Inhibition of MDM2 Promotes Antitumor Responses in p53 Wild-Type Cancer Cells through Their Interaction with the Immune and Stromal Microenvironment

p53 is a transcription factor that plays a central role in guarding the genomic stability of cells through cell-cycle arrest or induction of apoptosis. However, the effects of p53 in antitumor immunity are poorly understood. To investigate the role of p53 in controlling tumor-immune cell cross-talk, we studied murine syngeneic models treated with HDM201, a potent and selective second-generation MDM2 inhibitor. In response to HDM201 treatment, the percentage of dendritic cells increased, including the CD103⁺ antigen cross-presenting subset. Furthermore, HDM201 increased the percentage of Tbet⁺Eomes⁺ CD8⁺ T cells and the CD8⁺/Treg ratio within the tumor. These immunophenotypic changes were eliminated with the knockout of p53 in tumor cells. Enhanced expression of CD80 on tumor cells was observed in vitro and in vivo, which coincided with T-cell-mediated tumor cell killing. Combining HDM201 with PD-1 or PD-L1 blockade increased the number of complete tumor regressions. Responding mice developed durable, antigen-specific memory T cells and rejected subsequent tumor implantation. Importantly, antitumor activity of HDM201 in combination with PD-1/PD-L1 blockade was abrogated in p53-mutated and knockout syngeneic tumor models, indicating the effect of HDM201 on the tumor is required for triggering antitumor immunity. Taken together, these results demonstrate that MDM2 inhibition triggers adaptive immunity, which is further enhanced by blockade of PD-1/PD-L1 pathway, thereby providing a rationale for combining MDM2 inhibitors and checkpoint blocking antibodies in patients with wild-type p53 tumors. SIGNIFICANCE: This study provides a mechanistic rationale for combining checkpoint blockade immunotherapy with MDM2 inhibitors in patients with wild-type p53 tumors.

Combinations with Allosteric SHP2 Inhibitor TNO155 to Block Receptor Tyrosine Kinase Signaling

PURPOSE

SHP2 inhibitors offer an appealing and novel approach to inhibit receptor tyrosine kinase (RTK) signaling, which is the oncogenic driver in many tumors or is frequently feedback activated in response to targeted therapies including RTK inhibitors and MAPK inhibitors. We seek to evaluate the efficacy and synergistic mechanisms of combinations with a novel SHP2 inhibitor, TNO155, to inform their clinical development.

EXPERIMENTAL DESIGN

The combinations of TNO155 with EGFR inhibitors (EGFRi), BRAFi, KRAS^G12Ci, CDK4/6i, and anti-programmed cell death-1 (PD-1) antibody were tested in appropriate cancer models in vitro and in vivo, and their effects on downstream signaling were examined.

RESULTS

In EGFR-mutant lung cancer models, combination benefit of TNO155 and the EGFRi nazartinib was observed, coincident with sustained ERK inhibition. In BRAF^V600E colorectal cancer models, TNO155 synergized with BRAF plus MEK inhibitors by blocking ERK feedback activation by different RTKs. In KRAS^G12C cancer cells, TNO155 effectively blocked the feedback activation of wild-type KRAS or other RAS isoforms induced by KRAS^G12Ci and greatly enhanced efficacy. In addition, TNO155 and the CDK4/6 inhibitor ribociclib showed combination benefit in a large panel of lung and colorectal cancer patient-derived xenografts, including those with KRAS mutations. Finally, TNO155 effectively inhibited RAS activation by colony-stimulating factor 1 receptor, which is critical for the maturation of immunosuppressive tumor-associated macrophages, and showed combination activity with anti-PD-1 antibody.

CONCLUSIONS

Our findings suggest TNO155 is an effective agent for blocking both tumor-promoting and immune-suppressive RTK signaling in RTK- and MAPK-driven cancers and their tumor microenvironment. Our data provide the rationale for evaluating these combinations clinically.

Development of Anti-CD32b Antibodies with Enhanced Fc Function for the Treatment of B and Plasma Cell Malignancies

The sole inhibitory Fcγ receptor CD32b (FcγRIIb) is expressed throughout B and plasma cell development and on their malignant counterparts. CD32b expression on malignant B cells is known to provide a mechanism of resistance to rituximab that can be ameliorated with a CD32b-blocking antibody. CD32b, therefore, represents an attractive tumor antigen for targeting with a monoclonal antibody (mAb). To this end, two anti-CD32b mAbs, NVS32b1 and NVS32b2, were developed. Their complementarity-determining regions (CDR) bind the CD32b Fc binding domain with high specificity and affinity while the Fc region is afucosylated to enhance activation of FcγRIIIa on immune effector cells. The NVS32b mAbs selectively target CD32b⁺ malignant cells and healthy B cells but not myeloid cells. They mediate potent killing of opsonized CD32b⁺ cells via antibody-dependent cellular cytotoxicity and phagocytosis (ADCC and ADCP) as well as complement-dependent cytotoxicity (CDC). In addition, NVS32b CDRs block the CD32b Fc-binding domain, thereby minimizing CD32b-mediated resistance to therapeutic mAbs including rituximab, obinutuzumab, and daratumumab. NVS32b mAbs demonstrate robust antitumor activity against CD32b⁺ xenografts in vivo and immunomodulatory activity including recruitment of macrophages to the tumor and enhancement of dendritic cell maturation in response to immune complexes. Finally, the activity of NVS32b mAbs on CD32b⁺ primary malignant B and plasma cells was confirmed using samples from patients with B-cell chronic lymphocytic leukemia (CLL) and multiple myeloma. The findings indicate the promising potential of NVS32b mAbs as a single agent or in combination with other mAb therapeutics for patients with CD32b⁺ malignant cells.

A Proof of Concept for Biomarker-Guided Targeted Therapy against Ovarian Cancer Based on Patient-Derived Tumor Xenografts

Advanced ovarian cancers are a leading cause of cancer-related death in women and are currently treated with surgery and chemotherapy. This standard of care is often temporarily successful but exhibits a high rate of relapse, after which, treatment options are few. Here we investigate whether biomarker-guided use of multiple targeted therapies, including small molecules and antibody-drug conjugates, is a viable alternative. A panel of patient-derived ovarian cancer xenografts (PDX), similar in genetics and chemotherapy responsiveness to human tumors, was exposed to 21 monotherapies and combination therapies. Three monotherapies and one combination were found to be active in different subsets of PDX. Analysis of gene expression data identified biomarkers associated with responsiveness to each of the three targeted therapies, none of which directly inhibits an oncogenic driver. While no single treatment had as high a response rate as chemotherapy, nearly 90% of PDXs were eligible for and responded to at least one biomarker-guided treatment, including tumors resistant to standard chemotherapy. The distribution of biomarker positivity in The Cancer Genome Atlas data suggests the potential for a similar precision approach in human patients. SIGNIFICANCE: This study exploits a panel of patient-derived xenografts to demonstrate that most ovarian tumors can be matched to effective biomarker-guided treatments.

Distinct Transcriptional Programming Drive Response to MAPK Inhibition in BRAF V600-Mutant Melanoma Patient-Derived Xenografts

Inhibitors targeting BRAF and its downstream kinase MEK produce robust response in patients with advanced BRAF ^V600-mutant melanoma. However, the duration and depth of response vary significantly between patients; therefore, predicting response a priori remains a significant challenge. Here, we utilized the Novartis collection of patient-derived xenografts to characterize transcriptional alterations elicited by BRAF and MEK inhibitors in vivo, in an effort to identify mechanisms governing differential response to MAPK inhibition. We show that the expression of an MITF-high, "epithelial-like" transcriptional program is associated with reduced sensitivity and adaptive response to BRAF and MEK inhibitor treatment. On the other hand, xenograft models that express an MAPK-driven "mesenchymal-like" transcriptional program are preferentially sensitive to MAPK inhibition. These gene-expression programs are somewhat similar to the MITF-high and -low phenotypes described in cancer cell lines, but demonstrate an inverse relationship with drug response. This suggests a discrepancy between in vitro and in vivo experimental systems that warrants future investigations. Finally, BRAF ^V600-mutant melanoma relies on either MAPK or alternative pathways for survival under BRAF and MEK inhibition in vivo, which in turn predicts their response to further pathway suppression using a combination of BRAF, MEK, and ERK inhibitors. Our findings highlight the intertumor heterogeneity in BRAF ^V600-mutant melanoma, and the need for precision medicine strategies to target this aggressive cancer.

Using PDX for Preclinical Cancer Drug Discovery: The Evolving Field

The ability to create patient derived xenografts (PDXs) has evolved considerably from the breakthrough of the development of immune compromised mice. How researchers in drug discovery have utilized PDX of certain cancer types has also changed from traditionally selecting a few models to profile a drug, to opting to assess inter-tumor response heterogeneity by screening across a broad range of tumor models, and subsequently to enable clinical stratification strategies. As with all models and methodologies, imperfections with this approach are apparent, and our understanding of the fidelity of these models continues to expand. To date though, they are still viewed as one of the most faithful modeling systems in oncology. Currently, there are many efforts ongoing to increase the utility and translatability of PDXs, including introducing a human immune component to enable immunotherapy studies.

The metabolic function of cyclin D3-CDK6 kinase in cancer cell survival

D-type cyclins (D1, D2 and D3) and their associated cyclin-dependent kinases (CDK4 and CDK6) are components of the core cell cycle machinery that drives cell proliferation. Inhibitors of CDK4 and CDK6 are currently being tested in clinical trials for patients with several cancer types, with promising results. Here, using human cancer cells and patient-derived xenografts in mice, we show that the cyclin D3-CDK6 kinase phosphorylates and inhibits the catalytic activity of two key enzymes in the glycolytic pathway, 6-phosphofructokinase and pyruvate kinase M2. This re-directs the glycolytic intermediates into the pentose phosphate (PPP) and serine pathways. Inhibition of cyclin D3-CDK6 in tumour cells reduces flow through the PPP and serine pathways, thereby depleting the antioxidants NADPH and glutathione. This, in turn, increases the levels of reactive oxygen species and causes apoptosis of tumour cells. The pro-survival function of cyclin D-associated kinase operates in tumours expressing high levels of cyclin D3-CDK6 complexes. We propose that measuring the levels of cyclin D3-CDK6 in human cancers might help to identify tumour subsets that undergo cell death and tumour regression upon inhibition of CDK4 and CDK6. Cyclin D3-CDK6, through its ability to link cell cycle and cell metabolism, represents a particularly powerful oncoprotein that affects cancer cells at several levels, and this property can be exploited for anti-cancer therapy.

Combined ALK and MDM2 inhibition increases antitumor activity and overcomes resistance in human ALK mutant neuroblastoma cell lines and xenograft models

The efficacy of ALK inhibitors in patients with ALK-mutant neuroblastoma is limited, highlighting the need to improve their effectiveness in these patients. To this end, we sought to develop a combination strategy to enhance the antitumor activity of ALK inhibitor monotherapy in human neuroblastoma cell lines and xenograft models expressing activated ALK. Herein, we report that combined inhibition of ALK and MDM2 induced a complementary set of anti-proliferative and pro-apoptotic proteins. Consequently, this combination treatment synergistically inhibited proliferation of TP53 wild-type neuroblastoma cells harboring ALK amplification or mutations in vitro, and resulted in complete and durable responses in neuroblastoma xenografts derived from these cells. We further demonstrate that concurrent inhibition of MDM2 and ALK was able to overcome ceritinib resistance conferred by MYCN upregulation in vitro and in vivo. Together, combined inhibition of ALK and MDM2 may provide an effective treatment for TP53 wild-type neuroblastoma with ALK aberrations.

DOI:http://dx.doi.org/10.7554/eLife.17137.001

G protein-coupled receptor 34 in ovarian granulosa cells of cattle: changes during follicular development and potential functional implications

Abundance of G protein-coupled receptor 34 (GPR34) mRNA is greater in granulosa cells (GCs) of cystic vs normal follicles of cattle. The present experiments were designed to determine if GPR34 mRNA in granulosa cell [GC] changes during selection and growth of dominant follicles in cattle as well as to investigate the hormonal regulation of GPR34 mRNA in bovine GC in vitro. In Exp. 1, estrous cycles of nonlactating cows were synchronized and then ovariectomized on either day 3-4 or 5-6 after ovulation. GPR34 mRNA abundance in GC was 2.8- to 3.8-fold greater (P < 0.05) in small (1-5 mm) and large (≥8 mm) estrogen-inactive dominant follicles than in large estrogen-active follicles. Also, GPR34 mRNA tended to be greater (P < 0.10) in F2 than F1 follicles on day 3-4 postovulation. In Exp. 2-7, ovaries were collected at an abattoir and GC were isolated and treated in vitro. Expression of GPR34 was increased (P < 0.05) 2.2-fold by IGF1. Tumor necrosis factor (TNF)-α decreased (P < 0.05) the IGF1-induced GPR34 mRNA abundance in small-follicle GC, whereas IGF1 decreased (P < 0.05) GPR34 expression by 45% in large-follicle GC. Treatment of small-follicle GC with either IL-2, prostaglandin E2 or angiogenin decreased (P < 0.05) GPR34 expression, whereas FSH, cortisol, wingless 3A, or hedgehog proteins did not affect (P > 0.10) GPR34 expression. In Exp. 6 and 7, 2 presumed ligands of GPR34, L-a-lysophosphatidylserine (LPPS) and LPP-ethanolamine, increased (P < 0.05) GC numbers and estradiol production by 2-fold or more in small-follicle GC, and this response was only observed in IGF1-treated GC. In conclusion, GPR34 is a developmentally and hormonally regulated gene in GC, and its presumed ligands enhance IGF1-induced proliferation and steroidogenesis of bovine GC.

Current Status of Companion and Complementary Diagnostics: Strategic Considerations for Development and Launch

US Food and Drug Administration (FDA)‐approved diagnostic assays play an increasingly common role in managing patients to prolong lifespan while also enhancing quality of life. Diagnostic assays can be essential for the safe and effective use of therapeutics (companion diagnostic), or may inform on improving the benefit/risk ratio without restricting drug access (complementary diagnostic). This tutorial reviews strategic considerations for drug and assay development resulting in FDA‐approved companion or complementary diagnostic status.

KEAP1 loss modulates sensitivity to kinase targeted therapy in lung cancer

Inhibitors that target the receptor tyrosine kinase (RTK)/Ras/mitogen-activated protein kinase (MAPK) pathway have led to clinical responses in lung and other cancers, but some patients fail to respond and in those that do resistance inevitably occurs (Balak et al., 2006; Kosaka et al., 2006; Rudin et al., 2013; Wagle et al., 2011). To understand intrinsic and acquired resistance to inhibition of MAPK signaling, we performed CRISPR-Cas9 gene deletion screens in the setting of BRAF, MEK, EGFR, and ALK inhibition. Loss of KEAP1, a negative regulator of NFE2L2/NRF2, modulated the response to BRAF, MEK, EGFR, and ALK inhibition in BRAF-, NRAS-, KRAS-, EGFR-, and ALK-mutant lung cancer cells. Treatment with inhibitors targeting the RTK/MAPK pathway increased reactive oxygen species (ROS) in cells with intact KEAP1, and loss of KEAP1 abrogated this increase. In addition, loss of KEAP1 altered cell metabolism to allow cells to proliferate in the absence of MAPK signaling. These observations suggest that alterations in the KEAP1/NRF2 pathway may promote survival in the presence of multiple inhibitors targeting the RTK/Ras/MAPK pathway.

DOI:http://dx.doi.org/10.7554/eLife.18970.001

Phase I study of PF-03446962, a fully human monoclonal antibody against activin receptor-like kinase-1, in patients with hepatocellular carcinoma

BACKGROUND

This expansion cohort of a multicenter, dose-escalation, phase I study (NCT00557856) evaluated safety, tolerability, antitumor activity, pharmacokinetics, and pharmacodynamic effects of the anti-activin receptor-like kinase-1 (ALK-1) monoclonal antibody PF-03446962 in advanced hepatocellular carcinoma (HCC).

PATIENTS AND METHODS

Patients with HCC and disease progression after prior antiangiogenic therapy or intolerance to treatment received PF-03446962 7 mg/kg intravenously biweekly, as recommended in the dose-escalation part of the study.

RESULTS

Twenty-four patients received PF-03446962. The most frequent treatment-related adverse events (AEs) were thrombocytopenia (33.3%), asthenia (29.2), and chills (16.7%). Two patients experienced treatment-related telangiectasia, suggesting an in vivo knockout of ALK-1 function through ALK-1 pathway inhibition. Overall, treatment-related grade 3-4 AEs were reported in eight patients (33.3%). Treatment-related grade 3-4 thrombocytopenia was noted in four patients. No complete or partial responses were reported. Twelve (50%) patients achieved stable disease, which lasted ≥12 weeks in seven (29.2%) patients. The median time to progression was 3 months. Biomarker analyses showed higher mean tumor expression of c-tumor mesenchymal-epithelial transition factor and higher mean serum levels of bone morphogenetic protein-9 in patients with disease control (DC) for ≥12 weeks versus patients with disease progression. Conversely, lower mean serum transforming growth factor-β and vascular endothelial growth factor receptor-3 levels were detected in patients with DC versus patients with progression.

CONCLUSIONS

The observed safety, tolerability, pharmacokinetic profile, and clinical activity support further evaluation of PF-03446962 in patients with HCC and other solid malignancies, as single agent or in combination with other antiangiogenic, chemotherapeutic, or immunotherapeutic agents.

TRIAL REGISTRATION NUMBER

NCT00557856.

Randomized phase II study of axitinib versus placebo plus best supportive care in second-line treatment of advanced hepatocellular carcinoma

BACKGROUND

The efficacy and safety of axitinib, a potent and selective vascular endothelial growth factor receptors 1-3 inhibitor, combined with best supportive care (BSC) was evaluated in a global, randomized, placebo-controlled phase II trial in patients with locally advanced or metastatic hepatocellular carcinoma (HCC).

PATIENTS AND METHODS

Patients with HCC and Child-Pugh Class A who progressed on or were intolerant to one prior antiangiogenic therapy were stratified by tumour invasion (presence/absence of extrahepatic spread and/or vascular invasion) and region (Asian/non-Asian) and randomized (2:1) to axitinib/BSC (starting dose 5 mg twice-daily) or placebo/BSC. The primary end point was overall survival (OS).

RESULTS

The estimated hazard ratio for OS was 0.907 [95% confidence interval (CI) 0.646-1.274; one-sided stratified P = 0.287] for axitinib/BSC (n = 134) versus placebo/BSC (n = 68), with the median (95% CI) of 12.7 (10.2-14.9) versus 9.7 (5.9-11.8) months, respectively. Results of prespecified subgroup analyses in Asian versus non-Asian patients or presence versus absence of tumour invasion were consistent with the overall population. Improvements favouring axitinib/BSC (P < 0.01) were observed in secondary efficacy end point analyses [progression-free survival (PFS), time to tumour progression (TTP), and clinical benefit rate (CBR)], and were retained among Asian patients in the prespecified subgroup analyses. Overall response rate did not differ significantly between treatments and patient-reported outcomes favoured placebo/BSC. Most common all-causality adverse events with axitinib/BSC were diarrhoea (54%), hypertension (54%), and decreased appetite (47%). Baseline serum analyses identified potential new prognostic (interleukin-6, E-selectin, interleukin-8, angiopoietin-2, migration inhibitory factor, and c-MET) or predictive (E-selectin and stromal-derived factor-1) factors for survival.

CONCLUSIONS

Axitinib/BSC did not improve OS over placebo/BSC in the overall population or in stratification subgroups. However, axitinib/BSC resulted in significantly longer PFS and TTP and higher CBR, with acceptable toxicity in patients with advanced HCC.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT01210495.

Randomised phase II study of axitinib or bevacizumab combined with paclitaxel/carboplatin as first-line therapy for patients with advanced non-small-cell lung cancer

BACKGROUND

Efficacy and safety of first-line axitinib/paclitaxel/carboplatin versus bevacizumab/paclitaxel/carboplatin in advanced non-squamous non-small-cell lung cancer (NSCLC) was evaluated.

PATIENTS AND METHODS

Patients with stage IIIB/IV disease stratified by adjuvant therapy and gender were randomised 1 : 1 to axitinib (5 mg twice daily) or bevacizumab [15 mg/kg every 3 weeks (Q3W)], both with paclitaxel (200 mg/m(2) Q3W)/carboplatin (AUC 6 mg min/ml Q3W).

RESULTS

The trial was discontinued after preliminary analysis. Median progression-free survival (primary end point) for axitinib (N = 58) and bevacizumab (N = 60), respectively, was 5.7 and 6.1 months [hazard ratio (HR) 1.09, 95% confidence interval (CI) 0.68-1.76; one-sided stratified P = 0.64]; median overall survival was 10.6 and 13.3 months (HR 1.12, 95% CI 0.74-1.69; one-sided stratified P = 0.70). Objective response rates (95% CI) were 29.3% (18.1-42.7) and 43.3% (30.6-56.8), respectively; risk ratio 0.676 (95% CI 0.41-1.11; one-sided stratified P = 0.94). The most common grade 3/4 adverse events included neutropenia (28% versus 20%), fatigue (14% versus 7%), and hypertension (14% versus 5%). Patient-reported outcomes based on the EORTC QLQ-C30 were similar between arms.

CONCLUSIONS

In patients with advanced non-squamous NSCLC, axitinib/paclitaxel/carboplatin did not improve efficacy versus bevacizumab/paclitaxel/carboplatin, and was less well tolerated.

Effects of fibroblast growth factor 9 on steroidogenesis and control of FGFR2IIIc mRNA in porcine granulosa cells

The objectives of this study were to investigate the effects of fibroblast growth factor 9 (FGF9) on hormone-stimulated porcine granulosa cell proliferation and steroid production and to further elucidate the hormonal and developmental control of FGFR2IIIc gene expression in granulosa cells. Porcine ovaries were collected from a local slaughterhouse and granulosa cells were collected from small to medium (1 to 5 mm) follicles for 5 in vitro studies that were conducted. Cells were cultured for 48 h in 5% fetal calf serum plus 5% porcine serum and then treated with various combinations of FSH, IGF-I, FGF9, Sonic hedgehog (SHH), cortisol, PGE2, and/or wingless-type mouse mammary tumor virus integration site family member 5A (WNT5A) in serum-free medium for an additional 24 or 48 h. Medium was collected for analysis of steroid concentration via RIA, or RNA was collected for gene expression analysis of FGFR2IIIc via quantitative reverse transcription PCR. Fibroblast growth factor 9 stimulated (P < 0.05) IGF-I-induced estradiol production in the presence of FSH and testosterone. However, FGF9 had inconsistent effects on progesterone production, stimulating progesterone production in the presence of FSH and testosterone but inhibiting progesterone production in the presence of IGF-I, FSH, and testosterone. Cell numbers were increased (P < 0.05) by FGF9 in the presence of IGF-I and FSH but not in the presence of FSH and absence of IGF-I. For FGFR2IIIc mRNA studies, granulosa cells were treated with FSH, IGF-I, FGF9, SHH, cortisol, PGE2, or WNT5A. Follicle-stimulating hormone alone had no effect (P > 0.10) whereas IGF-I increased (P < 0.05) FGFR2IIIc mRNA abundance. Cortisol, PGE2, SHH, and WNT5A had no effect (P > 0.10) on FGFR2IIIc gene expression whereas FGF9 in the presence of FSH and IGF-I inhibited (P < 0.05) FGFR2IIIc gene expression. In an in vivo study, granulosa cells from large (7 to 14 mm) follicles had greater (P < 0.05) abundance of FGFR2IIIc mRNA than small (1 to 3 mm) or medium (4 to 6 mm) follicles. In conclusion, IGF-I-induced FGFR2IIIc mRNA may be a mechanism for increased responses to FGF9 in FSH plus IGF-I-treated granulosa cells. Fibroblast growth factor 9 and IGF-I may work together as amplifiers of follicular growth and granulosa cell differentiation by stimulating estradiol production and concomitantly stimulating granulosa cell growth in pigs.

A randomized, double-blind, phase II study of erlotinib with or without sunitinib for the second-line treatment of metastatic non-small-cell lung cancer (NSCLC)

BACKGROUND

Combined inhibition of vascular, platelet-derived, and epidermal growth factor receptor (EGFR) pathways may overcome refractoriness to single agents in platinum-pretreated non-small-cell lung cancer (NSCLC).

PATIENTS AND METHODS

This randomized, double-blind, multicenter, phase II trial evaluated sunitinib 37.5 mg/day plus erlotinib 150 mg/day versus placebo plus erlotinib continuously in 4-week cycles. Eligible patients had histologically confirmed stage IIIB or IV NSCLC previously treated with one or two chemotherapy regimens, including one platinum-based regimen. The primary end point was progression-free survival (PFS) by an independent central review.

RESULTS

One hundred and thirty-two patients were randomly assigned, and the median duration of follow-up was 17.7 months. The median PFS was 2.8 versus 2.0 months for the combination versus erlotinib alone (HR 0.898, P = 0.321). The median overall survival (OS) was 8.2 versus 7.6 months (HR 1.066, P = 0.617). Objective response rates (ORRs) were 4.6% and 3.0%, respectively. Sunitinib plus erlotinib was fairly well tolerated although most treatment-related adverse events (AEs) were more frequent than with erlotinib alone: diarrhea (55% versus 33%), rash (41% versus 30%), fatigue (31% versus 25%), decreased appetite (30% versus 13%), nausea (28% versus 14%), and thrombocytopenia (13% versus 0%).

CONCLUSIONS

The addition of sunitinib to erlotinib did not significantly improve PFS in patients with advanced, platinum-pretreated NSCLC.

Early hospital discharge of infants born to group B streptococci-positive mothers: a decision analysis

OBJECTIVE

To compare the cost-effectiveness of an additional 24-hour inpatient observation for asymptomatic term neonates born to group B streptococcus (GBS)-colonised mothers with adequate intrapartum antibiotic prophylaxis (IAP) after an initial 24-hour in-hospital observation.

DESIGN

Cost-effectiveness analysis from a societal perspective.

SETTING

United States.

POPULATION

Asymptomatic term neonates born to GBS-colonised mothers with IAP after an initial 24-hour in-hospital observation.

METHODS

Monte Carlo simulation for a decision tree model incorporating the following chance events: development of GBS sepsis during the second 24 hours of life, development of GBS sepsis between 48 hours and 7 days of life, prompt versus delayed treatment for sepsis, neonatal mortality and long-term health sequelae.

MAIN OUTCOME MEASURES

Expected cost and quality-adjusted life years (QALYs), Incremental cost-effectiveness ratio (ICER).

RESULTS

Delayed, versus early, hospital discharge results in similar mean expected QALYs, but substantially higher expected cost. The mean difference in QALY is 0.00016 (95% CI 0.00005-0.00040), whereas the mean difference in cost is $1170.96 (95% CI $750.13-1584.32). The ICER is estimated to be $9,771,520.87 per QALY (95% CI $2,573,139.89-24,407,017.82). The proportion of early-onset GBS that develops during the second 24 hours of life, the cost of 24 hours of inpatient observation, and the probability of long-term sequelae following prompt versus delayed treatment play important roles in determining the cost-effectiveness of delayed hospital discharge.

CONCLUSION

Cost-effectiveness analysis suggests that with adequate IAP, discharging asymptomatic term neonates to home after 24 hours is the preferred approach compared with 48 hours inpatient observation.

Delayed reinforcement as an indiscriminable contingency in verbal/nonverbal correspondence training

We investigated the programming of generalization and maintenance of correspondence between verbal and nonverbal behavior in a preschool setting. Four children participated in a series of multiple-baseline designs. In Experiment 1, delayed reinforcement of verbal behavior effectively controlled maintenance of correspondence with previously trained responses and also resulted in generalization of correspondence to one untrained response. As the latter effect was limited, Experiment 2 was a further assessment of the effects of delayed reinforcement of generalization of correspondence to untrained responses, and consistent generalization was shown. Experiment 2 also showed that generalization, if lost, could be recovered through use of "booster training," in which the original contingencies were reinstated for a brief period. Experiment 3 provided replications, with two additional children, of the effects of delayed reinforcement on maintenance of correspondence. Results are discussed in terms of using delayed reinforcement as an indiscriminable contingency.

Chronic renal failure in Jamaican children--an update (2001-2006)

OBJECTIVE

This study evaluated the incidence, epidemiology, aetiology and outcome of chronic renal failure (CRF) in Jamaican children < 12 years old between 2001 and 2006.

METHODS

The required data on all children who fulfilled inclusion criteria were obtained from their medical records at the University Hospital of the West Indies, Bustamante Hospital for Children and from practitioners in hospitals serving children islandwide.

RESULTS

Eighteen new children (72.2% male) presented with CRF. The cumulative annual incidence was 4.61/million child population under age 12 years or 1.14/million total population. Congenital urological disease (44.5%) was the commonest cause of CRF, followed by glomerulonephritis (33.3%). Half of the cases of glomerulonephritis were secondary to HIV-associated nephropathy. Although all children with posterior urethral valves were diagnosed before age 6 months and promptly treated, renal failure present at birth proved irreversible. The mean age at diagnosis of CRF was 6.72 years. Ten children (55.6%) were already in CRF at first presentation with renal disease. Of these, the five with non-urological disease were already in End Stage Renal Disease (ESRD). Mortality was 44.4%. Five children died in ESRD without the benefit of dialysis.

CONCLUSION

The incidence of CRF has increased from the 1985-2000 local study and is mainly due to urological pathology which progresses despite early diagnosis and treatment. Non-urological renal disease is presenting too late for therapeutic intervention. Greater public awareness of symptoms of renal disease is needed. Children's access to dialysis is unpredictable. A paediatric dialysis and transplantation programme is needed.

Molecular analysis of sleep: wake cycles in Drosophila

Sleep is controlled by two major regulatory systems: a circadian system that drives it with a 24-hour periodicity and a home-ostatic system that ensures that adequate amounts of sleep are obtained. We are using the fruit fly Drosophila melanogaster to understand both types of regulation. With respect to circadian control, we have identified molecular mechanisms that are critical for the generation of a clock. Our recent efforts have focused on the analysis of posttranslational mechanisms, specifically the action of different phosphatases that control the phosphorylation and thereby the stability and/or nuclear localization of circadian clock proteins period (PER) and timeless (TIM). Resetting the clock in response to light is also mediated through posttranslational events that target TIM for degradation by the proteasome pathway; a recently identified ubiquitin ligase, jet lag (JET), is required for this response. Our understanding of the homeostatic control of sleep is in its early stages. We have found that mushroom bodies, which are a site of synaptic plasticity in the fly brain, are important for the regulation of sleep. In addition, through analysis of genes expressed under different behavioral states, we have identified some that are up-regulated during sleep deprivation. Thus, the Drosophila model allows the use of cellular and molecular approaches that should ultimately lead to a better understanding of sleep biology.

Self-focused ZnO transducers for ultrasonic biomicroscopy

A simple fabrication technique was developed to produce high frequency (100 MHz) self-focused single element transducers with sputtered zinc oxide (ZnO) crystal films. This technique requires the sputtering of a ZnO film directly onto a curved backing substrate. Transducers were fabricated by sputtering an 18 mum thick ZnO layer on 2 mm diameter aluminum rods with ends shaped and polished to produce a 2 mm focus or f-number equal to one. The aluminum rod served a dual purpose as the backing layer and positive electrode for the resultant transducers. A 4 mum Parylene matching layer was deposited on the transducers after housing and interconnect. This matching layer was used to protect the substrate and condition the transfer of acoustic energy between the ZnO film and the load medium. The pulse-echo response for a representative transducer was centered at 101 MHz with a -6 dB bandwidth of 49%. The measured two way insertion loss was 44 dB. A tungsten wire phantom and an adult zebrafish eye were imaged to show the capability of these transducers.

Pharmacokinetics/genotype associations for major cytochrome P450 enzymes in native and first- and third-generation Japanese populations: comparison with Korean, Chinese, and Caucasian populations

Application of foreign clinical data across geographic regions can accelerate drug development. Drug disposition can be variable, and identification of factors influencing responsible pharmacokinetic/pharmacogenomic approaches could facilitate the universal application of foreign data and reduce the total amount of phase III clinical trials evaluating risks in different populations. Our objective was to establish and compare genotype (major cytochrome P450 (CYP) enzymes)/phenotype associations for Japanese (native and first- and third-generation Japanese living abroad), Caucasian, Chinese, and Korean populations using a standard drug panel. The mean metabolic ratios (MRs) for the four ethnic groups were similar except for a lower activity of CYP2D6 in Caucasians and CYP2C19 in Asians. Genotype, not ethnicity, impacted the MR for CYP2C9, CYP2C19, and CYP2D6; neither affected CYP1A2, CYP2E1, and CYP3A4/5 activities. We conclude that equivalent plasma drug concentrations and metabolic profiles can be expected for native Japanese, first- and third-generation Japanese, Koreans, and Chinese for compounds handled through these six CYP enzymes.

Self-focused ZnO transducers for ultrasonic biomicroscopy

A simple fabrication technique was developed to produce high frequency (100 MHz) self-focused single element transducers with sputtered zinc oxide (ZnO) crystal films. This technique requires the sputtering of a ZnO film directly onto a curved backing substrate. Transducers were fabricated by sputtering an 18 μm thick ZnO layer on 2 mm diameter aluminum rods with ends shaped and polished to produce a 2 mm focus or f-number equal to one. The aluminum rod served a dual purpose as the backing layer and positive electrode for the resultant transducers. A 4 μm Parylene matching layer was deposited on the transducers after housing and interconnect. This matching layer was used to protect the substrate and condition the transfer of acoustic energy between the ZnO film and the load medium. The pulse-echo response for a representative transducer was centered at 101 MHz with a -6 dB bandwidth of 49%. The measured two way insertion loss was 44 dB. A tungsten wire phantom and an adult zebrafish eye were imaged to show the capability of these transducers.

Origin and evolution of high throughput screening

This article reviews the origin and evolution of high throughput screening (HTS) through the experience of an individual pharmaceutical company, revealing some of the mysteries of the early stages of drug discovery to the wider pharmacology audience. HTS in this company (Pfizer, Groton, USA) had its origin in natural products screening in 1986, by substituting fermentation broths with dimethyl sulphoxide solutions of synthetic compounds, using 96-well plates and reduced assay volumes of 50-100 microl. A nominal 30 mM source compound concentration provided high microM assay concentrations. Starting at 800 compounds each week, the process reached a steady state of 7200 compounds per week by 1989. Screening in the Applied Biotechnology and Screening Group was centralized with screens operating in lock-step to maximize efficiency. Initial screens were full files run in triplicate. Autoradiography and image analysis were introduced for (125)I receptor ligand screens. Reverse transcriptase (RT) coupled with quantitative PCR and multiplexing addressed several targets in a single assay. By 1992 HTS produced 'hits' as starting matter for approximately 40% of the Discovery portfolio. In 1995, the HTS methodology was expanded to include ADMET targets. ADME targets required each compound to be physically detected leading to the development of automated high throughput LC-MS. In 1996, 90 compounds/week were screened in microsomal, protein binding and serum stability assays. Subsequently, the mutagenic Ames assay was adapted to a 96-well plate liquid assay and novel algorithms permitted automated image analysis of the micronucleus assay. By 1999 ADME HTS was fully integrated into the discovery cycle.

Uptake of fluoride ions by the glass component of glass ionomer cement

OBJECTIVES

The uptake of F(-) ions by glass ionomer cement (GIC) has been extensively studied but the precise location of the F(-) ion in the GIC structure has not been reported. The aim of this study is to use model materials to elucidate the possible locations. GIC consists of residual particles of aluminosilicate glass surrounded by depleted glass in an ionically crosslinked polymeric matrix. This study evaluates uptake by both unreacted glass particles (RAW) and particles acid-treated to produce a depleted glass surface (DEPLETED).

METHOD

Three glasses, previously studied as cements, were tested at the particle size used in GICs. LG30 contained Al, Ca, O, P, and Si; LG26 also contained F and AH2 contained Na as well. To produce depleted surfaces they were immersed in acetic acid washed and dried at room temperature. Test samples (N=5) were immersed in KF solution (900ppm F). Control solutions without glass were used. Both were stored at 37C for 48h. F concentrations were measured using ISE with TISAB IV.

RESULTS

Uptake was Control-test expressed in micromol/g glass. RAW LG30=56 (16); LG26=35(17); AH2=17(31). DEPLETED LG30=285(41); LG26=431(42); AH2=286(50). The levels of F uptake by DEPLETED were comparable to those found with GICs formed with these glasses.

CONCLUSIONS

The glass particles of GIC, and particularly the depleted zones surrounding them, can account for an appreciable amount of the F uptake observed with cements but do not show the same relation between F content and F uptake previously observed with cements.

Ion processes in glass ionomer cements

Ion processes are involved in many aspects of glass-ionomer cements. The ions released from the glass take part in the formation of the cement matrix. Although this process has been investigated, particularly using model cement systems, no study provides a complete matrix composition. Combining results from different studies enables an approximate composition to be derived. The importance of Phosphorous in controlling ion release from the glass surface has been identified in a number of studies. The release of ions from the set cement into water (and other aqueous liquids) has been much reported, particularly for fluoride. Over most of the release periods studied (i.e. from >7 days up to 3 years), release of F ion is related to t1/2 indicating a diffusion-controlled process. Other ions, except possibly Na+ also show this relationship. The amount of cumulative F release whilst maintaining this relationship indicates that more F than is in the matrix is involved. Ion chromatography would probably elucidate the precise form of the ionic species released. Glass-ionomer cements take up ions from solutions in which they are immersed. The levels are much higher than required to produce as internal/external equilibrium. Studies using dynamic SIMS and XPS give some information on ion location and elemental association. It is suggested that ToF SIMS would elucidate these further. Re-release of uptaken ions can vary considerably for different cements and ion species. Surface disruption of glass ionomers is caused by both F ion and monofluorophosphate ion and occurs much more readily in F containing cements than in F free ones. The mechanism of this process has not been elucidated. Analysis of the ions released from the cement as disruption occurs should provide an indication of the site of attack.

Hedgehog and spinal cord injury

The hedgehog (Hh) pathway is a highly conserved signalling cascade involved in many developmental processes, including a key role in morphogenesis of many tissues including the limb bud, lung, gut, hair follicle and the neural tube. Hh role in adult tissue is less well-established, however, it is known that the pathway becomes activated and reutilised in situations of repair and regeneration. In the nervous system, tissue repair appears impeded in that mature neurons undergo their final cell divisions early in life and central axons do not easily regenerate. The Hh pathway has been shown to be activated in response to nerve damage, leading to the hypothesis that enhancing Hh pathway activation in damaged nerve tissue, inducing the repair process, could offer a potentially new approach to treating neurodegenerative diseases and dysfunction, including spinal cord injury.

The Photo-Activated Antibacterial Action of Toluidine Blue O in a Collagen Matrix and in Carious Dentine

The main aim of this study was to determine the susceptibility to photo-activated disinfection (PAD) of Streptococcus mutans when the organism was present in a collagen matrix--an environment similar to that which would exist within a carious tooth. In addition, the susceptibility to PAD of bacteria present in carious human teeth was also determined. Light was delivered to the collagen and teeth using a system comprising a 0.8-mm diameter isotropic tip emitting light at 633 +/- 2 nm. A single concentration of TBO (10 microg/ml) was used with both collagen and dentine. Two contact times, 30 and 180 s, were evaluated in intact collagen and additionally, for 180 s only, in collagen partially disrupted by shredding. The effect of energy doses from 1.8 to 14.4 J on the kills attained was assessed by determining the number of surviving viable bacteria. In carious dentine, two contact times, 30 and 60 s and one energy dose, 4.8 J, were used. Antibacterial effects were less than those obtained using planktonic suspensions with a maximum mean log reduction of 1.4 in shredded collagen and dentine. Increasing contact time increased the antibacterial effectiveness in both substrates although this was not always of statistical significance. Shredding the collagen resulted in significantly increased bacterial kills compared to those obtained in intact collagen for the 30-second contact time. The collagen matrix appeared to be a suitable model for carious dentine with advantages of availability and reproducibility. The results of this study have shown that PAD can achieve appreciable kills of oral bacteria, including S. mutans, when the organisms are embedded in a collagen gel or are present in carious teeth.

Glass ionomer cement: evidence pointing to fluorine release in the form of monofluorophosphate in addition to fluoride ion

The fluoride ion released from glass ionomer cements into water is reportedly, in part, complexed with other elements present in the cement. When measured using ion selective electrode potentiometry (ISE) a decomplexant TISAB IV (T) is used to convert all fluoride to F- ion which the ISE can detect. In this study, an additional decomplexing procedure (H) designed to hydrolyse fluorine covalently bonded to phosphorus in the monofluorophosphate (MFP) ion into F- was also used. The soluble products from three glass ionomers were analysed by both techniques (H & T). Five 1 x 10 mm discs were each immersed in 10 ml of de-ionised water. This was changed and 4 ml analysed by T and 4 ml by H at 1, 2, 3, 6, 10, 13, 17, 21, 24, 28, and 31 days. H was greater than T for 161 of the 165 pairs ( chi2=74.7, p=<0.001 ). The total cumulative F release H (in micromol/g cement) at 31 days for AH2 was 122.3, s.d. 30.8; LG26 44.0, s.d. 1.55; LG30 10.0, s.d. 3.15 as compared T results of 100.1, s.d. 31.1; 30.3, s.d. 1.92; 3.7, s.d. 1.36, respectively. In all three cases the H was significantly greater than T (matched pair 't' test with p=0.01 or less). H-T was show to have a very strong associative relationship with t1/2 (R2=0.98 or greater p<0.001 ). Evaluating the ratio of P:F in the cements in comparison with the ratio of additional F measured by H to that measured by T produced a relationship log[(H-T)/T]=0.28 x log[P/F]-0.45 with R2=0.999. It is concluded that glass ionomers release more fluorine than is detected by ISE using TISAB IV. If this F is in the form of MFP this may be released more completely into saliva than F as F-, release of which is substantially reduced by Ca2+, since calcium monofluorophosphate is more soluble than CaF2.

The effect of variable energy input from a novel light source on the photoactivated bactericidal action of toluidine blue O on Streptococcus Mutans

Although the combination of toluidine blue O (TBO) dye and laser light at a wavelength of 633 nm has a bactericidal effect, light from laboratory lasers can only be directed externally at a bacterial colony or suspension. In this study a novel delivery system guided the laser light to an 800-micrometer diameter spherical tip (an isotropic tip) from which light radiated producing a uniform sphere of light within the colony or suspension. The system was highly effective in killing TBO-treated Streptococcus mutans NCTC 10449 in stirred planktonic suspension, killing at least 10(9 )cfu/ml. Antibacterial action increased as the delivered energy dose increased. Energy doses of 1.8 J or more produced 100% kills and log reductions of 8-10 cfu/ml. Neither TBO dye nor light alone had a significant antibacterial effect under the experimental conditions used. The existence of a threshold energy, i.e. a minimum energy required before bactericidal action occurred, could not be demonstrated.

Identification of a small molecule inhibitor of the hedgehog signaling pathway: effects on basal cell carcinoma-like lesions

The link between basal cell carcinoma (BCC) and aberrant activation of the Hedgehog (Hh) signaling pathway has been well established in humans and in mouse models. Here we report the development of assays, including two novel in vitro BCC models, which allowed us to screen for Hh inhibitors and test their validity as potential treatments for BCC. We identified a novel small molecule Hh inhibitor (CUR61414) that can block elevated Hh signaling activity resulting from oncogenic mutations in Patched-1. Moreover, CUR61414 can suppress proliferation and induce apoptosis of basaloid nests in the BCC model systems, whereas having no effect on normal skin cells. These findings directly demonstrate that the use of Hh inhibitors could be a valid therapeutic approach for treating BCC.

Primary cultures of prostate cells and their ability to activate carcinogens

Differences in the incidence of prostate cancer (CaP) amongst different migrant populations point to causative agents of dietary and/or environmental origin. Prostate tissues were obtained following transurethral resection of the prostate (TURP) or radical retropubic prostatectomy. After surgery, TURP-derived or tumour-adjacent tissue fragments were minced in warm PFMR-4A medium (37 degrees C) and suspensions pipetted into collagen-coated petri dishes. Non-adherent material was removed by washing with fresh medium after 12 h. Adhered cells subsequently reacted positively with monoclonal antibodies to prostate specific antigen (PSA). PSA was also detected in the medium. The genotoxicities of the chemical carcinogens 2-amino-1-methyl-6-phenylimidazo[4,5-b] pyridine (PhIP), its N-hydroxy metabolite (N-OH-PhIP) and benzo[a]pyrene (B[a]P) in adherent cell populations from different donors (n=8) were examined. Cells were treated in suspension for 30 min at 37 degrees C in the presence of the DNA repair inhibitors hydroxyurea (HU) and cytosine arabinoside (ara-C). DNA single-strand breaks were detected in cells by the alkaline single cell-gel electrophoresis ('Comet') assay and quantified by measuring comet tail length (CTL) in microm. All three carcinogens induced dose-related increases in CTLs (P<0.0001) in cells from four donors 24 h post-seeding. However, in cells from a further two donors the genotoxic effects of PhIP, N-OH-PhIP and B[a]P were much less apparent after 48 h than after 24 h in culture. After 96 h in culture, cells from these donors appeared to be resistant to the comet-forming activity of the compounds. However, B[a]P-DNA adducts were still measurable by (32)P-postlabelling for up to 14 days following a 24-h exposure to 50 microM B[a]P in adhered cells from another two donors. This study shows that primary cultures of cells derived from the prostate can activate members of two classes of chemical carcinogens. Further development may provide a robust model system in which to investigate the aetiology of CaP.

The effects of adding fluoride compounds to a fluoride-free glass ionomer cement on subsequent fluoride and sodium release

Studies have shown that ions in a glass ionomer matrix are 1-10% of the amounts present in the original glass. To measure more precisely the release from a cement matrix, known amounts of ions were added to LG30 glass which was fluoride and sodium-free. Cement without additions acted as the control. 1.4-1.6% of each of sodium, calcium and aluminum fluorides were added to three portions of control blend. The sodium and fluoride release into deionised water from five discs of each cements blend was measured for 8 months. This represented complete release for sodium but not for fluoride. Traces of fluoride and sodium in the glass produced low but measurable amounts indicating about a third of the fluoride and substantially all sodium present in LG30 was released. The addition of calcium fluoride had no significant effect on sodium or fluoride release and aluminium fluoride minimal effects. Adding sodium fluoride significantly enhanced release of both ions although fluoride release was less than from a glass containing 5% fluoride. Only small proportions of the additions, 2-5% of the fluoride and 13% of sodium, were released. Sodium and fluoride appeared to be released independently. For LG30 cements additives were poor at supplying extra ions.

Hedgehog signaling pathway as a target for therapeutic intervention in basal cell carcinoma

Basal cell carcinomas (BCC) are slow-growing skin tumors that rarely metastasize but frequently recur, most often around the face, head and neck. Currently, surgery is the only treatment practice, which can be painful and leave scars. However, several years ago it was discovered that almost all forms of BCC result from mutations in a signaling pathway controlled by a protein called Hedgehog (Hh). Recently, a novel small-molecule drug candidate, CUR-61414, has been identified that blocks this pathway and could potentially be effective for the treatment of BCC. CUR-61414 was reported to prevent the proliferation and selectively induce the death of the tumor cells, while not harming adjacent normal skin cells in two different models of BCC. These findings directly demonstrate that the use of Hh inhibitors could be a valid novel therapeutic approach for treating BCC.

Chronic renal failure in Jamaican children

In order to document the incidence, aetiology and outcome of chronic renal failure in Jamaican children, paediatric surgeons and hospital based paediatricians island-wide were contacted, and the nephrology records at the island's paediatric nephrology centres searched for data on children < 12-year-old with chronic renal failure diagnosed for the first time between January 1985 and December 2000. Thirty-four children were identified, 21 were male. The cumulative annual incidence of chronic renal failure was 3.2 per million children aged < 12 years. The incidence is likely underestimated, as some children may have been undiagnosed and/or not referred. Glomerulonephritis was the commonest cause of chronic renal failure (50%) followed by obstructive uropathy, reflux nephropathy, renal dysplasia and chronic pyelonephritis (41.2%). Five children (14.7%) had reflux nephropathy (post obstructive in four). Half the children were already in chronic renal failure at time of presentation. Mortality was 65%. In Jamaica, childhood chronic renal failure is due mainly to potentially treatable diseases. Local physicians should be more aware of potentially progressive renal diseases and their prevention. Earlier referral of difficult cases for nephrological consultation is recommended. A paediatric dialysis/transplant programme is needed.

Fractionated stereotactic radiotherapy for acoustic neuromas

BACKGROUND

When compared to radiosurgery, fractionated stereotactic radiotherapy (FSR) for acoustic neuroma (AN) offers escalation of tumor dose (Gy) and potential sparing of auditory and facial nerve functions.

METHOD

Over the past 6.5 years 287 consecutive patients have received FSR for AN. One hundred fifty patients have follow up greater than 1 year and comprise this report. Non-invasive, repeat-fixation mask allowed simulation via spiral CT. Differential collimation and beam weighting achieved conformality. Three distinct schedules for total dose and fractionation were used. For AN<3.0 cm diameter (mean volume 1.5+/-0.2 cc), > or =3.0 and < or =3.9 cm (mean volume 8.7+/-1.0 cc) and > or =4.0 cm (mean volume 28.3 cc (one case) doses of 5 Gy given in 5 consecutive daily fractions (25 Gy total) (131 patient), 10 fractions of 3 Gy (30 Gy total) (18 pts), or 20 fractions of 2 Gy (1 patient) were given. All treatments were prescribed to the 80% isodose and given via the dedicated 10 MeV accelerator.

FINDINGS

The percentage decreases in tumor size were 14+/-1 (range: 0-100), 15+/-3 (range 0-38) and 8 for the 25, 30 and 40 Gy regimens, respectively. No patient had growth of AN or developed facial weakness. Two patients developed transient decrease in facial sensation. Rates of hearing preservation were similar for both the larger and smaller tumors.

INTERPRETATION

Fractionated stereotactic radiotherapy may preserve normal function and control both small and large acoustic neuromas.

Evaluation of the Digene Hybrid Capture II Assay with the Rapid Capture System for detection of Chlamydia trachomatis and Neisseria gonorrhoeae

Screening for chlamydial and gonococcal infection has been strongly recommended for all sexually active women under the age of 26. Advances in the ability to detect infection by nucleic acid detection techniques have improved access to screening methods in routine clinical practices. To meet the increasing demand for testing, a high-throughput system is desirable. We evaluated the performance of the Hybrid Capture 2 CT/GC (HC2) assay with the Digene Rapid Capture System (HC2-RCS). The results of HC2-RCS for endocervical samples from 330 women were compared to those of culture and the COBAS Amplicor PCR. For detection of chlamydial infection, HC2-RCS had a sensitivity and a specificity similar to those of PCR (P > 0.5) and an improved sensitivity compared to that of culture (P = 0.007). For identification of gonococcal infections, all assays performed similarly (P > 0.5). The performance of HC2-RCS was also compared to that of the manual HC2 format (HC2-M) with these samples and with 911 endocervical samples collected previously. The performance of HC2-RCS was equivalent to that of HC2-M; the overall concordance rates for the detection of chlamydia and gonorrhea were 99.7% (kappa = 0.97) and 99.8% (kappa = 0.97), respectively. When the HC2 assay was performed with a semiautomated system application designed for high throughput, it demonstrated high sensitivity and a high specificity for detection of both Chlamydia trachomatis and Neisseria gonorrhoeae.

C-reactive protein is elevated in symptomatic compared with asymptomatic patients with carotid artery disease

OBJECTIVES

to investigate the level of inflammatory markers between symptomatic and asymptomatic carotid stenosis patients.

DESIGN

cross-sectional study.

MATERIALS AND METHODS

a prospective study of 137 consecutive patients, admitted electively for carotid endarterectomy during 1997-2000, was conducted. 125 patients had cerebrovascular symptoms: either stroke (neurological deficit >24 h), Transient ischaemic attack (neurological deficit<24 h) or amaurosis fugax. Twelve patients were asymptomatic. A medical history and a fasting venous blood sample were taken from each patient around 6 weeks before surgery. The plasma concentrations of cholesterol and of inflammatory markers; (high sensitivity C-reactive protein (hs-CRP), sICAM-1, sVCAM-1, sE-selectin) were determined.

RESULTS

the concentration of hs-CRP in the symptomatic group (3.9 mg/L) was significantly higher than in the asymptomatic group (2.1 mg/L; p = 0.04). These concentrations were within normal range (<10 mg/L). sICAM-1, sVCAM-1, sE-selectin and total cholesterol concentrations were not different between the two groups.

CONCLUSION

plasma hs-CRP was elevated in symptomatic compared to asymptomatic patients with carotid artery disease. High sensitivity C-reactive protein has been shown to be of prognostic value in a number of cardiovascular conditions and this study suggests it may be of value to identify patient at high risk of developing neurological deficits.

The glass ionomer cement: the sources of soluble fluoride

This study aimed to investigate certain processes of fluoride production which enable glass ionomer cements to leach fluoride. Two fluoroaluminosilicate glasses, G338 and LG26 were used. The free and total fluoride which could be dissolved from the glasses was measured, before and after acetic acid washing. Both glasses contained appreciable amounts of soluble fluoride prior to any acid treatment. The latter process reduced the amount to some 75% of the original levels. Replacing the customary polymeric acid with propionic acid produced a cement which disintegrated in water allowing the amount of fluoride generated by the cement forming process to be measured. Cement production increased soluble fluoride by a further 3%. Both glasses behaved similarly when undergoing the various processes. G338 produced significantly greater quantities of fluoride, of the order of 10, compared with LG26 although containing only three times the amount of fluoride in the glass formula. A substantial proportion, over half, of the total fluoride was complexed especially after contact with cement and when G338 was used. During the period of the experiment, 21 days, total fluoride release did not seem to depend on the square root of time.

A new, highly fluorescent terpyridine which responds to zinc ions with a large red-shift in emission

A sequence of three metal-catalysed aryl coupling reactions leads to the new ligand 4'-(4-N,N-diphenylaminophenyl)-2,2':6',2"-terpyridine, the intense ICT emission of which undergoes a large red-shift upon binding of zinc ions, providing a unique response over other common metal ions.