reported pain, pain sites, medical utilization, and lost school time in children and adolescents

BACKGROUND

There is debate about a 10% versus 15% of body weight cutoff point for safe weight of school backpacks. Estimation of the cutoff may be affected by use of survey methods and failure to assess pain experienced while wearing a backpack. Previous research also suggests that younger students and females are more at risk for developing backpack pain.

METHODS

Five hundred and thirty-one 5th- to 12th-grade Northern California students and their backpacks were weighed. Students were individually interviewed about how often they experienced pain while carrying a backpack, the site of their pain, and if the pain had interfered with school activities or led to medical care.

RESULTS

Data support the use of a 10% of body weight cutoff for safe use of backpacks for all grade levels. Younger students and females are more at risk due to relatively lower body weight while females also carry heavier backpacks than males. Greater relative backpack weight is associated with upper- and mid-back pain reports but not neck or lower back pain; it is also associated with lost school time, lost school sports time, and greater chiropractic utilization.

CONCLUSIONS

The 10% cutoff is recommended along with a variety of practical methods to help schools achieve that goal for middle and high school students.

Differential Recruitment of the Splicing Machinery during Transcription Predicts Genome-Wide Patterns of mRNA Splicing

The splicing machinery associates with genes to facilitate efficient cotranscriptional mRNA processing. We have mapped these associations by genome localization analysis to ascertain how splicing is achieved and regulated on a system-wide scale. Our data show that factors important for intron recognition sample nascent mRNAs and are retained specifically at intron-containing genes via RNA-dependent interactions. Spliceosome assembly proceeds cotranscriptionally but completes posttranscriptionally in most cases. Some intron-containing genes were not bound by the spliceosome, including several developmentally regulated genes. On this basis, we predicted and verified regulated splicing and observed a role for nuclear mRNA surveillance in monitoring those events. Finally, we present evidence that cotranscriptional processing events determine the recruitment of specific mRNA export factors. Broadly, our results provide mechanistic insights into the coordinated regulation of transcription, mRNA processing, and nuclear export in executing complex gene expression programs.

Fabry disease: a morphologic study of 11 cases

Fabry disease is a metabolic disorder caused by the genetic deficiency of alpha-galactosidase A. Deposition of glycosphingolipids in podocytes, endothelial cells, and other cell types leads to formation of myelin-like inclusions, which are the hallmark of the disease. In most untreated males, the disorder progresses to end-stage kidney disease. Fabry disease is rare, and no renal biopsy series focusing on pathologic findings has been published in the past 25 years. We retrieved kidney biopsies diagnosed with Fabry disease from our files, and reviewed clinical data as well as the light and electron microscopy. In total, 11 patients were identified: six male subjects aged 17-43 years and five female subjects aged 30-73 years. On average, male patients presented more than 10 years earlier then female patients. A total of 10 patients had proteinuria, two with the nephrotic syndrome. Four male and three female patients had decreased renal function. Light microscopy showed vacuolization of the podocyte cytoplasm and variable glomerular sclerosis. Older patients and males had more advanced glomerular and interstitial sclerosis, but three of the five female patients also had advanced renal disease. Electron microscopy showed the characteristic myelin-like inclusions most prominently in the podocyte cytoplasm. Seven patients also had podocyte foot process effacement. A second type of deposit, unexpected and conspicuous, was identified in three males, and found to be associated with glomerular basement membrane duplications. These deposits were composed of layered membrane-like material, and therefore morphologically distinct from myelin-like inclusions. They probably represent remnants of damaged endothelial cells.

Phase II study of erlotinib (OSI-774) in patients with metastatic colorectal cancer

Erlotinib (Tarceva™, OSI-774), a potent epidermal growth factor receptor tyrosine kinase inhibitor (EGFR), was evaluated in a phase II study to assess its activity in patients with metastatic colorectal cancer. In all, 38 patients with metastatic colorectal cancer were treated with erlotinib at a continuous daily oral dose of 150 mg. Radiological evaluation was carried out every 8 weeks and tumour biopsies were performed before treatment and on day 8. Of 31 evaluable patients, 19 (61%) had progressive disease and 12 (39%) had stable disease (s.d.). The median time to progression for those patients having s.d. was 123 days (range 108–329 days). The most common adverse events were rash in 34 patients and diarrhoea in 23 patients. Correlative studies were conducted to investigate the effect of erlotinib on downstream signalling. Tumour tissue correlations were based on usable tissue from eight match paired tumour samples pre- and on therapy, and showed a statistically significant decrease in the median intensity of both pEGFR (P=0.008) and phospho-extracellular signal-regulated kinase (ERK) (P=0.008) a week after commencement of treatment. No other statistically significant change in tumour markers was observed. Erlotinib was well tolerated with the most common toxicities being rash and diarrhoea. More than one-third of evaluable patients had s.d. for a minimum of 8 weeks. Correlative studies showed a reduction in phosphorylated EGFR and ERK in tumour tissue post-treatment.

A Tyrosine-sulfated Peptide Derived from the Heavy-chain CDR3 Region of an HIV-1-neutralizing Antibody Binds gp120 and Inhibits HIV-1 Infection

Sulfated tyrosines at the amino terminus of the principal HIV-1 coreceptor CCR5 play a critical role in its ability to bind the HIV-1 envelope glycoprotein gp120 and mediate HIV-1 entry. Human antibodies that recognize the CCR5-binding region of gp120 are also modified by tyrosine sulfation, which is necessary for their ability to neutralize HIV-1. Here we demonstrate that a sulfated peptide derived from the CDR3 region of one of these antibodies, E51, can efficiently bind gp120. Association of this peptide, pE51, with gp120 requires tyrosine sulfation and is enhanced by, but not dependent on, CD4. Alteration of any of four pE51 tyrosines, or alteration of gp120 residues 420, 421, or 422, critical for association with CCR5, prevents gp120 association with pE51. pE51 neutralizes HIV-1 more effectively than peptides based on the CCR5 amino terminus and may be useful as a fusion partner with other protein inhibitors of HIV-1 entry. Our data provide further insight into the association of the CCR5 amino terminus with gp120, show that a conserved, sulfate-binding region of gp120 is accessible to inhibitors in the absence of CD4, and suggest that soluble mimetics of CCR5 can be more effective than previously appreciated.

Rapid and accurate pyrosequencing of angiosperm plastid genomes

BACKGROUND

Plastid genome sequence information is vital to several disciplines in plant biology, including phylogenetics and molecular biology. The past five years have witnessed a dramatic increase in the number of completely sequenced plastid genomes, fuelled largely by advances in conventional Sanger sequencing technology. Here we report a further significant reduction in time and cost for plastid genome sequencing through the successful use of a newly available pyrosequencing platform, the Genome Sequencer 20 (GS 20) System (454 Life Sciences Corporation), to rapidly and accurately sequence the whole plastid genomes of the basal eudicot angiosperms Nandina domestica (Berberidaceae) and Platanus occidentalis (Platanaceae).

RESULTS

More than 99.75% of each plastid genome was simultaneously obtained during two GS 20 sequence runs, to an average depth of coverage of 24.6x in Nandina and 17.3x in Platanus. The Nandina and Platanus plastid genomes shared essentially identical gene complements and possessed the typical angiosperm plastid structure and gene arrangement. To assess the accuracy of the GS 20 sequence, over 45 kilobases of sequence were generated for each genome using conventional sequencing. Overall error rates of 0.043% and 0.031% were observed in GS 20 sequence for Nandina and Platanus, respectively. More than 97% of all observed errors were associated with homopolymer runs, with approximately 60% of all errors associated with homopolymer runs of 5 or more nucleotides and approximately 50% of all errors associated with regions of extensive homopolymer runs. No substitution errors were present in either genome. Error rates were generally higher in the single-copy and noncoding regions of both plastid genomes relative to the inverted repeat and coding regions.

CONCLUSION

Highly accurate and essentially complete sequence information was obtained for the Nandina and Platanus plastid genomes using the GS 20 System. More importantly, the high accuracy observed in the GS 20 plastid genome sequence was generated for a significant reduction in time and cost over traditional shotgun-based genome sequencing techniques, although with approximately half the coverage of previously reported GS 20 de novo genome sequence. The GS 20 should be broadly applicable to angiosperm plastid genome sequencing, and therefore promises to expand the scale of plant genetic and phylogenetic research dramatically.

Patterns of long-distance dispersal in Tiquilia subg. Tiquilia (Boraginaceae): implications for the origins of amphitropical disjuncts and Galapagos Islands endemics

Plant biogeographers have long argued whether plant disjunctions result from vicariance or dispersal. One of the classic patterns of plant disjunction involves New World amphitropical disjuncts, as exemplified by Tiquilia subg. Tiquilia (Boraginaceae). Subgenus Tiquilia forms a heterogeneous group of ~20 species that is amphitropically distributed in the deserts of North and South America, with four taxa endemic to the Galápagos Islands. The current study reconstructs the biogeographic history of subg. Tiquilia in order to explore the origins of New World amphitropical disjunction and of Galápagos endemism. A strongly supported phylogeny of the subgenus is estimated using sequence data from matK, ndhF, rps16, ITS, and waxy. Biogeographic analyses using combined and individual marker data sets reveal a complex history of long-distance dispersal in subg. Tiquilia. Biogeographic reconstructions imply a North American origin of the subgenus and its three major lineages and require at least four long-distance dispersal events to explain its current distribution. The South American taxa of subg. Tiquilia result from three independent and nonsimultaneous colonization events, while the monophyly and continental origins of the Galápagos endemics are unresolved. This study contributes to a growing body of evidence that intercontinental dispersal has been more common than previously realized.

Long-term survival results of a randomized trial comparing gemcitabine/cisplatin and methotrexate/vinblastine/doxorubicin/cisplatin in patients with locally advanced and metastatic bladder cancer

PURPOSE

To compare long-term survival in patients with locally advanced and metastatic transitional cell carcinoma (TCC) of the urothelium treated with gemcitabine plus cisplatin (GC) or methotrexate/vinblastine/doxorubicin/cisplatin (MVAC).

PATIENTS AND METHODS

Efficacy data from a large randomized phase III study of GC versus MVAC were updated. Time-to-event analyses were performed on the observed distributions of overall survival time and progression-free survival.

RESULTS

Four hundred and five patients were randomized, 203 to the GC arm and 202 to the MVAC arm. At the time of this analysis, 347 patients have died (GC 176, MVAC 171). Overall survival was similar in both arms (HR 1.09; 95% confidence interval [CI] 0.88-1.34, P = 0.66) with a median survival of 14.0 months (95% CI 12.3-15.5 months) in the GC, and 15.2 months (95% CI 13.2-17.3 months) in the MVAC arm. The median progression-free survival was 7.7 months with GC (95% CI 6.8-8.8) and 8.3 months with MVAC (95% CI 7.3-9.7) with a HR of 1.09 (95% CI 0.89-1.34). Significant prognostic factors favoring overall survival included performance status (>70), TNM staging (M0 vs. M1), low/normal alkaline phosphatase expression, number of sites of disease <3, and the absence of visceral metastasis. By adjusting for these prognostic factors, the HR was 0.99 for overall survival and 1.01 for progression-free survival.

CONCLUSIONS

Long-term overall and progression-free survival following treatment with GC or MVAC are similar. These results strengthen the role of GC as a standard of care in patients with locally advanced and metastatic transitional-cell carcinoma (TCC).

Demographic and temporal trends in out of hospital sudden cardiac death in Belfast

OBJECTIVE

To determine the epidemiology of out of hospital sudden cardiac death (OHSCD) in Belfast from 1 August 2003 to 31 July 2004.

DESIGN

Prospective examination of out of hospital cardiac arrests by using the Utstein style and necropsy reports. World Health Organization criteria were applied to determine the number of sudden cardiac deaths.

RESULTS

Of 300 OHSCDs, 197 (66%) in men, mean age (SD) 68 (14) years, 234 (78%) occurred at home. The emergency medical services (EMS) attended 279 (93%). Rhythm on EMS arrival was ventricular fibrillation (VF) in 75 (27%). The call to response interval (CRI) was mean (SD) 8 (3) minutes. Among patients attended by the EMS, 9.7% were resuscitated and 7.2% survived to leave hospital alive. The CRI for survivors was mean (SD) 5 (2) minutes and for non-survivors, 8 (3) minutes (p < 0.001). Ninety one (30%) OHSCDs were witnessed; of these 91 patients 48 (53%) had VF on EMS arrival. The survival rate for witnessed VF arrests was 20 of 48 (41.7%): all 20 survivors had VF as the presenting rhythm and CRI < or = 7 minutes. The European age standardised incidence for OHSCD was 122/100,000 (95% confidence interval 111 to 133) for men and 41/100,000 (95% confidence interval 36 to 46) for women.

CONCLUSION

Despite a 37% reduction in heart attack mortality in Ireland over the past 20 years, the incidence of OHSCD in Belfast has not fallen. In this study, 78% of OHSCDs occurred at home.

Molecular evidence for the age, origin, and evolutionary history of the American desert plant genus Tiquilia (Boraginaceae)

Although the deserts of North America are of very recent origin, their characteristic arid-adapted endemic plant lineages have been suggested to be much older. Earlier researchers have hypothesized that the ancestors of many of these modern desert lineages first adapted to aridity in highly localized arid or semi-arid sites as early as the late Cretaceous or early Tertiary, and that these lineages subsequently spread and diversified as global climate became increasingly arid during the Cenozoic. No study has explicitly examined these hypotheses for any North American arid-adapted plant group. The current paper tests these hypotheses using the genus Tiquilia (Boraginaceae), a diverse North American desert plant group. A strongly supported phylogeny of the genus is estimated using combined sequence data from three chloroplast markers (matK, ndhF, and rps16) and two nuclear markers (ITS and waxy). Ages of divergence events within the genus are estimated using penalized likelihood and a molecular clock approach on the ndhF tree for Tiquilia and representative outgroups, including most of the major lineages of Boraginales. The dating analysis suggests that the stem lineage of Tiquilia split from its nearest extant relative in the Paleocene or Eocene ( approximately 59-48 Ma). This was followed by a relatively long period before the first divergence in the crown group near the Eocene/Oligocene boundary ( approximately 33-29 Ma), shortly after the greatest Cenozoic episode of rapid aridification. Divergence of seven major lineages of Tiquilia is dated to the early-to-mid Miocene ( approximately 23-13 Ma). Several major lineages show a marked increase in diversification concomitant with the onset of more widespread semi-arid and then arid conditions beginning in the late Miocene ( approximately 7 Ma). This sequence of divergence events in Tiquilia agrees well with earlier researchers' ideas concerning North American desert flora assembly.

A meta-analysis of two randomised trials of early chemotherapy in asymptomatic metastatic colorectal cancer

This report constitutes a prospectively planned meta-analysis combining two almost identical trials undertaken in Australasia and Canada to study the effect of starting chemotherapy immediately in asymptomatic patients with metastatic colorectal cancer. Patients (n=168) were randomised to receive either immediate or delayed treatment (at onset of predefined symptoms). Australasian patients received either weekly 5-fluorouracil and leucovorin (500 and 20 mg m(-2), respectively) (n=59) or the daily x 5 Mayo Clinic schedule (425 and 20 mg m(-2), respectively) (n=42). Canadian patients were treated with the Mayo schedule (n=67). Otherwise, the two studies were almost identical in design and each used the European Organisation for the Research and Treatment of Cancer (EORTC) QLQ-C30 instrument for measuring quality of life (QoL). Treatment was continued until 6 months had elapsed or disease progression occurred. Low accrual led to trial suspension before the predetermined sample size for either study was reached. Median survival was not significantly better with immediate treatment (median 13.0 vs 11.0 months; hazard ratio, 1.15; 95% confidence interval (CI) 0.79-1.72; P=0.49). There was no statistically significant difference in progression-free survival (time from randomisation until first evidence of progression after chemotherapy, 10.2 vs 10.8 months; hazard ratio, 1.08; 95% CI 0.71-1.64; P=0.73). There was no difference in overall QoL or its individual domains between the two treatment strategies at baseline or at any subsequent time point. Early treatment of asymptomatic patients with metastatic colorectal cancer did not provide a survival benefit or improved QoL compared to withholding treatment until symptoms occurred.

Systemic effects of arctic pollutants in beluga whales indicated by CYP1A1 expression

Cytochrome P450 1A1 (CYP1A1) is induced by exposure to polycyclic aromatic hydrocarbons (PAHs) and planar halogenated aromatic hydrocarbons (PHAHs) such as non-ortho polychlorinated biphenyls (PCBs). In this study, we examined CYP1A1 protein expression immunohistochemically in multiple organs of beluga whales from two locations in the Arctic and from the St. Lawrence estuary. These beluga populations have some of the lowest (Arctic sites) and highest (St. Lawrence estuary) concentrations of PCBs in blubber of all cetaceans. Samples from these populations might be expected to have different contaminant-induced responses, reflecting their different exposure histories. The pattern and extent of CYP1A1 staining in whales from all three locations were similar to those seen in animal models in which CYP1A has been highly induced, indicating a high-level expression in these whales. CYP1A1 induction has been related to toxic effects of PHAHs or PAHs in some species. In St. Lawrence beluga, the high level of CYP1A1 expression coupled with high levels of contaminants (including CYP1A1 substrates, e.g., PAH procarcinogens potentially activated by CYP1A1) indicates that CYP1A1 could be involved in the development of neoplastic lesions seen in the St. Lawrence beluga population. The systemic high-level expression of CYP1A1 in Arctic beluga suggests that effects of PAHs or PHAHs may be expected in Arctic populations, as well. The high-level expression of CYP1A1 in the Arctic beluga suggests that this species is highly sensitive to CYP1A1 induction by aryl hydrocarbon receptor agonists.

SPONDYLITIC CHANGES IN LONG-FINNED PILOT WHALES (GLOBICEPHALA MELAS) STRANDED ON CAPE COD, MASSACHUSETTS, USA, BETWEEN 1982 AND 2000

The primary bone pathology diagnoses recognized in cetacea are osteomyelitis and spondylosis deformans. In this study, we determined the prevalence, type, and severity of vertebral pathology in 52 pilot whales, a mass stranding species that stranded on Cape Cod, Massachusetts, between 1982 and 2000. Eleven whales (21%) had hyperostosis and ossification of tendon insertion points on and between vertebrae, chevron bones, and costovertebral joints, with multiple fused blocks of vertebrae. These lesions are typical of a group of interrelated diseases described in humans as spondyloarthropathies, specifically ankylosing spondylitis, which has not been fully described in cetacea. In severe cases, ankylosing spondylitis in humans can inhibit mobility. If the lesions described here negatively affect the overall health of the whale, these lesions may be a contributing factor in stranding of this highly sociable species.

Multiple-channel scaffolds to promote spinal cord axon regeneration

As molecular, cellular, and tissue-level treatments for spinal cord injury are discovered, it is likely that combinations of such treatments will be necessary to elicit functional recovery in animal models or patients. We describe multiple-channel, biodegradable scaffolds that serve as the basis for a model to investigate simultaneously the effects on axon regeneration of scaffold architecture, transplanted cells, and locally delivered molecular agents. Poly(lactic-co-glycolic acid) (PLGA) with copolymer ratio 85:15 was used for these initial experiments. Injection molding with rapid solvent evaporation resulted in scaffolds with a plurality of distinct channels running parallel along the length of the scaffolds. The feasibility of creating scaffolds with various channel sizes and geometries was demonstrated. Walls separating open channels were found to possess void fractions as high as 89%, with accessible void fractions as high as 90% through connections 220 microm or larger. Scaffolds degraded in vitro over a period of 30 weeks, over which time-sustained delivery of a surrogate drug was observed for 12 weeks. Primary neonatal Schwann cells were distributed in the channels of the scaffold and remained viable in tissue culture for at least 48 h. Schwann-cell containing scaffolds implanted into transected adult rat spinal cords contained regenerating axons at one month post-operation. Axon regeneration was demonstrated by three-dimensional reconstruction of serial histological sections.

Receptor and viral determinants of SARS-coronavirus adaptation to human ACE2

Human angiotensin-converting enzyme 2 (ACE2) is a functional receptor for SARS coronavirus (SARS-CoV). Here we identify the SARS-CoV spike (S)-protein-binding site on ACE2. We also compare S proteins of SARS-CoV isolated during the 2002-2003 SARS outbreak and during the much less severe 2003-2004 outbreak, and from palm civets, a possible source of SARS-CoV found in humans. All three S proteins bound to and utilized palm-civet ACE2 efficiently, but the latter two S proteins utilized human ACE2 markedly less efficiently than did the S protein obtained during the earlier human outbreak. The lower affinity of these S proteins could be complemented by altering specific residues within the S-protein-binding site of human ACE2 to those of civet ACE2, or by altering S-protein residues 479 and 487 to residues conserved during the 2002-2003 outbreak. Collectively, these data describe molecular interactions important to the adaptation of SARS-CoV to human cells, and provide insight into the severity of the 2002-2003 SARS epidemic.

Randomized phase II study of two doses of gefitinib in hormone-refractory prostate cancer: a trial of the National Cancer Institute of Canada-Clinical Trials Group

PURPOSE

Overexpression of the epidermal growth factor receptor has been demonstrated in advanced prostate cancer and is associated with a poor outcome. A multi-institutional, randomized, phase II study was undertaken by the National Cancer Institute of Canada-Clinical Trials Group to evaluate the efficacy and toxicity of two doses of oral gefitinib in patients with minimally symptomatic, hormone-refractory prostate cancer (HRPC).

PATIENTS AND METHODS

Between July and November 2001, 40 patients with HRPC and increasing prostate-specific antigen (PSA) or progression in measurable disease who had not received prior chemotherapy were randomly assigned to 250 mg (n = 19) or 500 mg (n = 21) oral gefitinib daily continuously. The primary end points were PSA response rate and objective measurable response. Functional Assessment of Cancer Therapy Prostate Cancer Subscale (FACT-P) quality-of-life questionnaires were completed at baseline and during treatment.

RESULTS

None of the patients demonstrated a PSA or objective measurable response. Five (14.3%) of 35 assessable patients had stable PSA (one patient at 250 mg and four patients at 500 mg), and five patients (14.3%) had a best response of stable disease (duration, 2.5 to 16.8 months). No significant effect on the rate of increase in PSA was seen. The most common drug-related nonhematologic toxicities observed were grade 1 to 2 diarrhea (250 mg, 65%; 500 mg, 56%), fatigue (250 mg, 29%; 500 mg, 33%), and grade 1 to 2 skin rash (250 mg, 24%; 500 mg, 39%). FACT-P scores decreased during treatment, indicating worsening of symptoms compared with baseline.

CONCLUSION

Gefitinib did not result in any responses in PSA or objective measurable disease at either dose level. Gefitinib has minimal single-agent activity in HRPC.

The G-Quadruplex-Interactive Molecule BRACO-19 Inhibits Tumor Growth, Consistent with Telomere Targeting and Interference with Telomerase Function

Interference with telomerase and telomere maintenance is emerging as an attractive target for anticancer therapies. Ligand-induced stabilization of G-quadruplex formation by the telomeric DNA single-stranded 3' overhang inhibits telomerase from catalyzing telomeric DNA synthesis and from capping telomeric ends. We report here the effects of a 3,6,9-trisubstituted acridine compound, BRACO-19, on telomerase function in vitro and in vivo. The biological activity of BRACO-19 was evaluated in the human uterus carcinoma cell line UXF1138L, which has very short telomeres (2.7 kb). In vitro, nuclear human telomerase reverse transcriptase (hTERT) expression was drastically decreased after 24 hours, induction of cellular senescence and complete cessation of growth was seen after 15 days, paralleled by telomere shortening of ca. 0.4 kb. In vivo, BRACO-19 was highly active as a single agent against early-stage (68 mm(3)) tumors in a s.c. growing xenograft model established from UXF1138L cells, if given chronically at 2 mg per kg per day i.p. BRACO-19 produced growth inhibition of 96% compared with controls accompanied by partial regressions (P < 0.018). Immunostaining of xenograft tissues showed that this response was paralleled by loss of nuclear hTERT protein expression and an increase in atypical mitoses indicative of telomere dysfunction. Cytoplasmic hTERT expression and its colocalization with ubiquitin was observed suggesting that hTERT is bound to ubiquitin and targeted for enhanced degradation upon BRACO-19 treatment. This is in accord with a model of induced displacement of telomerase from the telomere. The in vitro and in vivo data presented here is consistent with the G-quadruplex binding ligand BRACO-19 producing an anticancer effect by inhibiting the capping and catalytic functions of telomerase.

Sulphated tyrosines mediate association of chemokines and Plasmodium vivax Duffy binding protein with the Duffy antigen/receptor for chemokines (DARC)

Plasmodium vivax is one of four Plasmodium species that cause human malaria. P. vivax and a related simian malaria parasite, Plasmodium knowlesi, invade erythrocytes by binding the Duffy antigen/receptor for chemokines (DARC) through their respective Duffy binding proteins. Here we show that tyrosines 30 and 41 of DARC are modified by addition of sulphate groups, and that the sulphated tyrosine 41 is essential for association of the Duffy binding proteins of P. vivax (PvDBP) and P. knowlesi (PkDaBP) with DARC-expressing cells. These sulphated tyrosines also participate in the association of DARC with each of its four known chemokine ligands. Alteration of tyrosine 41 to phenylalanine interferes with MCP-1, RANTES and MGSA association with DARC, but not with that of IL8. In contrast, alteration of tyrosine 30 to phenylalanine interferes with the association of IL8 with DARC. A soluble sulphated amino-terminal domain of DARC, but not one modified to phenylalanine at residue 41, can be used to block the association of PvDBP and PkDaBP with red blood cells, with an IC50 of approximately 5 nM. These data are consistent with a role for tyrosine sulphation in the association of many or most chemokines with their receptors, and identify a key molecular determinant of erythrocyte invasion by P. vivax.

Cumulative sperm whale bone damage and the bends

Diving mosasaurs, plesiosaurs, and humans develop dysbaric osteonecrosis from end-artery nitrogen embolism ("the bends") in certain bones. Sixteen sperm whales from calves to large adults showed a size-related development of osteonecrosis in chevron and rib bone articulations, deltoid crests, and nasal bones. Occurrence in animals from the Pacific and Atlantic oceans over 111 years made a pathophysiological diagnosis of dysbarism most likely. Decompression avoidance therefore may constrain diving behavior. This suggests why some deep-diving mammals show periodic shallow-depth activity and why gas emboli are found in animals driven to surface precipitously by acoustic stressors such as mid-frequency sonar systems.

Consequences of lysine 72 mutation on the phosphorylation and activation state of cAMP-dependent kinase

General strategies to obtain inactive kinases have utilized mutation of key conserved residues in the kinase core, and the equivalent Lys72 in cAMP-dependent kinase has often been used to generate a "dead" kinase. Here, we have analyzed the consequences of this mutation on kinase structure and function. Mutation of Lys72 to histidine (K72H) generated an inactive enzyme, which was unphosphorylated. Treatment with an exogenous kinase (PDK-1) resulted in a mutant that was phosphorylated only at Thr197 and remained inactive but nevertheless capable of binding ATP. Ser338 in K72H cannot be autophosphorylated, nor can it be phosphorylated in an intermolecular process by active wild type C-subunit. The Lys72 mutant, once phosphorylated on Thr197, can bind with high affinity to the RIalpha subunits. Thus a dead kinase can still act as a scaffold for binding substrates and inhibitors; it is only phosphoryl transfer that is defective. Using a potent inhibitor of C-subunit activity, H-89, Escherichia coli-expressed C-subunit was also obtained in its unphosphorylated state. This protein is able to mature into its active form in the presence of PDK-1 and is able to undergo secondary autophosphorylation on Ser338. Unlike the H-89-treated wild type protein, the mutant protein (K72H) cannot undergo the subsequent cis autophosphorylation following phosphorylation at Thr197. Using these two substrates and mammalian-expressed PDK-1, we can elucidate a possible two-step process for the activation of the C-subunit: initial phosphorylation on the activation loop at Thr197 by PDK-1, or a PDK-1-like enzyme, followed by second cis autophosphorylation step at Ser338.

Efficient replication of severe acute respiratory syndrome coronavirus in mouse cells is limited by murine angiotensin-converting enzyme 2

Replication of viruses in species other than their natural hosts is frequently limited by entry and postentry barriers. The coronavirus that causes severe acute respiratory syndrome (SARS-CoV) utilizes the receptor angiotensin-converting enzyme 2 (ACE2) to infect cells. Here we compare human, mouse, and rat ACE2 molecules for their ability to serve as receptors for SARS-CoV. We found that, compared to human ACE2, murine ACE2 less efficiently bound the S1 domain of SARS-CoV and supported less-efficient S protein-mediated infection. Rat ACE2 was even less efficient, at near background levels for both activities. Murine 3T3 cells expressing human ACE2 supported SARS-CoV replication, whereas replication was less than 10% as efficient in the same cells expressing murine ACE2. These data imply that a mouse transgenically expressing human ACE2 may be a useful animal model of SARS.

Retroviruses pseudotyped with the severe acute respiratory syndrome coronavirus spike protein efficiently infect cells expressing angiotensin-converting enzyme 2

Infection of receptor-bearing cells by coronaviruses is mediated by their spike (S) proteins. The coronavirus (SARS-CoV) that causes severe acute respiratory syndrome (SARS) infects cells expressing the receptor angiotensin-converting enzyme 2 (ACE2). Here we show that codon optimization of the SARS-CoV S-protein gene substantially enhanced S-protein expression. We also found that two retroviruses, simian immunodeficiency virus (SIV) and murine leukemia virus, both expressing green fluorescent protein and pseudotyped with SARS-CoV S protein or S-protein variants, efficiently infected HEK293T cells stably expressing ACE2. Infection mediated by an S-protein variant whose cytoplasmic domain had been truncated and altered to include a fragment of the cytoplasmic tail of the human immunodeficiency virus type 1 envelope glycoprotein was, in both cases, substantially more efficient than that mediated by wild-type S protein. Using S-protein-pseudotyped SIV, we found that the enzymatic activity of ACE2 made no contribution to S-protein-mediated infection. Finally, we show that a soluble and catalytically inactive form of ACE2 potently blocked infection by S-protein-pseudotyped retrovirus and by SARS-CoV. These results permit studies of SARS-CoV entry inhibitors without the use of live virus and suggest a candidate therapy for SARS.

Gemcitabine concurrent with continuous infusional 5-fluorouracil in advanced biliary cancers: a review of the Princess Margaret Hospital experience

BACKGROUND

Unresectable biliary tract cancer has a very poor prognosis. A combination of weekly gemcitabine plus continuous infusional 5-fluorouracil (5-FU) (GEM/CVI 5-FU) was evaluated as therapy for this cancer.

PATIENTS AND METHODS

The charts of 27 patients with advanced biliary tract adenocarcinoma treated with GEM/CVI 5-FU at the Princess Margaret Hospital were evaluated for response, survival and toxicity. The treatment consisted of a 30-min infusion of gemcitabine at 900 mg/m(2) on days 1, 8 and 15 of a 28-day cycle plus 5-FU given via a peripherally inserted central line at 200 mg/m(2)/day continuously for 21 days, every 28 days.

RESULTS

Objective responses were observed in nine patients (33%; 95% confidence interval 17% to 54%). An additional eight patients (30%) achieved stable disease for a median of 4 months (range 2.3-11). Median time to progression and overall survival were 3.7 and 5.3 months, respectively. Direct chemotherapy-related toxicity was mild, with only 11% grade > or =3 myelosuppression. Central venous catheter complications were common (26%). There were no treatment-related deaths.

CONCLUSIONS

This study shows that GEM/CVI 5-FU is active and well tolerated in advanced and metastatic biliary tract cancers.

Potent neutralization of severe acute respiratory syndrome (SARS) coronavirus by a human mAb to S1 protein that blocks receptor association

Effective prophylaxis and antiviral therapies are urgently needed in the event of reemergence of the highly contagious and often fatal severe acute respiratory syndrome (SARS) coronavirus (SARS-CoV) infection. We have identified eight recombinant human single-chain variable region fragments (scFvs) against the S1 domain of spike (S) protein of the SARS-CoV from two nonimmune human antibody libraries. One scFv 80R efficiently neutralized SARS-CoV and inhibited syncytia formation between cells expressing the S protein and those expressing the SARS-CoV receptor angiotensin-converting enzyme 2 (ACE2). Mapping of the 80R epitope showed it is located within the N-terminal 261-672 amino acids of S protein and is not glycosylation-dependent. 80R scFv competed with soluble ACE2 for association with the S1 domain and bound S1 with high affinity (equilibrium dissociation constant, Kd=32.3 nM). A human IgG1 form of 80R bound S1 with a 20-fold higher affinity of 1.59 nM comparable to that of ACE2 (Kd=1.70 nM), and neutralized virus 20-fold more efficiently than the 80R scFv. These data suggest that the 80R human monoclonal antibody may be a useful viral entry inhibitor for the emergency prophylaxis and treatment of SARS, and that the ACE2-binding site of S1 could be an attractive target for subunit vaccine and drug development.

Animal models of spinal cord injury for evaluation of tissue engineering treatment strategies

Tissue engineering approaches to spinal cord injury (SCI) treatment are attractive because they allow for manipulation of native regeneration processes involved in restoration of the integrity and function of damaged tissue. A clinically relevant spinal cord regeneration animal model requires that the model mimics specific pathologic processes that occur in human SCI. This manuscript discusses issues related to preclinical testing of tissue engineering spinal cord regeneration strategies from a number of perspectives. This discussion includes diverse causes, pathology and functional consequences of human SCI, general and species related considerations, technical and animal care considerations, and data analysis methods.

Structural basis of tyrosine sulfation and VH-gene usage in antibodies that recognize the HIV type 1 coreceptor-binding site on gp120

The conserved surface of the HIV-1 gp120 envelope glycoprotein that binds to the HIV-1 coreceptor is protected from humoral recognition by multiple layers of camouflage. Here we present sequence and genomic analyses for 12 antibodies that pierce these defenses and determine the crystal structures of 5. The data reveal mechanisms and atomic-level details for three unusual immune features: posttranslational mimicry of coreceptor by tyrosine sulfation of antibody, an alternative molecular mechanism controlling such sulfation, and highly selective V(H)-gene usage. When confronted by extraordinary viral defenses, the immune system unveils novel adaptive capabilities, with tyrosine sulfation enhancing the vocabulary of antigen recognition.

Quantitative analysis of interconnectivity of porous biodegradable scaffolds with micro-computed tomography

Pore interconnectivity within scaffolds is an important parameter influencing cell migration and tissue ingrowth needed to promote tissue regeneration. Methods for assessment of interconnectivity are usually qualitative, restricted to two-dimensional images, or are destructive. Microcomputed tomography nondestructively provides three-dimensional (3D) images of intact specimens at high spatial resolutions. We describe an image analysis technique for quantitative assessment of scaffold interconnectivity. Scaffolds were made via a particulate leaching process with 75%, 80%, 85%, and 88% volumetric porogen fractions. Specimens were scanned and resulting 3D, digital images were analyzed with a custom algorithm. A series of virtual, idealized scaffolds were also created for illustration of the algorithm's analysis approach and for its validation. The program calculated accessible void fractions over a range of minimum connection sizes. In real specimens, nearly 100% of the porous volume was connected with outside air for connections greater than or equal to 20 microm in their smallest dimension. In scaffolds made with 75% porogen, the accessible void fraction decreased to 78% if only those connections greater than or equal to 260 microm were considered. The relationship between accessible void fraction and connection size varied as a function of porogen content. The interconnectivity parameter described here may have implications for cell migration and tissue growth into scaffolds.

Angiotensin-converting enzyme 2 is a functional receptor for the SARS coronavirus

Spike (S) proteins of coronaviruses, including the coronavirus that causes severe acute respiratory syndrome (SARS), associate with cellular receptors to mediate infection of their target cells. Here we identify a metallopeptidase, angiotensin-converting enzyme 2 (ACE2), isolated from SARS coronavirus (SARS-CoV)-permissive Vero E6 cells, that efficiently binds the S1 domain of the SARS-CoV S protein. We found that a soluble form of ACE2, but not of the related enzyme ACE1, blocked association of the S1 domain with Vero E6 cells. 293T cells transfected with ACE2, but not those transfected with human immunodeficiency virus-1 receptors, formed multinucleated syncytia with cells expressing S protein. Furthermore, SARS-CoV replicated efficiently on ACE2-transfected but not mock-transfected 293T cells. Finally, anti-ACE2 but not anti-ACE1 antibody blocked viral replication on Vero E6 cells. Together our data indicate that ACE2 is a functional receptor for SARS-CoV.

A 193-amino acid fragment of the SARS coronavirus S protein efficiently binds angiotensin-converting enzyme 2

The coronavirus spike (S) protein mediates infection of receptor-expressing host cells and is a critical target for antiviral neutralizing antibodies. Angiotensin-converting enzyme 2 (ACE2) is a functional receptor for the coronavirus (severe acute respiratory syndrome (SARS)-CoV) that causes SARS. Here we demonstrate that a 193-amino acid fragment of the S protein (residues 318-510) bound ACE2 more efficiently than did the full S1 domain (residues 12-672). Smaller S protein fragments, expressing residues 327-510 or 318-490, did not detectably bind ACE2. A point mutation at aspartic acid 454 abolished association of the full S1 domain and of the 193-residue fragment with ACE2. The 193-residue fragment blocked S protein-mediated infection with an IC(50) of less than 10 nm, whereas the IC(50) of the S1 domain was approximately 50 nm. These data identify an independently folded receptor-binding domain of the SARS-CoV S protein.

Randomized, double-blind, controlled trial of mitoxantrone/prednisone and clodronate versus mitoxantrone/prednisone and placebo in patients with hormone-refractory prostate cancer and pain

PURPOSE

To compare the incidence of palliative response in patients with hormone-resistant prostate cancer (HRPC) treated with mitoxantrone and prednisone (MP) plus clodronate with that of patients treated with MP plus placebo.

MATERIALS AND METHODS

Men with HRPC, bone metastases, and bone pain were randomly assigned to receive clodronate 1,500 mg administered intravenously (IV) or placebo every 3 weeks, in combination with mitoxantrone 12 mg/m2 IV every 3 weeks and prednisone 5 mg orally bid. Patients completed the present pain intensity (PPI) index and Prostate Cancer-Specific Quality-of-Life Instrument at each treatment visit and used a diary to record analgesic use on a daily basis. The primary end point was a reduction to zero or of two points in the PPI or a decrease of 50% in analgesic intake, without increase in either.

RESULTS

The study accrued 209 eligible patients over 44 months. One hundred sixty patients (77%) had mild PPI scores (1 or 2), and 49 (24%) had moderate PPI scores (3 or 4). The primary end point of palliative response was achieved in 46 (46%) of 104 patients on the clodronate arm and in 41 (39%) of 105 patients on the placebo arm (P =.54). The median duration of response, symptomatic disease progression-free survival, overall survival, and overall quality of life were similar between the arms. Subgroup analysis suggested possible benefit in patients with more severe pain.

CONCLUSION

MP provides useful palliation in symptomatic men with HRPC. Clodronate does not increase the rate of palliative response or overall quality of life. Clodronate may be beneficial to patients who have moderate pain, but this requires further confirmation.

Phase II trial of pegylated-liposomal doxorubicin in the treatment of locally advanced unresectable or metastatic transitional cell carcinoma of the urothelial tract

34 patients with advanced unresectable or metastatic urothelial carcinoma who had not received prior chemotherapy for metastatic disease were treated with pegylated-liposomal doxorubicin (PLD) 50 mg/m(2) by a 1-h intravenous infusion (i.v.) every 4 weeks in a multi-institutional phase II trial. 6 of 30 evaluable patients had a partial response to treatment (20%; 95% Confidence Interval (CI), 8-39%) and seven patients had stable disease. Toxicities were primarily non-haematological, but severe palmar-plantar erythrodysesthesia (PPE), lethargy and anorexia were infrequent. Despite a high proportion of patients with poor prognostic features, PLD had clinically significant activity in urothelial cancer in this study. The activity and unique toxicity profile of this drug make it of interest for further study in advanced urothelial cancers in combination with other active agents.

Comparison of gemcitabine versus the matrix metalloproteinase inhibitor BAY 12-9566 in patients with advanced or metastatic adenocarcinoma of the pancreas: a phase III trial of the National Cancer Institute of Canada Clinical Trials Group

PURPOSE

To compare the selective matrix metalloproteinase inhibitor BAY 12-9566 with the nucleoside analog gemcitabine in the treatment of advanced pancreatic cancer.

METHODS

Patients with advanced pancreatic adenocarcinoma who had not previously received chemotherapy were randomly assigned to receive BAY 12-9566 800 mg orally bid continuously or gemcitabine 1,000 mg/m2 administered intravenously on days 1, 8, 15, 22, 29, 36, and 43 for the first 8 weeks, and then days 1, 8, and 15 of each subsequent 28-day cycle. The primary end point was overall survival; secondary end points were progression-free survival, tumor response, quality of life, and clinical benefit. The planned sample size of the study was 350 patients. Two formal interim analyses were planned.

RESULTS

The study was closed to accrual after the second interim analysis on the basis of the recommendation of the National Cancer Institute of Canada Clinical Trials Group Data Safety Monitoring Committee. There were 277 patients enrolled onto the study, 138 in the BAY 12-9566 arm and 139 in the gemcitabine arm. The rates of serious toxicity were low in both arms. The median survival for the BAY 12-9566 arm and the gemcitabine arm was 3.74 months and 6.59 months, respectively (P <.001; stratified log-rank test). The median progression-free survival for the BAY 12-9566 and gemcitabine arms was 1.68 and 3.5 months, respectively (P <.001). Quality-of-life analysis also favored gemcitabine.

CONCLUSION

Gemcitabine is significantly superior to BAY 12-9566 in advanced pancreatic cancer.

Phase I study of cisplatin, irinotecan, and epirubicin administered every 3 weeks in patients with advanced solid tumours

This phase I study was conducted to determine the recommended phase II doses, safety profile, and antitumour activity of a combination regimen of cisplatin, irinotecan, and epirubicin administered every 3 weeks in patients with advanced solid tumours. Cisplatin and epirubicin were given at fixed doses of 50 and 60 mg m(-2), respectively. The irinotecan dose was escalated at 10 mg m(-2) increments from a starting dose level of 70 mg m(-2). Epirubicin, irinotecan, and their metabolites were measured with HPLC methods. In all, 35 patients received 141 courses of treatment. Irinotecan dose was escalated in seven cohorts up to 130 mg m(-2), and then finally de-escalated to 110 mg m(-2). The dose-limiting toxicity was neutropenic fever. Nonhaematologic toxicities included mild to moderate nausea/vomiting, diarrhoea and fatigue. Of 34 patients with evaluable disease, one patient had a complete response and nine patients had partial response, yielding an overall response rate of 29.4%. Pharmacokinetic parameters of epirubicin were not affected by the sequence of drug administration. However, the AUCs of irinotecan and its metabolites were increased significantly when irinotecan and epirubicin were administered concurrently. This combination regimen has promising broad antitumour activity, and will be further evaluated in phase II studies in multiple tumour types.

Phase II study of troxacitabine (BCH-4556) in patients with advanced and/or metastatic renal cell carcinoma: a trial of the National Cancer Institute of Canada-Clinical Trials Group

PURPOSE

A multi-institution phase II study was undertaken by National Cancer Institute of Canada-Clinical Trials Group to evaluate the efficacy and toxicity of intravenous troxacitabine (Troxatyl; Shire Pharmaceuticals Plc, Laval, Quebec, Canada), in patients with renal cell carcinoma.

PATIENTS AND METHODS

Between June 1999 and March 2000, 35 patients (24 male) with a mean age of 60 years who had advanced and/or metastatic disease were treated with troxacitabine given as an intravenous infusion over 30 minutes at a dose of 10 mg/m2 intravenously, once every 3 weeks.

RESULTS

Of the 33 of 35 patients evaluable for response, there were two confirmed partial responses, 21 patients had stable disease (median duration, 4.4 months), and 10 patients had progressive disease. Eight patients remained stable for more than 6 months, of whom six remain free of progression. The most common drug-related nonhematologic toxicities observed were skin rash (77.1%), hand-foot syndrome (68.6%), alopecia (51.4%), fatigue (51.4%), and nausea (57.1%). Out of a total of 145 cycles of treatment, 98 were given without steroid premedication, whereas 47 cycles were given with steroid premedication. Without premedication, skin rash occurred in 37% of cycles compared with 26% when steroids were given prophylactically.

CONCLUSION

Troxacitabine given at a dose of 10 mg/m2 once every 3 weeks was well tolerated in patients with metastatic renal cell cancer, with common toxicities being a moderate to severe granulocytopenia and skin rash. Steroid premedication may reduce the frequency and severity of the skin rash. Our current study suggests that the nucleoside analog troxacitabine may have modest activity against renal cell carcinoma; however, larger studies are required to confirm this.

Structural basis for peptide binding in protein kinase A. Role of glutamic acid 203 and tyrosine 204 in the peptide-positioning loop

For optimal activity the catalytic subunit of cAMP-dependent protein kinase requires a phosphate on Thr-197. This phosphate anchors the activation loop in the proper conformation and contributes to catalytic efficiency by enhancing the phosphoryl transfer rate and increasing the affinity for ATP (1). The crystal structure of the catalytic subunit bound to ATP, and the inhibitor peptide, IP20, highlights the contacts made by the Thr-197 phosphate as well as the role adjacent residues play in contacting the substrate peptide. Glu-203 and Tyr-204 interact with arginines in the consensus sequence of PKA substrates at the P-6 and P-2 positions, respectively. To assess the contribution that each residue makes to peptide recognition, the kinetic properties of three mutant proteins (E203A, Y204A, and Y204F) were monitored using multiple peptide substrates. The canonical peptide substrate, Kemptide, as well as a longer 9-residue peptide and corresponding peptides with alanine substitutions at the P-6 and P-2 positions were used. While the effect of Glu-203 is more localized to the P-6 site, Tyr-204 contributes to global peptide recognition. An aromatic hydrophobic residue is essential for optimal peptide recognition and is conserved throughout the protein kinase family.

Cytochrome P4501A expression, chemical contaminants and histopathology in roach, goby and sturgeon and chemical contaminants in sediments from the Caspian Sea, Lake Balkhash and the Ily River Delta, Kazakhstan

Roach, goby and sturgeon were examined for cytochrome P4501A (CYP1A) expression and histopathology, in relation to contaminant burdens in fish and sediment. Gradients of induction of CYP1A were observed. Roach from the Ural and Ily River Deltas and roach and goby from the two stations nearest the Caspian Sea oil fields displayed higher levels of CYP1A expression in several organs than was observed in fish from further offshore. Great sturgeon and Russian sturgeon showed higher levels of CYP1A expression than was seen in starred sturgeon and gobies in the Ural delta. No fish showed evidence of contaminant-related histopathologies in the organs examined, despite the elevated CYP1A levels. Low levels of polychlorinated biphenyls and elevated levels of inshore and riverine petroleum hydrocarbons from these habitats suggest that this ongoing hydrocarbon exposure, and that from natural sources and long-term oil exploration on the Northeastern Caspian shore, contributed to the CYP1A induction observed.

Phosphorylation of the catalytic subunit of protein kinase A. Autophosphorylation versus phosphorylation by phosphoinositide-dependent kinase-1

The identification of phosphoinositide-dependent kinase-1 (PDK-1) as an activating kinase for members of the AGC family of kinases has led to its implication as the activating kinase for cAMP-dependent protein kinase. It has been established in vitro that PDK-1 can phosphorylate the catalytic (C) subunit (), but the Escherichia coli-expressed C-subunit undergoes autophosphorylation. To assess which of these mechanisms occurs in mammalian cells, a set of mutations was engineered flanking the site of PDK-1 phosphorylation, Thr-197, on the activation segment of the C-subunit. Two distinct requirements appeared for autophosphorylation and phosphorylation by PDK-1. Autophosphorylation was disrupted by mutations that compromised activity (Thr-201 and Gly-200) or altered substrate recognition (Arg-194). Conversely, only residues peripheral to Thr-197 altered PDK-1 phosphorylation, including a potential hydrophobic PDK-1 binding site at the C terminus. To address the in vivo requirements for phosphorylation, select mutant proteins were transfected into COS-7 cells, and their phosphorylation state was assessed with phospho-specific antibodies. The phosphorylation pattern of these mutant proteins indicates that autophosphorylation is not the maturation mechanism in the eukaryotic cell; instead, a heterologous kinase with properties resembling the in vitro characteristics of PDK-1 is responsible for in vivo phosphorylation of PKA.

Biodegradable polymer grafts for surgical repair of the injured spinal cord

PURPOSE

Biodegradable polymers have been used in the surgical repair of peripheral nerves, but their potential for use in the central nervous system has not been exploited adequately. This article discusses concepts related to the engineering of a biodegradable polymer graft for surgical repair of the injured spinal cord and explores the potential means by which such a device might promote axon regeneration and functional recovery after spinal cord injury.

CONCEPT

A biodegradable polymer implant with controlled microarchitecture can be engineered, and its composition can be optimized for implantation in the spinal cord.

RATIONALE

The use of a biodegradable polymer implant has the dual advantages of providing a structural scaffold for axon growth and a conduit for sustained-release delivery of therapeutic agents. As a scaffold, the microarchitecture of the implant can be engineered for optimal axon growth and transplantation of permissive cell types. As a conduit for the delivery of therapeutic agents that may promote axon regeneration, the biodegradable polymer offers an elegant solution to the problems of local delivery and controlled release over time. Thus, a biodegradable polymer graft would theoretically provide an optimal structural, cellular, and molecular framework for the regrowth of axons across a spinal cord lesion and, ultimately, neurological recovery.

CONCLUSION

Biodegradable polymer grafts may have significant therapeutic potential in the surgical repair of the injured spinal cord. Further research should be focused on the bioengineering, characterization, and experimental application of these devices.