Pharmacokinetically guided phase 1 trial of the IGF-1 receptor antagonist RG1507 in children with recurrent or refractory solid tumors

PURPOSE

This pediatric phase I study was designed to identify the doses of RG1507, a monoclonal antibody against the Type 1 Insulin-like Growth Factor Receptor (IGF1R), that achieves exposures equivalent to those achieved in adults at recommended doses.

EXPERIMENTAL DESIGN

Children with relapsed or refractory solid tumors were treated using the same doses and administration schedules of RG1507 (3 and 9 mg/kg/wk, and 16 mg/kg every 3 weeks [q3W]) as those studied in adults. Detailed pharmacokinetic (PK) sampling was performed after the first dose; selected peak and trough levels were subsequently obtained. Target exposures were ≥85% of mean areas under concentration x time curves (AUCs) in adults at doses of 9 mg/kg/wk and 16 mg/kg q3W. A maximum tolerated dose could be identified if dose-limiting toxicities (DLT) occurred.

RESULTS

Thirty-one evaluable patients aged 3-17 years were enrolled at 3 mg/kg/wk (n = 3), 9 mg/kg/wk (n = 18), or 16 mg/kg q3W (n = 10). There were no DLTs. At 9 mg/kg/wk the mean AUC(0-7d) (21,000 μg h/mL) exceeded the target (16,000 μg h/mL). At 16 mg/kg q3W, the mean AUC(021d) (70,000 μg h/mL) exceeded the target (59,400 μg h/mL). Clearance normalized to body weight was age dependent. There were no objective responses. Seven patients had stable disease for >12 weeks, including two patients with osteosarcoma with stable disease for 52+ and 78+ weeks.

CONCLUSIONS

The recommended doses of RG1507 in children with solid tumors are 9 mg/kg/wk and 16 mg/kg q3W. This flexible design is well suited for trials of agents associated with limited toxicity.

Universal hepatitis C screening in genitourinary medicine

Our genitourinary (GU) medicine service currently offers all attendees hepatitis C testing, regardless of risk factors. We carried out a retrospective case-note review of all cases of hepatitis C diagnosed in 2008 to determine whether a significant number of these cases would have been missed if screening was targeted at high-risk groups. Twenty-three cases of hepatitis C were diagnosed from approximately 30,000 screening tests, of which 19 were available for study. In all, 53% (10/19) were polymerase chain reaction-negative resolved infection and 47% (9/19) were chronic active hepatitis. All cases of infection had identifiable risk factors for infection with hepatitis C. We are now changing our guidelines to screen only those with identifiable risk factors.

Characteristics of children enrolled in treatment trials for NF1-related plexiform neurofibromas

OBJECTIVE

To describe the characteristics of children enrolled in treatment trials for neurofibromatosis type 1 (NF1)-related plexiform neurofibroma (PN), PN tumor burden, PN-related complications, and treatment outcomes and to highlight the differences between characteristics of children with NF1 vs children with cancers entered on early phase drug trials.

METHODS

Pre-enrollment characteristics and complications of PN were retrospectively analyzed in a cohort of 59 children with NF1-related PN treated on 1 of 7 clinical trials at the NIH between 1996 and 2007. Outcome was analyzed in a subset of 19 patients enrolled in phase I trials. Comparisons to children with cancer were made from a similar analysis performed recently.

RESULTS

The median age at enrollment was 8 years. The median PN volume was 555 mL. Most patients had no prior chemotherapy or radiation, but nearly half had previous surgery for PN. PN-associated complications and NF1 manifestations were common, including pain (53%), other tumors (18%), and hypertension (8%). Investigational drug therapy was well tolerated. A median of 10 treatment cycles was administered. Patients with NF1-related PN were younger, had better performance score, had less prior therapy, and remained on study longer than cancer patients.

CONCLUSIONS

Children with NF1-related plexiform neurofibroma (PN) enrolled in clinical trials had large tumors with substantial morbidity. Clinical trials in these children provide information about drug tolerance, cumulative toxicity, and pharmacokinetics in a younger population than early phase pediatric cancer trials. This report may aid in the evaluation of the applicability of traditional pediatric cancer trial designs and endpoints for NF1-related PN.

Phase I/II trial of vandetanib in children and adolescents with hereditary medullary thyroid carcinoma

10014

Background: Mutations in the RET protooncogenecause hereditary medullary thyroid carcinoma (MTC) including Multiple Endocrine Neoplasia (MEN) Type 2A, Type 2B and familial MTC. Vandetanib inhibits VEGFR, EGFR, and RET tyrosine kinases and is active in adults with hereditary MTC. Methods: We are conducting a trial of vandetanib in children and adolescents with RET mutations and MTC. Safety is evaluated at each dose level in adolescents (13–18 years) prior to enrolling children (5–12 years). In the absence of dose limiting toxicity (DLT), intrapatient dose escalation is permitted after cycle 2. To assess bone toxicity, growth plate volume is measured using MRI. Response is monitored using tumor measurements (RECIST), serum biomarkers, calcitonin (CTN), and carcinoembryonic antigen (CEA). Results: Five adolescents and 2 children were enrolled at the 100 mg/m2 dose level, 3 adolescents were dose escalated to 150 mg/m2. Six have MEN2B (M918T RET mutation). Median (range) baseline CTN was 12,200 pg/mL (2,300–67,000) and CEA was 104 mcg/L (5–325). Dose limiting diarrhea was observed in 1/5 adolescents at the 100 mg/m2 and 1/3 adolescents escalated to 150 mg/m2. No DLTs were observed in children receiving 100 mg/m2. Non-DLT included elevated TSH (n = 6), rash (n = 5), anorexia (n = 3), diarrhea (n = 2), hypertension (n = 1), and fatigue (n = 1). Median (range) percent change in growth plate volume during therapy was -18% (-44% to + 50%). All patients had linear growth during therapy. Serum CTN and CEA decreased by ≥ 50% in 6/7 and 2/7 patients, respectively. Tumor size decreased in 6/6 patients with M918T RET mutations; 2 achieved RECIST partial response after 6 and 12 cycles. Conclusions: Preliminary results suggest that vandetanib has activity in children and adolescents with MEN2B associated MTC. Vandetanib 100 mg/m2 was well tolerated. Linear growth was not impaired.

[Table: see text]

Phase I study of sorafenib in children with refractory solid tumors: A Children's Oncology Group Phase I Consortium trial

10012

Background: Sorafenib, an oral multitargeted kinase inhibitor, is indicated for treatment of adults with refractory renal cell or hepatocelluar carcinoma. We performed a phase I trial to determine the toxicities, maximum tolerated dose (MTD), pharmacokinetics (PK), and pharmacodynamics (PD) of sorafenib in children with refractory solid tumors. Methods: Sorafenib was administered q12h for 28 consecutive day cycles. Cohorts of 3–12 patients were enrolled at 105, 130, 150, 200, and 250 mg/m2/dose dose levels. Results: 34 eligible pts [16M, median age 14.6 yrs, (range, 5–21)] with osteosarcoma (n = 8), rhabdomyosarcoma (n = 3), other sarcomas (n = 13), hepatoblastoma (n = 3), or other solid tumors (n = 7) received 1–22 cycles (median 2). Grade 3 dose-limiting toxicity (DLT) occurred in 4/6 pts at the starting dose (150 mg/m2) and included hypertension (n = 1), rash/urticaria (n = 1), back pain (n = 1), thrombocytopenia (n = 1) and ALT/AST (n = 1). No DLTs were observed at 105 (n = 6) or 130 (n = 3) mg/m2, and the dose was re-escalated to 150 mg/m2 with modified eligibility criteria (normal ALT) and revised guidelines for grading and management of hypertension. Gr 3 DLTs occurred in 1/6 pts (lipase) at 150 mg/m2 and 2/2 pts (hyponatremia, hand-foot syndrome) at 250 mg/m2. At 200 mg/m2 only 1/6 pts experienced DLT (gr 3 ALT). No objective responses were observed, but 2 pts had tumor shrinkage. Sorafenib AUC did not increase proportionally with dose - the mean AUC0–24h was similar at 150 mg/m2 (28±24 μg · h/mL, n = 9) and 200 mg/m2 (28±17 μg · h/mL, n = 4). Tmax was prolonged and variable (10±11 h, n = 19). Plasma VEGFR (n = 13) decreased from 9.9±1.6 ng/mL at baseline to 8.3±1.7 ng/mL by d 28 (p < 0.001). Conclusions: The MTD of sorafenib in children with solid tumors is 200 mg/m2, similar to the adult recommended dose (400 mg).

No significant financial relationships to disclose.

Domestic violence in a genitourinary medicine setting – an anonymous prevalence study in women

Domestic violence (DV) affects around one in four women in the UK. This study aimed to determine the prevalence of DV and the associations with sociodemographic and sexual behaviour variables in female attendees of an inner-city genitourinary (GU) medicine clinic. In this cross-sectional survey, 177 of 380 women (46.6%) disclosed a history of abuse and 17.4% reported DV in the preceding 12 months. Women with a history of a sexually transmitted infection (STI) were more likely to have experienced DV at some point in their lives (odds ratio [OR] = 2.39; 95% confidence interval [CI]: 1.58–3.63). Logistic regression analysis revealed that being black compared with white, (OR = 1.7; 95% CI: 2.4–12.5) current cohabitation with a partner (OR = 2.24; 95% CI: 1.06–4.75), increasing number of sexual partners in the last year (OR = 1.24; 95% CI: 1.01–1.5) and consumption of illicit drugs (OR = 2.05; 95% CI: 1.02–4.11) were significantly associated with DV in the last 12 months but age, current occupation, history of STIs, age of coitarche and condom use were not. DV was common in this GU medicine clinic population and associated with STIs. We recommend that health practitioners undergo training to increase awareness of the links between partner violence and sexual health problems.

Black and minority ethnic men who have sex with men: a London genitourinary medicine clinic experience

Summary:

The aim was to examine sexual behaviour and rates of sexually transmitted infections (STIs) in black and minority ethnic (BME) men who have sex with men (MSM) attending a London genitourinary medicine clinic. A case-note review of BME MSM (n = 203) attending our service between 1 April 2005 and 31 March 2006 was carried out. BME MSM were those who self-identified as being of Black (Caribbean, African or Other), South Asian (Indian, Pakistani, Bangladeshi or Sri Lankan) and Chinese/South-East Asian (Malaysian, Thai, Filipino, Japanese) ethnicities. Consecutively attending self-identified white British (WB) MSM (n = 203) were used as a comparative group. BME MSM were significantly more likely to report unprotected anal intercourse with casual male partners in the preceding three months (P = 0.0016) and were more likely to report female sexual partners (P = 0.0018). Rectal gonorrhoea was more common in WB MSM (P = 0.02). Numbers of other bacterial STIs and HIV infection were similar in both groups.

The higher reported rates of risk behaviour in BME MSM are of concern and support the need for focussed sexual health promotion.

Molecular analysis of DNA rearrangements in leukemias and non-Hodgkin's lymphomas

Genetic markers for leukemias and lymphomas include chromosomal translocations and antigen-receptor gene rearrangements. Clonal rearrangements of immunoglobulin or T cell receptor (TCR) genes reflect clonal proliferations of lymphocytes, a characteristic feature of lymphoid neoplasia. These rearrangements can be detected as described in this unit by Southern blot hybridization or, in many instances, the polymerase chain reaction (PCR). Specific chromosomal translocations can also serve as markers for clonality, for malignant transformation, and for various defined subtypes of hematopoietic cancers. PCR protocols are described for detection of the two most commonly assayed translocations, t(9;22) of chronic myelogenous leukemia or acute lymphoblastic leukemia, and t(14;18) of follicular lymphomas.

Growth arrest-specific gene 6 expression in human breast cancer

Growth arrest-specific gene 6 (Gas6), identified in 1995, acts as the ligand to the Axl/Tyro3 family of tyrosine kinase receptors and exerts mitogenic activity when bound to these receptors. Overexpression of the Axl/Tyro3 receptor family has been found in breast, ovarian and lung tumours. Gas6 is upregulated 23-fold by progesterone acting through the progesterone receptor B (PRB). Recently, Gas6 has been shown to be a target for overexpression and amplification in breast cancer. Quantitative real-time PCR analysis was used to determine the levels of Gas6 mRNA expression in 49 primary breast carcinomas. Expression of PRB protein was evaluated immunohistochemically with a commercially available PRB antibody. The results showed a positive association between PRB protein and Gas6 mRNA levels (P=0.04). Gas6 correlated positively with a number of favourable prognostic variables including lymph node negativity (P=0.0002), younger age at diagnosis (P=0.04), smaller size of tumours (P=0.02), low Nottingham prognostic index scores (P=0.03) and low nuclear morphology (P=0.03). This study verifies for the first time the association between PRB and Gas6 in breast cancer tissue.

Congenital oesophageal stricture in a Japanese shiba inu

An 11-week-old, female, Japanese shiba inu, weighing 1.3 kg, was presented with a history of intermittent regurgitation since birth. An oesophagram showed a partial obstruction of the caudal cervical oesophagus associated with a narrow, transverse tissue band. Following surgical resection, the regurgitation resolved and the dog attained a normal bodyweight. Histological examination revealed focally hyperplastic epithelium with dense fibrous underlying connective tissue forming the band. The diagnosis was a congenital oesophageal stricture.

Characteristics and outcome of patients (pts) enrolled on phase I trials: A report from the Pediatric Oncology Branch, NCI

9550

Background: Knowledge of the characteristics and outcomes of pts enrolled on pediatric phase I trials may aid in the design of future phase I trials and selection of pts. Methods: Pre-enrollment characteristics and treatment outcomes (toxicity, response, survival) were retrospectively analyzed from pts with refractory solid tumors enrolled in 16 phase I trials with similar eligibility criteria from 1992 to 2005. The relationship between patient characteristics and dose-limiting toxicity (DLT) was evaluated using multivariate analysis. Results: Of 262 pts (62% M, 38% F) eligible for analysis, 147 were on trials of myelosuppressive drugs (MS) and 115 were enrolled on trials of non-MS. 50 pts (19%) participated in =2 separate trials. Median (range) or (frequency) entry characteristics were: age 13.5 yrs (1–24); ECOG performance score 0 (30%), 1 (50%), 2 (19%); prior regimens 2 (0–9); prior stem cell transplant (20%); prior radiation (66%); concomitant medications 1 (0–12); and presence of metastatic disease (65%). 94% of pts were evaluable for the primary trial outcome, and 92% participated in pharmacokinetic (PK) studies. 17% of pts had grade 3 as their highest-grade toxicity. 22% of pts had grade 4 as their highest-grade toxicity, of which 91% were hematological. DLT rate was 18%. 5% of pts came off study due to toxicity, and treatment related death occurred in 0.3%. Age, prior radiation, medications, prior regimens, performance status, gender, transplant history, and drug dose expressed as a fraction of the maximum tolerated dose were included in the multivariate analysis. Only drug dose (OR 14.2, 95% CI 3.0–67.8) and prior radiation (OR 3.4, 95% CI 1.1–10.7) were statistically significantly associated with increased risk of developing DLT after adjusting for all other variables. The median number of cycles was 1 (range 0–31). Complete and partial response rate was 3%, however, 18% of pts had stable disease (received = 3 cycles). The median survival (Kaplan Meier analysis) from time of enrollment was 5 months. Conclusion: Standard phase I eligibility criteria selected a population of pts who tolerated the investigational agents well and >90% were evaluable for the toxicity and PK endpoints. Prior radiation was associated with a greater risk for DLT.

No significant financial relationships to disclose.

The pharmacokinetics (PK) and pharmacodynamics (PD) of ABT-751 in children with recurrent neuroblastoma or other solid tumors

9557

Background: ABT-751 is an orally administered agent that binds to the colchicine site on β-tubulin and blocks microtubule formation. We studied the PK and PD of ABT-751 and its sulfate and glucuronide conjugates in children enrolled on a phase 1 trial in solid tumors and a pilot study in neuroblastoma. Methods: Seventy-two children (2–18 yrs) received ABT-751 on a once, daily × 7d or daily × 21d schedule. Sixty had PK plasma sampling (53 sets analyzed), and 41 had a 24h urine collection after the first dose. Drug concentrations were quantified with a LC/MS/MS assay. Results: Median (range) plasma PK parameters are shown in the table . ABT-751 was rapidly absorbed (Tmax , 2h), and the Cmax and AUC0-8 increased in proportion to dose. The median molar ratio of the sulfate plasma AUC0-8 to glucuronide plasma AUC0-8 was 1.5. The median (range) percent of the administered dose excreted in urine as ABT-751, glucuronide, or sulfate conjugates was 0.09 (0–0.4)%, 10.2 (1.0–38.5)%, and 12.6 (2.3–50.9)%, respectively. The median ABT-751 AUC0-8 was higher in patients with dose-limiting toxicity (DLT) compared to those without DLT on the 7d (118 vs. 74.5 μg·h/mL; P=0.014) and 21d (73.8 vs 49.3 μg·h/mL; P=0.049) schedules. In 28 patients with neuroblastoma, the AUC0-8 did not correlate with time to progression. Apparent clearance (CL/F) did not correlate with age or gender. Conclusions: PK samples were obtained from 83% (60/72) of children enrolled. The ABT-751 AUC0-8 was dose proportional; inter- and intra-patient variability was low. Patients who experienced DLT had higher ABT-751 AUC0-8. The mean CL/F of ABT-751 was similar to that observed in adults (40 mL/min/m2) but did not correlate with age or gender. The sulfate conjugate was the primary metabolite in plasma and urine. Urinary excretion was not a major route of elimination of the parent drug.

[Table: see text]

No significant financial relationships to disclose.

Radiographic tumor response in pediatric patients with newly diagnosed localized (LOC) or metastatic (MET) Ewing’s sarcoma (EWS) following neoadjuvant chemotherapy

20008

Background: Standard treatment for EWS includes vincristine, doxorubicin, cyclophosphamide (VDC) alternating with ifosfamide and etoposide (IE). Using this therapy, overall survival is 70% in patients with LOC EWS and 30% in patients with MET EWS. We compared the radiographic response to VDC and IE in patients with LOC or MET EWS. Methods: We conducted a randomized trial comparing pegfilgrastim to filgrastim in patients treated with VDC (cycles 1, 2, 5, 9, 11, 13) and IE (cycles 3, 4, 6–8, 10, 12, 14). Local control with radiation or surgery was initiated after cycle 5. We assessed radiographic response after VDC (C1,2) and IE (C3,4) using 1-dimensional (RECIST) and 2-dimensional (WHO) criteria. Measurements were performed using MEDx. Results: Twenty-one patients with EWS, median age 20y (6–25y), were enrolled; 16 were evaluable for this analysis. Primary tumors were in extremity (n=5) or central axis (n=11). Eight patients had MET disease (pulmonary only, n=4). Median (range) decrease in tumor size by WHO after C4 was 61% (40–92%) for LOC and 83% (47–94%) for MET. Decrease by treatment is presented in the table . Overall responses after 4 cycles for LOC patients were 5 PR, 3 SD using RECIST, and 6 PR, 2 SD using WHO. For MET patients, overall responses were the same using RECIST and WHO, 7 PR, and 1SD. Conclusion: Patients with MET EWS responded as well as those with LOC EWS after 4 cycles of neoadjuvant chemotherapy. Similar overall response was demonstrated using RECIST or WHO. Tumor response after VDC was greater than after IE, possibly due to sequence of administration, but patients had continued tumor response with IE.

[Table: see text]

No significant financial relationships to disclose.

NF1 plexiform neurofibroma growth rate by volumetric MRI: Relationship to age and body weight

OBJECTIVE

To longitudinally analyze changes in plexiform neurofibroma (PN) volume in relation to age and body growth in children and young adults with neurofibromatosis type 1 and inoperable, symptomatic, or progressive PNs, using a sensitive, automated method of volumetric MRI analysis.

METHODS

We included patients 25 years of age and younger with PNs entered in a natural history study or in treatment trials who had volumetric MRI over > or =16 months.

RESULTS

We studied 49 patients (median age 8.3 years) with 61 PNs and a median evaluation period of 34 months (range 18 to 70). The PN growth rates varied among patients, but were constant within patients. Thirty-four patients (69%) experienced > or =20% increase in PN volume during the observation period. PN volume increased more rapidly than body weight over time (p = 0.026). Younger patients had the most rapid PN growth rate.

CONCLUSIONS

Volume increase of plexiform neurofibromas is a realistic and meaningful trial endpoint. In most patients plexiform neurofibroma growth rate exceeded body growth rate. The youngest patients had the fastest plexiform neurofibroma growth rate, and clinical drug development should be directed toward this population. Age stratification for clinical trials for plexiform neurofibromas should be considered.

Randomized trial and pharmacokinetic study of pegfilgrastim vs. filgrastim in children and young adults with newly diagnosed sarcoma treated with dose intensive chemotherapy

9020

Background: Daily subcutaneous (SC) filgrastim reduces the duration of severe neutropenia in children receiving dose intensive chemotherapy. A single SC dose of pegfilgrastim may be as efficacious. Methods: We conducted a randomized, non-inferiority trial comparing neutrophil recovery, tolerability, and pharmacokinetics of pegfilgrastim (100 mcg/kg SC once/cycle) to filgrastim (5 mcg/kg SC daily until post nadir ANC >10,000) in children and young adults with newly diagnosed sarcoma treated with vincristine, doxorubicin, and cyclophosphamide (VDC) for cycles 1, 2, 5, 9, 11, 13 alternating with etoposide and ifosfamide (IE) for cycles 3, 4, 6–8, 10, 12, 14. Local control with radiation or surgery was initiated after cycle 5. Serum GCSF concentrations were monitored during cycle 1 and measured by ELISA. Complete blood counts were monitored thrice weekly during cycles 1–4. Cycle duration was collected for all cycles. Results: Accrual has been completed. 34 patients (median age 19 y, range 3–25 y) were enrolled, 28 have completed 4 cycles, and 26 have completed therapy. Growth factor associated toxicity included reversible transaminase elevation and arthralgias and was similar on the 2 treatment arms. For filgrastim (n=13) the median (range) GCSF Cmax was 12 ng/mL (4–16 ng/mL), Css was 7 ng/mL (2–9 ng/mL) and Tmax was 6 h (4–8 h). For pegfilgrastim (n=13), the median (range) GCSF Cmax was 69 ng/mL (11–235 ng/mL), Css was 43 ng/mL (7–151 ng/mL) and Tmax was 28 h (4–168 h). Median (range) neutrophil recovery and cycle duration are presented in the table. Conclusion: Pegfilgrastim was well tolerated. Peak and steady state serum GCSF concentrations were higher in patients receiving pegfilgrastim but more variable. The number of days of severe neutropenia and the cycle duration with single dose pegfilgrastim appear to be at least equivalent to daily filgrastim.

[Table: see text]

No significant financial relationships to disclose.

Topoisomerase II-alpha expression increases with increasing Gleason score and with hormone insensitivity in prostate carcinoma

AIM

To investigate and compare topoisomerase II-alpha expression in benign prostatic hyperplasia (BPH), prostate cancer of varying Gleason scores and hormone-insensitive prostate cancer.

METHODS

The immunohistochemical expression of topoisomerase II-alpha antibody in the above-mentioned diagnostic categories was investigated and compared.

RESULTS

Increased expression of topoisomerase II-alpha was seen in the prostate cancers of Gleason scores 7 and 8-10 (p = 0.000) compared with prostate cancers of Gleason score 6 and BPH (p = 0.245). Statistically significant differences were found in the topoisomerase II-alpha gene expression between prostate cancers categorised by Gleason Score. Also, increased expression of topoisomerase II-alpha was seen in the known hormone-resistant prostate carcinomas compared with prostate cancers with no hormone treatment in the subgroup with Gleason scores 8-10, which approached statistical significance (p = 0.081). No statistically significant difference was observed in topoisomerase II-alpha expression between the groups with BPH and prostate carcinoma of Gleason score 6 (p = 0.245).

CONCLUSION

Topoisomerase II-alpha expression was found to increase with the known prognostic marker Gleason score and with hormone insensitivity. Objective evidence is provided for clinical trials with drugs targeting topoisomerase II-alpha to be targeted to patients with prostate cancers of Gleason Score >6 and, in particular, prostate cancers of Gleason Scores 8-10.

Could nursery rhymes cause violent behaviour? A comparison with television viewing

AIMS

To assess the rates of violence in nursery rhymes compared to pre-watershed television viewing.

METHODS

Data regarding television viewing habits, and the amount of violence on British television, were obtained from Ofcom. A compilation of nursery rhymes was examined for episodes of violence by three of the researchers. Each nursery rhyme was analysed by number and type of episode. They were then recited to the fourth researcher whose reactions were scrutinised.

RESULTS

There were 1045 violent scenes on pre-watershed television over two weeks, of which 61% showed the act and the result; 51% of programmes contained violence. The 25 nursery rhymes had 20 episodes of violence, with 41% of rhymes being violent in some way; 30% mentioned the act and the result, with 50% only the act. Episodes of law breaking and animal abuse were also identified. Television has 4.8 violent scenes per hour and nursery rhymes have 52.2 violent scenes per hour. Analysis of the reactions of the fourth researcher were inconclusive.

CONCLUSIONS

Although we do not advocate exposure for anyone to violent scenes or stimuli, childhood violence is not a new phenomenon. Whether visual violence and imagined violence have the same effect is likely to depend on the age of the child and the effectiveness of the storyteller. Re-interpretation of the ancient problem of childhood and youth violence through modern eyes is difficult, and laying the blame solely on television viewing is simplistic and may divert attention from vastly more complex societal problems.

The right-to-die movement: extrapolating from the National Hemlock Society U.S.A. membership survey

A national membership survey of Hemlock Society USA was conducted by Fox and Kamakahi (1995). Respondents (N=6398) were asked a variety of questions, but in this paper we perform a longitudinal analysis of the characteristics of Hemlock Society USA members. Hemlock Society USA members are divided into three 5-year cohorts: Early Joiners (11 or more years of membership), Middle Joiners (6 to 10 years membership), and Late Joiners (5 or fewer years of membership). Differences between cohorts are examined and extrapolations made regarding Hemlock Society USA and the Right-to-Die Movement. A series of one-way ANOVAs were used with Scheme post-hoc comparisons as heuristic tools for assessing between-cohort differences. Late Joiners are different from earlier members, but are more like other Hemlock Society USA members than the adult U.S. population at large. Hemlock Society USA members are essentially societal "elites" (based on socio-demographic variables) who work in social environments that are decidedly split on the issue of voluntary suicide and euthanasia.

Do threatening stimuli draw or hold visual attention in subclinical anxiety?

Biases in information processing undoubtedly play an important role in the maintenance of emotion and emotional disorders. In an attentional cueing paradigm, threat words and angry faces had no advantage over positive or neutral words (or faces) in attracting attention to their own location, even for people who were highly state-anxious. In contrast, the presence of threatening cues (words and faces) had a strong impact on the disengagement of attention. When a threat cue was presented and a target subsequently presented in another location, high state-anxious individuals took longer to detect the target relative to when either a positive or a neutral cue was presented. It is concluded that threat-related stimuli affect attentional dwell time and the disengage component of attention, leaving the question of whether threat stimuli affect the shift component of attention open to debate.

District nursing associations and doctors: aspects of interprofessional relationships, 1902-1914

District nursing associations' midwifery was the key to their early twentieth-century growth, which would have been impossible without doctors' co-operation. Yet doctors were reportedly hostile to district nurses in this period, and had particular reasons for resisting their midwifery. Here it is argued that the Queen's Institute's co-ordination of the associations' work, and its conduct of negotiations with the British Medical Association, promoted arrangements under which doctors were likely to gain more than they feared losing by accepting district nurses' midwifery.

Midwifery in England and Wales before 1936: handywomen and doctors

The social history of medicine incorporates a respectable body of research on maternity care in Britain, but illegal midwifery in the 1920s and 1930s remains inadequately understood. Midwives' statutory regulation began with the Midwives Act of 1902, which was implemented over the eight years to 1910. The licensing body for England and Wales was the Central Midwives Board, which enrolled midwives with approved qualifications and, initially, others who were untrained but who were accepted as having been in 'bona fide' practice before the legislation. Its effect was to prohibit midwifery by the untrained 'handywomen' on whom many poorer women had formerly relied (1). The 'bona fide' enrolments covered some such practice, but it otherwise became illegal.

Validity of pulp-to-palm distance as a measure of finger flexion

This study investigated the validity of pulp-to-palm distance measures as clinical indicators of finger flexion capacity. Pulp-to-palm distance and goniometry of the metacarpophalangeal, proximal interphalangeal and distal interphalangeal joints were measured by a single tester in 50 patients with abnormal digital flexion using a computerized hand assessment system. The correlation between pulp-to-palm distance measurements and total finger flexion measures obtained by goniometry, was moderate (r=-0.46 and -0.51). This indicates that the measures are not interchangeable. The relationship between an upper extremity disability score (DASH) and restricted motion was stronger for the goniometric measurements (r=0.45, P<0.01) than for the pulp-to-palm distance measurements (r<0.30, P>0.01). Both types of range of motion measurements were able to discriminate between minimal and substantial upper extremity disability. Further methodological evaluation is required to support the use of pulp-to-palm distance measures as an outcome indicator.

Inhibitory effects of repeating color and shape: inhibition of return or repetition blindness?

There is a current debate regarding whether attention is influenced by stimulus attributes other than location. The present article replicates and extends previous findings that repeating the nonspatial attribute of color leads to a delay in target detection (M. B. Law, J. Pratt, & R. A. Abrams, 1995). Repetition disadvantage effects were found for the stimulus attributes of both color and shape, as well as for location. However, the nonspatial repetition disadvantage disappeared if the stimuli were presented in peripheral locations (Experiments 3a, 3b, and 4) or the cue was presented for 50 ms (Experiment 6). Moreover, the magnitude of the repetition disadvantage tended to decline as the cue-target stimulus-onset asynchrony increased (Experiments 5a, 5b, and 6). These results suggest that a repetition blindness mechanism may underlie the repetition disadvantage effects of nonspatial features, rather than an inhibition of return mechanism.

Inhibitory effects of repeating color and shape: inhibition of return or repetition blindness?

There is a current debate regarding whether attention is influenced by stimulus attributes other than location. The present article replicates and extends previous findings that repeating the nonspatial attribute of color leads to a delay in target detection (M. B. Law, J. Pratt, & R. A. Abrams, 1995). Repetition disadvantage effects were found for the stimulus attributes of both color and shape, as well as for location. However, the nonspatial repetition disadvantage disappeared if the stimuli were presented in peripheral locations (Experiments 3a, 3b, and 4) or the cue was presented for 50 ms (Experiment 6). Moreover, the magnitude of the repetition disadvantage tended to decline as the cue-target stimulus-onset asynchrony increased (Experiments 5a, 5b, and 6). These results suggest that a repetition blindness mechanism may underlie the repetition disadvantage effects of nonspatial features, rather than an inhibition of return mechanism.

Functional analysis of patient-derived mutations in the Fanconi anemia gene, FANCG/XRCC9

OBJECTIVE

Fanconi anemia (FA) is an autosomal-recessive cancer susceptibility syndrome with seven complementation groups. Six of the FA genes have been cloned (corresponding to subtypes A, C, D2, E, F, and G) and the encoded proteins interact in a common pathway. Patient-derived mutations in FA genes have been helpful in delineating functional domains of FA proteins. The purpose of this work was to subtype FA patient-derived cell lines in our repository and to identify FA gene mutations.

METHODS

We subtyped 62 FA patients as type A, G, C, or non-ACG by using a combination of retroviral gene transfer and immunoblot analysis. Among these FA patients, we identified six FA-G patients for further analysis. We used a strategy involving amplification of FANCG/XRCC9 exons and direct sequencing to identify novel FANCG mutations in cell lines derived from these FA-G patients. We functionally analyzed FANCG mutant alleles by transducing the corresponding cDNAs into a known FA-G indicator cell line and scoring correction of MMC sensitivity.

RESULTS

Our results demonstrate a wide range of mutations in the FANCG gene (splice, nonsense, and missense mutations). Based on this mutational screen, a carboxy terminal functional domain of the FANCG protein appears to be required for complementation of FA-G cells and for normal assembly of the FANCA/FANCG/FANCC protein complex.

CONCLUSION

The identification of patient-derived mutant alleles of FA genes can provide important insights to the function of FA proteins. FA subtyping is also a necessary precondition for gene therapy.

Plasma pharmacokinetics and cerebrospinal fluid penetration of hypericin in nonhuman primates

Hypericin, a polycyclic aromatic dianthroquinone, is a natural pigment derived from the plant Hypericum perforatum (St John's Wort). The compound has been synthesized and shown to inhibit the growth of malignant glioma cell lines in vitro via inhibition of protein kinase C. Oral hypericin has entered clinical trials in adults with recurrent malignant glioma.

PURPOSE

The present study was performed to characterize the plasma pharmacokinetics (PK) and cerebrospinal fluid (CSF) penetration of hypericin in nonhuman primates.

METHODS

Hypericin was administered as an intravenous bolus dose of 2 mg/kg (n = 3) or 5 mg/kg (n = 1). Plasma and CSF (ventricular or lumbar) were sampled prior to administration and at frequent intervals for up to 50 h after administration of the drug. Hypericin concentrations in plasma and CSF were determined using a specific reverse-phase HPLC assay.

RESULTS

Mean peak plasma concentration of hypericin following the 2 mg/kg dose was 142 +/- 45 microM. Elimination of hypericin from plasma was biexponential, with an average alpha half-life of 2.8 +/- 0.3 h and average terminal half-life of 26 +/- 14 h.

CONCLUSIONS

The 2 mg/kg dose in the nonhuman primate was sufficient to maintain plasma concentrations above 10 microM (the in vitro concentration required for growth inhibition of human glioma cell lines) for up to 12 h. No hypericin was detected in the CSF of any animal (lower limit of detection 0.1 microM); the CSF penetration is therefore less than 1%. A severe dose-limiting photosensitivity skin rash was seen at the 5 mg/kg dose level.

Probe calibration in transient microdialysis in vivo

PURPOSE

We examine the theoretical basis for calibrating microdialysis probes in vivo for pharmacokinetic experiments in which the extracellular analyte concentrations vary in time.

METHODS

A software package, MICRODIAL. was used to simulate microdialysis for illustrative transient situations with linear concentration dependence.

RESULTS

For a constant distant extracellular analyte concentration. the calibration factor (extraction fraction, Ed) exhibits a mass transfer transient associated with the development of spatial concentration profiles within the tissue and the probe. Processes clearing the analyte from the extracellular fluid (ECF) strongly influence the rapidity of approach to steady-state and affect the magnitude of the steady-state calibration factor, Ess(d). For situations in which the distant ECF concentration varies in time as a result of exchange with the plasma compartment, different time profiles of the distant ECF and plasma concentrations yield different transient E(d). For the linear, transient cases examined, the area-under-the-curve (AUC 0-infinity) time integral of the distant ECF concentration was found to be proportional to the outflow dialysate concentration-time integral with Ess(d) being the proportionality constant.

CONCLUSIONS

The options for calibrating microdialysis probes in solid tissues appear limited under non-steady state conditions; however, AUC integrals for linear systems may be determined by continuous microdialysis sampling and steady-state probe calibration approaches.

Target selection difficulty, negative priming, and aging

It has been recently suggested that the presence of identity negative priming effects in old adults could occur when there is substantial processing of the distracting information in a selective attention task (J. M. Kieley & A. A. Hartley, 1997). In three experiments, using a letter identification task, it was found that making target selection more difficult increased the magnitude of the negative priming effect to a similar extent in both young and old adults. Moreover, the size of the negative priming effect did not differ between young and elderly participants. These results are discussed with respect to the issue of age-related deficits in the mechanisms underlying negative priming.

The role of perceptual load in negative priming

Negative priming (NP) effects from irrelevant distractors were assessed as a function of perceptual load in the processing of prime targets. Participants searched for a target letter among a varying number of nontarget letters in the center of the display and ignored an irrelevant peripheral distractor. NP from this distractor was found to depend on the relevant search set size, decreasing as this set size was increased. The authors conclude that exhausting attention in relevant processing reduces irrelevant processing (e.g., N. Lavie, 1995), leaving less distractor processing to produce NP. This conclusion is consistent with recent reactive inhibition views for NP (e.g., G. Houghton, S. P. Tipper, B. Weaver, & D. I. Shore, 1996).

Transmitral Doppler: a new transthoracic contrast method for patent foramen ovale detection and quantification

OBJECTIVES

This study compared a new transthoracic echocardiographic (TTE) method for detection of right to left bubble passage, transmitral Doppler (TMD), against two-dimensional (2D) TTE contrast study and the gold standard, of transesophageal echocardiography (TEE), and assessed its utility in quantitative assessment of patent foramen ovales (PFO).

BACKGROUND

Current TTE methods are relatively insensitive in PFO detection and do not allow quantitative assessment of right to left shunt.

METHODS

In 44 patients (59 years, range 34 to 76 years) saline contrast and color Doppler studies were performed in three conditions--TTE TMD, TTE 2D and TEE. Bubble transit on the TMD was measured semiquantitatively by a visual bubble score and objectively by integrating the acoustic power within the mitral velocity envelope.

RESULTS

By TEE it was determined that 17 patients (39%) had PFOs; 16 had right to left contrast passage, and only 1 had left to right flow by color Doppler. Against TEE contrast study, the sensitivity of TMD and 2D contrast studies were 100% and 75%, respectively, with specificity of 96% and 100%. Greater than 10 bubbles on a single beat of the resting contrast TMD identified patients with a maximum resting TEE PFO opening diameter >2 mm with 78% sensitivity and 100% specificity. There was a strong correlation (r2 = 0.72, p<0.01) between the TMD acoustic power and PFO opening diameter.

CONCLUSIONS

Transmitral Doppler is a sensitive and specific method for TTE PFO detection that allows quantification of right to left bubble passage and may obviate the need for TEE in many patients after stroke.

Target selection difficulty, negative priming, and aging

It has been recently suggested that the presence of identity negative priming effects in old adults could occur when there is substantial processing of the distracting information in a selective attention task (J. M. Kieley & A. A. Hartley, 1997). In three experiments, using a letter identification task, it was found that making target selection more difficult increased the magnitude of the negative priming effect to a similar extent in both young and old adults. Moreover, the size of the negative priming effect did not differ between young and elderly participants. These results are discussed with respect to the issue of age-related deficits in the mechanisms underlying negative priming.

Pretransfusion testing without serologic crossmatch: approaches to ensure patient safety

BACKGROUND AND OBJECTIVES

A crossmatch is usual in pretransfusion testing, but we eliminated it at our tertiary care university hospital. In place of the crossmatch, we have introduced a system where, if an antibody screen is negative, two technologists confirm the ABO of the same patient sample, and we release blood of the patient's type without a serologic or electronic crossmatch.

MATERIALS AND METHODS

In 65,628 samples received for pretransfusion testing, we studied the effect of common errors that occur from the time of receipt of a sample until release of the blood unit, in order to decide if elimination of the serologic crossmatch would affect patient safety. All sample labels were inspected for acceptability.

RESULTS

A total of 1,082 (1.64%) samples were rejected for mislabeling. Discordance in patient ABO typing results between two technologists was 0.43%. Such discrepancies were resolved before the release of blood units. No donor unit mislabeling or unit release errors were detected.

CONCLUSION

Elimination of the crossmatch for red cell antibody-negative patients is safe provided a system of error detection is used. This enhances patient care through the quicker release of blood, increased laboratory efficiency and decreased costs.

The role of perceptual load in negative priming

Negative priming (NP) effects from irrelevant distractors were assessed as a function of perceptual load in the processing of prime targets. Participants searched for a target letter among a varying number of nontarget letters in the center of the display and ignored an irrelevant peripheral distractor. NP from this distractor was found to depend on the relevant search set size, decreasing as this set size was increased. The authors conclude that exhausting attention in relevant processing reduces irrelevant processing (e.g., N. Lavie, 1995), leaving less distractor processing to produce NP. This conclusion is consistent with recent reactive inhibition views for NP (e.g., G. Houghton, S. P. Tipper, B. Weaver, & D. I. Shore, 1996).

Patients who want their family and physician to make resuscitation decisions for them: observations from SUPPORT and HELP. Study to Understand Prognoses and Preferences for Outcomes and Risks of Treatment. Hospitalized Elderly Longitudinal Project

OBJECTIVE

To determine the extent to which older or seriously ill inpatients would prefer to have their family and physician make resuscitation decisions for them rather than having their own stated preferences followed if they were unable to decide themselves.

DESIGN

Analysis of existing data from the Hospitalized Elderly Longitudinal Project (HELP) and the Study to Understand Prognoses and Preferences for Outcomes and Risks of Treatment (SUPPORT).

SETTING

Five teaching hospitals in the United States.

PARTICIPANTS

2203 seriously ill adult inpatients (SUPPORT) and 1226 older inpatients (HELP) who expressed preferences about resuscitation and about advance decision-making.

MEASURES

We used a logistic regression model to determine which factors predicted preferences for family and physician decision-making.

RESULTS

Of the 513 HELP patients in this analysis, 363 (70.8%) would prefer to have their family and physician make resuscitation decisions for them whereas 29.2% would prefer to have their own stated preferences followed if they were to lose decision-making capacity. Of the 646 SUPPORT patients, 504 (78.0%) would prefer to have their family and physician decide and 22.0% would prefer to have their advance preferences followed. Independent predictors of preference for family and physician decision-making included not wanting to be resuscitated and having a surrogate decision-maker.

CONCLUSIONS

Most inpatients who are older or have serious illnesses would not want their stated resuscitation preferences followed if they were to lose decision-making capacity. Most patients in both groups would prefer that their family and physician make resuscitation decisions for them. These results underscore the need to understand resuscitation preferences within a broader context of patient values.

Rethinking fundamental assumptions: SUPPORT's implications for future reform. Study to Understand Prognoses and Preferences and Risks of Treatment

BACKGROUND

The intervention in SUPPORT, the Study to Understand Prognoses and Preferences for Outcomes and Risks of Treatments, was ineffective in changing communication, decision-making, and treatment patterns despite evidence that counseling and information were delivered as planned. The previous paper in this volume shows that modest alterations in the intervention design probably did not explain the lack of substantial effects.

OBJECTIVE

To explore the possibility that improved individual, patient-level decision-making is not the most effective strategy for improving end-of-life care and that improving routine practices may be more effective.

DESIGN

This paper reflects our efforts to synthesize findings from SUPPORT and other sources in order to explore our conceptual models, their consistency with the data, and their leverage for change.

RESULTS

Many of the assumptions underlying the model of improved decision-making are problematic. Furthermore, the results of SUPPORT suggest that implementing an effective intervention based on a normative model of shared decision-making can be quite difficult. Practice patterns and social expectations may be strong influences in shaping patients' courses of care. Innovations in system function, such as quality improvement or changing the financing incentives, may offer more powerful avenues for reform.

CONCLUSIONS

SUPPORT's intervention may have failed to have an impact because strong psychological and social forces underlie present practices. System-level innovation and quality improvement in routine care may offer more powerful opportunities for improvement.

Evaluation of prognostic criteria for determining hospice eligibility in patients with advanced lung, heart, or liver disease. SUPPORT Investigators. Study to Understand Prognoses and Preferences for Outcomes and Risks of Treatments

CONTEXT

Many individuals involved with care of the dying advocate expanding access to hospice care for persons with advanced lung, heart, or liver disease. However, to be eligible, these patients generally must have a prognosis for survival of less than 6 months.

OBJECTIVE

To test the ability of currently available criteria to identify a population with a survival prognosis of 6 months or less among seriously ill hospitalized patients with 1 of 3 commonly fatal chronic diseases.

DESIGN

Validation study using data from the Study to Understand Prognoses and Preferences for Outcomes and Risks of Treatments (SUPPORT) phase 1 (June 1989-June 1991) and phase 2 (January 1992-January 1994), with a 6-month follow-up.

SETTING AND PATIENTS

Consecutive sample of 2607 seriously ill patients from 5 US medical centers who were hospitalized with chronic obstructive pulmonary disease, congestive heart failure, or end-stage liver disease, and who survived to hospital discharge.

MAIN OUTCOME MEASURES

Descriptive and operating characteristics of 5 general and 2 disease-specific clinical criteria for identifying patients with a survival prognosis of 6 months or less, and 3 sets of combination criteria (broad, intermediate, and narrow inclusion) aimed at providing low, medium, and high thresholds for hospice eligibility based on National Hospice Organization guidelines.

RESULTS

Seventy-five percent of the sample survived more than 6 months after hospital discharge; 44% expressed a preference for palliative care. Broad inclusion criteria identified 923 patients eligible for hospice care, of whom 70% survived longer than 6 months. Intermediate inclusion criteria identified 300 patients, of whom 65% survived longer than 6 months. Narrow inclusion criteria identified 19 patients, of whom 53% survived longer than 6 months. Sensitivities and specificities of the combination criteria were 41.7% and 66.7% (broad inclusion), 16.2% and 90.1 % (intermediate inclusion), and 1.4% and 99.5% (narrow inclusion), respectively.

CONCLUSIONS

These data indicate that for seriously ill hospitalized patients with advanced chronic obstructive pulmonary disease, congestive heart failure, or end-stage liver disease, recommended clinical prediction criteria are not effective in identifying a population with a survival prognosis of 6 months or less.

Parasite density and malaria morbidity in the Pakistani Punjab

The relationship between quantitative Plasmodiumfalciparum or P. vivax parasitemia and clinical illness has not been defined in Pakistan or in other areas where malaria transmission is not highly endemic. Standardized questionnaires were given to and physical examinations and parasitologic tests were performed in 8,941 subjects seen in outpatient clinics in 4 villages for 13 consecutive months in the Punjab region of Pakistan. The results, based on multivariable analysis, showed that a clinical diagnosis of malaria, a history of fever, rigors, headache, myalgia, elevated temperature, and a palpable spleen among children were all strongly associated with the presence and density of P. falciparum or P. vivax malaria in a monotonic dose-response fashion. The malaria attributable fraction of a clinical diagnosis of malaria, and the same symptoms and signs also increased with increasing P. falciparum and, to a lesser extent, P. vivax, parasitemia. Unlike in sub-Saharan Africa, clinical illness due to malaria often occurs in the Punjab among adolescents and adults and in patients with parasite densities less than 1,000/microl. Clinical guidelines based upon parasitemia and symptomatology must be adjusted according to the intensity of transmission and be specific for each geographic area.

Incorporating palliative care into critical care education: principles, challenges, and opportunities

OBJECTIVE

To identify the goals and methods for medical education about end-of-life care in the intensive care unit (ICU).

DATA SOURCES AND STUDY SELECTION

A status report on palliative care, a summary report of recent research on palliative care education, articles in the medical literature on end-of-life care and critical care, and expert opinion were considered.

DATA EXTRACTION

A working group, including specialists in critical care, palliative care, medical ethics, consumer advocacy, and communications, was convened at the "Medical Education for Care Near the End of Life National Consensus Conference." A modified nominal group process was used to develop a consensus.

DATA SYNTHESIS

In the ICU, life and death decisions are often made in a crisis mode or in the face of uncertainty, and may necessitate the withholding and withdrawal of life-supporting technologies. Because critical illness often diminishes the capacity of patients to make decisions, clinicians must often make decisions in conjunction with surrogates, rather than with patients. Discontinuity of care can threaten trusting relationships, and cultural diversity can have a particularly powerful impact on choices for care. In the face of these realities, it is possible and appropriate to give compassionate palliative care to dying patients and their families in the ICU.

CONCLUSIONS

Teaching care of the dying in the ICU should emphasize the following: a) the goals of care should guide the use of technology; b) understanding of prognostication and treatment withholding and withdrawal is essential; c) effective communication and trusting relationships are crucial to good care; d) cultural differences should be acknowledged and respected; and e) the delivery of excellent palliative care is appropriate and necessary when patients die in the ICU.

Quantitative RT-PCR to evaluate in vivo expression of multiple transgenes using a common intron

An assay measuring RNA expression levels of a gene-encoded therapeutic must distinguish between endogenous mRNA and mRNA transcribed from the transgene. Specificity for the delivered transgene is especially critical when the treatment involves genes that are expressed in the target tissue. To facilitate uniform detection of transgene RNA without interference from endogenous mRNA, we have engineered expression vectors that include a 5' untranslated region (5' UTR) containing a synthetic intron (PGL3). The synthetic intron splice junction was the target sequence for a quantitative reverse transcription (RT)-PCR assay utilizing Taq-Man technology. In this study, we demonstrate that a quantitative RT-PCR assay designed to recognize an engineered intron splice site in the 5'UTR of expression constructs effectively measures the expression level of in vivo-delivered gene therapeutics.

SDQR migrations in Caenorhabditis elegans are controlled by multiple guidance cues and changing responses to netrin UNC-6

The netrin guidance cue, UNC-6, and the netrin receptors, UNC-5 and UNC-40, guide SDQR cell and axon migrations in C. elegans. In wild-type larvae, SDQR migrations are away from ventral UNC-6-expressing cells, suggesting that UNC-6 repels SDQR. In unc-6 null larvae, SDQR migrations are towards the ventral midline, indicating a response to other guidance cues that directs the migrations ventrally. Although ectopic UNC-6 expression dorsal to the SDQR cell body would be predicted to cause ventral SDQR migrations in unc-6 null larvae, in fact, more migrations are directed dorsally, suggesting that SDQR is not always repelled from the dorsal source of UNC-6. UNC-5 is required for dorsal SDQR migrations, but not for the ventral migrations in unc-6 null larvae. UNC-40 appears to moderate both the response to UNC-6 and to the other cues. Our results show that SDQR responds to multiple guidance cues and they suggest that, besides UNC-6, other factors influence whether an UNC-6 responsive cell migrates toward or away from an UNC-6 source in vivo. We propose that multiple signals elicited by the guidance cues are integrated and interpreted by SDQR and that the response to UNC-6 can change depending on the combination of cues encountered during migration. These responses determine the final dorsoventral position of the SDQR cell and axon.