Comparative genomic and protein signatures and intratumoral treatment responses in patients with metastatic breast cancer (MBC) treated with paclitaxel (PTX) and 2-methoxyestradiol (2ME2)

e22049

Background: Tumors respond to both chemotherapy and radiation through a number of poorly understood survival mechanisms. These potential mechanisms include upregulation of anti-apoptotic and pro-angiogenic pathways, including those regulated by HIF-1α. Sequential MBC biopsies were used to examine 1) the effects of PTX on intratumoral HIF-1α mediated pathways; and 2) the ability of a HIF-1α inhibitor (2ME2) to modulate the tumor's HIF- 1α response to PTX. Methods: Key eligibility included pts with MBC, ECOG 0–2, unlimited prior therapies, and biopsiable tumors. Pts were treated on a 28-day schedule with weekly PTX (90 mg/m2 D1, D8, D15) and daily oral 2ME2 (1000, 1250,1500 or 2000 mg qid starting D8) and had 3 tumor biopsies: baseline (A); D8 post-PTX/pre-2ME2 (B); D22 post-PTX/post- 2ME2 (C). Serial biopsies were compared for genomic and single protein changes. Results: 20 pts (median age 52 yrs [31- 75]) were treated. 60% had ≥2 prior regimens for MBC, 35% had ≥3. No unexpected grade 3/4 toxicities were seen: neutropenia (n=6), anemia (2), hypophosphatemia (2), PE (1). The clinical benefit rate was 25% (4 PR, 1 SD). There were 13 pairs of tumor biopsies to compare points A/B and 10 to compare B/C. There were no consistent gene expression changes between A and B. Significant differences at C vs. B included changes in hypoxia-responsive genes (including CA9, HIF-2α) and upregulation of pro- angiogenic factors and hemoglobin transcripts. For the B/C comparison, 2 distinct groups emerged: the first (biopsy site liver) showed downregulation of gene expression programs driven by ER and the second (lymph node, breast) showed upregulation of endothelial cell- related genes. Conclusions: Combination therapy with PTX and 2ME2 is a well-tolerated and viable option for delaying disease progression for patients with heavily pretreated MBC. Significant gene expression changes before and after exposure to 2ME2 may reflect changes in tumor microcirculation consistent with the idea of vascular normalization. The potential significance of the differences in gene expression observed in the 2 distinct groups remains to be investigated. Supported by Komen Grant BCTR0504044 (MWD).

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An open-label, dose escalation, safety, and pharmacokinetic study of ENMD-2076 administered orally to patients with advanced cancer

3520

Background: ENMD-2076, a novel, orally-active antimitotic and antiangiogenic molecule inhibits Aurora A as well as tyrosine kinases that drive tumor vascularization, including VEGFR2 (KDR), PDGFR and the FGF receptors. This Phase 1 study was designed to evaluate the safety, pharmacokinetics (PK) and preliminary efficacy of ENMD-2076 administered once daily to patients (pts) with advanced cancer. Methods: The dose escalation scheme utilizes 3 (or 4) + 3 (or 2) design. Pts receive ENMD-2076 once daily in 28-day cycles (followed by 7–14 days of rest between cycles 1 and cycle 2 only). Results: 14 pts have been enrolled in 3 dose cohorts (range 60 to 120 mg/m2/d). Median age/performance status is 62/1. The total number of treatment cycles to date is 45, with a median of 3 cycles (range <1 to 9 cycles). Most frequent, related toxicities (all grades, n=14) were hypertension (29%), fatigue (21%), proteinuria and diarrhea (both 14%). One pt experienced dose limiting toxicity of Grade 4 hypertension and Grade 3 cholecystitis in the first dose cohort of 60 mg/m2/d. Following drug interruption, the pt restarted at 30 mg/m2/d and continued for 4 additional cycles before being removed for progressive disease. Noncompartmental PK analysis of the first two dose levels shows that the plasma concentration of ENMD-981693 (the active free base of ENMD-2076) is dose- linear, as reflected in AUC and Cmax. The estimated terminal half-life (t1/2) is unaltered regardless of dose; however, t1/2 is approximately 50% greater at steady state than following single dose administration. Four ovarian cancer and 2 colon cancer pts have achieved decreases ranging from 11–61% in either CA125 or CEA, respectively (4 are associated with stable disease at Cycle 2 by modified RECIST criteria). Serum KDR concentrations assayed by ELISA decreased from baseline in all patients on treatment from a mean of 9153 pg/mL (SEM 464.2) at D1 to 6987 pg/mL (SEM 460.0) at D28 (p <0.05). Conclusions: ENMD-2076 is a small molecule kinase inhibitor with acceptable toxicity and preliminary evidence of antitumor activity in pts with ovarian and colorectal cancers.

[Table: see text]

Phase I/II study of MKC-1 and pemetrexed (PEM) as second-line therapy in patients (pts) with advanced non-small cell lung cancer (NSCLC)

e19005

Background: MKC-1 is a novel oral cell cycle inhibitor with preclinical activity against NSCLC cell lines including multi-drug resistant lines, and single agent activity in NSCLC pts. Binding targets of MKC-1 include microtubules, members of the importin-β family and AKT-mTOR. This phase 1/2 study evaluated MKC-1 in combination with PEM as second-line therapy in pts with advanced NSCLC. Methods: Eligible pts had NSCLC previously treated with one regimen for metastatic disease or disease progression within one year following adjuvant and neoadjuvant therapy. Phase 1 dose escalation used 3+3 design. Phase 2 pts were treated with MKC-1 at 75 mg/m2 given p.o. BID for 14 days along with PEM at 500 mg/m2 given i.v. on day 1 of each 21 day cycle. Following 4 cycles of combined treatment, single agent MKC-1 was continued as maintenance therapy. An interim analysis after 17 pts in phase 2 would allow accrual to continue provided one response was confirmed. Results: 27 pts were enrolled (8 in phase 1 and 19 in phase 2). Median age/PS for phase 2 is 64/1 and 89% had adenocarcinoma. Total # of treatment cycles to date for phase 2 pts is 95, with a median of 4 cycles. Of the 19 phase 2 pts, 18 were evaluable for tumor response. The best response was confirmed PR, noted in 3 pts. 5 additional pts (4 confirmed) had minor responses (>10% but <30% shrinkage). One additional pt continues on study with stable disease for >18 months. In phase 2 (n=19), all grade toxicities were anorexia (59%), fatigue (63%), nausea (58%), and dyspnea (48%). Grade 3/4 toxicities included fatigue (26%); neutropenia (22%); dyspnea, anorexia, AST and ALT elevation (11% each); nausea and constipation (5% each). 7 pts had at least one dose reduction of both PEM and MKC-1 and 3 additional pts had only MKC-1 reduced. Median PFS was 86 days with two pts continuing on study (treated for 530+ days and 140+ days, respectively). Conclusions: The phase 2 dose of MKC-1 (75 mg/m2 BID) and PEM (500 mg/m2) has been defined. The combination is well tolerated with 17% of patients achieving a confirmed PR thus far. A decision to proceed with additional accrual in this single arm study versus initiating a randomized phase 2 study of this combination is pending.

[Table: see text]

A single-center, open-label, dose escalation, safety, and pharmacokinetic study of ENMD-1198 administered orally to patients (pts) with advanced cancer

3562

Background: ENMD-1198 (2-methoxyestra-1, 3, 5, (10) 16-tetraene-3-carboxamide), an analog of 2-methoxyestradiol (2ME2), has both antiangiogenic and antiproliferative effects in various tumor types. ENMD-1198 inhibits MT polymerization by binding to β-tubulin at the colchicine-binding site and inhibits HIF-1alpha. This Phase 1 study is evaluating the safety of ENMD-1198 to determine the maximum tolerated dose. Methods: Eligible pts had advanced cancer for which no effective therapy exists that is either evaluable by RECIST criteria or tumor markers that could be monitored for clinical benefit. Phase 1 dose escalation in 3+3 design for first 5 cohorts; modified to 1 pt cohorts for subsequent cohorts until Grade 2 treatment related toxicity, and then standard 3+3 design. All pts treated with once daily oral ENMD-1198 in 28-day cycles (with post-treatment drug-free observation period of 7–14 days in Cycle 1 only). Pts are treated until the appearance of significant treatment-emergent toxicities or disease progression (PD) occurs. Results: To date, 27 pts have been enrolled in 12 dose cohorts (range 5 to 550 mg/m2/d). Median age/performance status is 61/1. Total # of treatment cycles to date is 68, with a median of 2 cycles (range <1 to 15 cycles). Most frequent toxicities (all grades, n=22) were pain (77%), fatigue (55%), constipation (36%), neuropathy and nausea (both 32%), and anemia (27%). 4 pts have experienced stable disease (SD) for more than 2 cycles. There have been no objective responses to date. 2 pts experienced dose limiting toxicity with Grade 4 neutropenia in the 550 mg/m2/d cohort. Following drug holiday, pts restarted at 425 mg/m2/d and continued for at least 1–2 more cycles before being removed from study for PD. One pt (neuroendocrine ca pancreas) is experiencing prolonged SD at 60 mg/m2/d >14 cycles and a 2nd pt (prostate ca) experienced SD at 30mg/m2/d for 10 cycles. ENMD-1198 was absorbed rapidly after oral administration. There was a linear relationship between dose and drug exposure as measured by AUC across all doses (5 - 550 mg/m2). The elimination half-life of ENMD- 1198 averaged more than 12 hours after a single dose. Conclusions: DLT was identified at 550 mg/m2/d. Cohort expansion at 425mg/m2/d is ongoing.

[Table: see text]

Phase II study of 2-methoxyestradiol NanoCrystal dispersion (2ME2) alone and in combination with sunitinib (SU) in patients with metastatic renal cell carcinoma (mRCC) progressing on SU

e16116

Background: Panzem NCD (2ME2) is a non-estrogenic derivative of estradiol with antiproliferative and antiangiogenic activity that downregulates HIF-1α. One mechanism of VEGFR TKI failure may be upregulation of HIF-1α. We hypothesized that 2ME2 may have single-agent activity in pts who previously progressed on SU and that addition of 2ME2 may restore response in pts progressing on SU. Methods: Pts with clear cell mRCC who had previously received or were currently receiving SU with disease progression were eligible. Pts who had previously received SU were treated with 2ME2 alone (arm A). Pts currently on SU continued on the 4:2 schedule, with the addition of 2ME2 (arm B). All pts received 2ME2 at 1,500 mg PO TID, repeated in 6 wk cycles. The primary endpoint was objective response (OR) rate by RECIST. An exploratory endpoint was metabolic response on FDG-PET. Simon optimal 2-stage design was used with plans to enroll 21 pts/arm, and if activity was seen to continue enrollment for a total of 41 pts/arm. Results: 17 pts were enrolled (A: 10; B: 7). Median number of cycles on study was 1 (range <1 to 5). A pt remains on study in cycle 8. Adverse events (AE) of grade 3 or greater occurred in 4 pts (29%). Most frequent AE were: fatigue (71%), diarrhea (50%), dysgeusia (29%), anemia or decreased hemoglobin (29%), and anorexia (21%). Reasons for treatment discontinuation include: disease progression (7), pt/doctor discretion (3), AE (3), and noncompliance (1). No ORs by RECIST were seen. Conclusions: 2ME2 appears to have some single-agent activity, with an MR in a pt removed from study due to AE and a metabolic PR (ΔSUVmax -84%) in a pt with SD by RECIST. With 6/17 pts discontinuing therapy before meeting any OR endpoint, 2ME2 was not tolerable in this population. The study was closed to accrual knowing that a more promising 2ME2 analog is currently under development for oncologic use. The rationale to target HIF-1α after (and during) SU therapy remains of interest. This study design provides a unique way to assess both single-agent and rational combination strategies in pts with mRCC and should be utilized with other agents to seek evidence for clinical activity.

[Table: see text]

The effects of paclitaxel (PTX) and 2-methoxyestradiol (2-ME2) on tumor oxygenation and HIF-1α in breast cancer

3517

Background: Radiation activates HIF-1a via a free radical mediated mechanism associated with reoxygenation. This response could be inhibited, resulting in reduced tumor vascularity and proliferation. Preclinical breast cancer models and a Phase Ib clinical trial (CT) were employed to look at the effects of chemo with or without an oral HIF-1a inhibitor, 2-ME2 (EntreMed) on tumor oxygenation and HIF-1a. Methods: Preclinical models of chemo effects on HIF-1a/oxygenation used 4T1 tumors and either doxorubicin (DOX) or cyclophosphamide (CTX). In addition, MDA-MB-231 tumors were treated with 2-ME2 (5days), and HIF-1a/MVD was assessed. In the CT, up to 15 pts with metastatic breast cancer, and biopsiable (>2 cm) non-bone sites were eligible. Tx was: D 1: PTX, 90 mg/m2; D 8: PTX, 90 mg/m2 with 2-ME2 (cohorts of 1,000/1,250/1,500 mg, qid). PTX was given 3 out of 4 wks. Bxs were done at enrollment, D8 (post-PTX), and D22 (post-PTX/2-ME2). Tumors were examined for changes in HIF-1a and CA9 levels, MVD, and genomic signatures of hypoxia. Plasma was obtained for osteoponin, PAI-1, and VEGF. Results: DOX and CTX both led to increases in HIF-1a, oxygenation, vascularity, and proliferation 4–10 days post treatment in the 4T1 model, while 2-ME2 reduced HIF-1a and MVD post treatment (5 d) in the MDA-MB-231 model. The CT opened in 6–2006, 9 pts have consented and 8 pts have undergone sequential biopsies and accrual continues. No DLT have been seen. Biopsy sites include chest wall, liver, and LN. Sufficient tissue/RNA/plasma has been obtained and the planned analyses will be presented. Conclusions: HIF-1a and tumor oxygenation appear to be modulated as a response to chemotherapy. The combination of PTX and 2-ME2 is clinically active, well-tolerated, and could serve as one of the first approaches to target HIF-1a in order to optimize therapy. Supported by Komen Grant BCTR0504044.

[Table: see text]

Phase 2 study of MKC-1 in patients (pts) with metastatic breast cancer (MBC) who have failed prior therapy with an anthracycline (A) and taxane (T)

11508

Background: MKC-1 (previously Ro 31–7453) is a novel cell cycle inhibitor with significant in vitro and in vivo activity against a wide range of tumor cell lines, including multi-drug resistant cell lines. Proteins identified as binding targets of MKC-1 include microtubules (colchicine binding site) and members of the importin-β family (proteins that play a critical role in nuclear transport and spindle formation). Objective responses (ORs) were observed in heavily pre-treated breast and NSCLC pts (Trigo Perez ASCO’03 A62; Kurup ASCO’03 A2725) treated at a dose of 95 mg/m2 BID given 14 days every 4 weeks with little toxicity. Salazar et al (2004 CCR 10:4374) recommended a higher oral dose (125 mg/m2 BID) on this schedule for further studies. This phase 2 trial is exploring the higher dose to maximize potential anticancer activity. Methods: Pts with MBC who had failed prior A and T and met eligibility criteria received MKC-1 at 125mg/m2 BID x 14d every 4 weeks. Pts with known treated and stable CNS metastases could enroll. Primary objective: OR by RECIST. Should 2 or more of the first 23 evaluable pts have an OR, enrollment will continue to 53 pts. Dose escalation/reductions are required based on toxicity (primarily neutropenia). Results: To date, a total of 20 pts have been enrolled (4 active in Cycles 1–5+). All female; median age/KPS of 60/90. 19% / 13% had received A / T in the neo/adjuvant setting; others had received A / T for metastatic disease. To date, a total of 48 cycles (median 2, range 1–8) were administered; of pts proceeding into Cycle 2, 40% and 20% had the dose increased or reduced, respectively. Severe drug-related toxicity (n=17) was observed in 3 pts (18%): ↑AST/ALT in 2 pts and parathesias in 1 pt. Drug related toxicity: nausea (47%), ↑ALT, diarrhea (both 24%), anemia, ↑AST, cough, fatigue, neutropenia and vomiting (all 18%). Two pts discontinued due to toxicity. One pt had complete resolution of measurable disease (1st observed after Cycle 4, confirmed after Cycle 6 with withdrawal for a new lesion at Cycle 8). An additional 2 pts had stable disease for 5 cycles (1 pt remains active). Conclusions: MKC-1 is well tolerated at the initial recommended dose for this schedule. Activity is observed in pts previously treated with A/T for MBC.

No significant financial relationships to disclose.

Supporting practice teachers to identify failing students

The subject of identifying and supporting failing students in community nursing education programmes has been largely overlooked in the literature, yet is of great concern to practice teachers. This article discusses the views on the topic of a group of practice teachers in the light of existing, related research and proposes a number of indicators for good practice. It is suggested that of central importance is the need for higher education institutions and practice teachers to work together in identifying students causing concern at an early stage in their studies, based on both objective and subjective observations, and to have in place documented procedures to be followed when such situations arise.

Parental factors affecting respiratory function during the first year of life

In a prospective, longitudinal, population-based cohort study of familial and environmental influences on the development of wheezing respiratory illness in early childhood, we identified infant length, weight, gender, and exposure to maternal cigarette smoking as significant determinants of lung function during the first year of life. A cohort of 237 infants (106 females: 131 males) was evaluated, and 496 lung function measurements were made between the ages of 1-12 months. Respiratory function was assessed using the rapid thoracic compression technique to obtain maximum expiratory flow at functional residual capacity (V'maxFRC). Parental history of asthma and smoking habits during pregnancy were obtained by questionnaire. Data were analyzed using a longitudinal random effects model. Infants with a parental history of asthma and/or in utero passive smoke exposure were compared to a reference group of infants who had no parental history of asthma and in whom neither parent smoked pre- or postnatally. Boys were found to have a consistently lower V'maxFRC (-21.05 mL.s(-1)) throughout the first year of life in comparison to girls (P < 0.05). Maternal smoking during pregnancy was associated with a lower V'maxFRC in both genders in comparison to unexposed infants (P < 0.05). V'maxFRC was unaffected by parental history of asthma. Gender-specific normative equations for V'maxFRC throughout the first year of life were derived for the infant cohort as a whole and also for subgroups of infants, based on parental asthma and smoking history. We conclude that lung function during the first year of life differs between genders and is adversely affected by in utero passive tobacco smoke exposure. Gender-specific predictive equations for V'maxFRC should be used during infancy.

The association between early life lung function and wheezing during the first 2 yrs of life

Reports have suggested that certain infants are predisposed to wheezing in the first 2 yrs of life due to abnormal lung function, prior to the first wheezing illness. The authors investigated the association between infant lung function and wheeze during the first 2 yrs of life. A cohort of 253 infants was evaluated. Respiratory function assessment was performed at 1, 6, and 12 months of age. Parental history of asthma, atopy, and maternal antenatal smoking habits were recorded. An infant was identified as having wheezed on the basis of parental report and, where possible, physician diagnosis. One hundred and sixty infants (63%) had complete diary and questionnaire information on wheeze available for analysis. Of these: 79 infants (50%) had never wheezed (NW) during the first 2 yrs of life and 81 had reported wheeze (W) (50%). Of those with a report of wheeze, the distribution through the first 2 yrs of life was; 28 during the first year of life only (Y1), 21 in the second year of life only (Y2), and 32 wheezed in both the first and second years of life (Y1&2). At the age of 1 month, prior to any lower respiratory illness, the W group had impaired lung function in comparison to the NW group. In Y1 infants, the neonatal lung function differences resolved by 12 months of age. In Y2 and Y1&2 infants lung function differences persisted throughout the first year of life. Prevalence of parental asthma and maternal antenatal smoking was increased in the W group p=0.001, p=0.008, respectively), in comparison to the NW infants. Maternal antenatal smoking prevalence was increased in the Y2 and Y1&2 infants in comparison to the NW group (p=0.04), (p=0.01), respectively. Wheezing during the first year of life is often a transient condition which improves with time. It appears to be related to early life reduced small airway calibre. Wheezing that begins or persists into the second year of life is usually associated with a different abnormality of the airways. Commencement or persistence of wheeze into the second year of life may be part of the clinical entity recognized as asthma.

The effect of inhaled adrenaline on lung function of recurrently wheezy infants less than 18 months old

Inhaled bronchodilators have been shown not to improve lung function in infants with wheeze. This observation has led to the suggestion that airway wall edema may be more important than bronchoconstriction in infants with airway narrowing. Inhaled adrenaline is used to relieve upper airway edema in children with croup and has been demonstrated to improve clinical scores and lower pulmonary resistance in some infants with wheeze associated with bronchiolitis. The aim of the present study was to examine the effect of inhaled adrenaline on lung function in a group of infants with recurrent wheeze. Eleven infants aged 10 to 18 months with a history of recurrent wheeze were studied during an asymptomatic interval. Respiratory function was assessed (1) by measuring maximal expiratory flow at functional residual capacity (VmaxFRC) during a forced partial expiratory maneuver and (2) by measuring conductance of the respiratory system (Grs) using a single expiratory occlusion technique. Following baseline measurements, the infants received 0.5 mg/kg adrenaline by nebulizer and serial lung function tests were repeated at 5 min intervals. Ten infants had abnormal baseline lung function (median VmaxFRC 44.2% predicted; median Grs 34% predicted). Using a random effects model, VmaxFRC and Grs declined significantly at 10 and 5 min after adrenaline, respectively. No significant improvements from baseline were observed in either measurement for up to 30 min following adrenaline delivery. It is concluded that inhaled adrenaline did not relieve airways obstruction in this group of asymptomatic infants with recurrent wheeze.

Lung function, airway responsiveness, and respiratory symptoms before and after bronchiolitis

Acute viral respiratory illness during infancy has been implicated as a precursor for subsequent lower respiratory morbidity in childhood. A prospective, longitudinal study of respiratory function, airway responsiveness, and lower respiratory illness during early childhood was performed in a cohort of 253 healthy infants to characterise those who experienced bronchiolitis. Seventeen infants (7% of the cohort), were given a diagnosis of bronchiolitis during the first two years of life with two (1%) requiring hospital admission. Seventy one per cent of those infants with bronchiolitis had a family history of atopy, 53% of asthma, and 29% had a mother who smoked cigarettes. These family history characteristics in this group with bronchiolitis were not different from the rest of the cohort. There were also no differences in the number of older siblings, the number breast fed, the duration of breast feeding, or socioeconomic status of the families between those that did and did not get bronchiolitis. Respiratory function was assessed at 1, 6, and 12 months of age. Maximum flow at functional residual capacity (VmaxFRC) was measured using the rapid thoracic compression technique. Resistance (Rrs) and size corrected compliance (Crs/kg) were obtained from a single brief occlusion at end inspiration. Airway responsiveness was assessed by histamine inhalation challenge and the provocation concentration of histamine resulting in a 40% fall on VmaxFRC from baseline (PC40) was determined. Respiratory measurements were ranked into terciles to assess the distribution of infants who developed bronchiolitis through the cohort. Cough and wheeze were noted to be frequent before the episode of bronchiolitis. This study has demonstrated that infants who develop bronchiolitis have evidence of pre-existing reduced respiratory function and lower respiratory symptoms. It is proposed that bronchiolitis, although potentially contributory, is not usually causative of subsequent lower respiratory morbidity.

Flow limitation during tidal expiration in symptom-free infants and the subsequent development of asthma

During a longitudinal study of lung function and airway responsiveness in a cohort of healthy infants, we identified a subgroup of symptom-free infants at the age of 1 month with flow limitation during tidal expiration. We report a 2-year follow-up of 252 infants who were first studied at 1 month of age. Maximal flow at functional residual capacity (VmaxFRC) was measured from a forced expiratory flow-volume curve by the rapid thoracic compression technique. The pattern of tidal breathing was assessed with the ratio of the time to reach maximal expiratory flow during expiration to the total expiratory time (Tme/Te ratio). Histamine inhalation challenge was used to determine the level of airway responsiveness. Compliance and resistance of the total respiratory system were measured from a passive expiration after occlusion at end inspiration. Data regarding the family history of asthma, atopy, and parental smoking were obtained by questionnaire. Flow limitation was considered present when the forced expiratory flow did not exceed tidal flow at functional residual capacity. Nineteen infants were identified with flow limitation at 5 weeks of age; all had a family history of asthma, atopy, and/or parental smoking. These 19 infants were compared with 35 infants with no family history of asthma or parental smoking and 38 gender-, history-, and age-matched control infants without flow limitation during tidal expiration. At the age of 1 month, the flow-limited group had reduced VmaxFRC, Tme/Te, and respiratory compliance and increased respiratory resistance. At 6 and 12 months of age, although no longer flow limited, these infants still had significantly reduced lung function and increased airway responsiveness. Flow limitation in early life was also significantly associated with the development of physician-diagnosed asthma by the age of 2 years (odds ratio, 7.4; 95% confidence interval, 1.4 to 35.2). Infants with abnormal lung function soon after birth may have a genetic predisposition to asthma or other airway abnormalities that predict the risk of subsequent lower respiratory tract illness.

Syntax PAL: a system to improve the written syntax of language-impaired users

In our work with children who have difficulty with spelling or with the physical action of writing, we have found a number of children who also have difficulty with written grammar. As an extension of PAL, an existing predictive spelling and typing aid, we have developed a writing aid to help these children with sentence construction. The enhanced system uses the syntax of the initial part of a sentence to enhance the position in the prediction list of syntactically correct words. It was postulated that this would discourage the use of incorrect syntax and encourage the use of correct syntax. In two case studies, the use of Syntax PAL significantly improved the quality and quantity of one child's written output, but had little effect on the other child's work.

Bronchial responsiveness and lung function in recurrently wheezy infants

Although most wheezy infants are considered asthmatic, they generally respond poorly to antiasthma treatment, and there is inadequate knowledge about the pathologic mechanisms that cause wheezing at this age. The aim of this study was to determine whether the strong association between wheezing and bronchial responsiveness (BR) seen in older subjects was also present in infants. We compared BR with inhaled histamine in 19 recurrently wheezy infants with a group of age-, height-, weight-, and sex-matched control infants. Maximal flow at FRC (VmaxFRC) was determined from partial expiratory flow-volume curves generated using the "squeeze" technique. Histamine was delivered during 1 min of tidal breathing in doubling concentrations from 0.125 g/L to a maximum of 8 g/L or until VmaxFRC fell by 40% (PC40). The median baseline VmaxFRC for the wheezy infants was 100.0 ml/s compared with 182.0 ml/s for the control infants (p less than 0.01). However, there was no significant difference in the PC40 between the two groups (2.1 versus 2.3 g/L).

Measurement of platelet-associated IgG in animal models of immune and nonimmune thrombocytopenia

Platelet-associated IgG (PAIgG) is elevated in idiopathic thrombocytopenic purpura (ITP), but it also is elevated in other thrombocytopenic disorders traditionally considered to be nonimmune. Consequently it is possible that elevated PAIgG is a nonspecific finding secondary to thrombocytopenia. To study this issue we developed a rabbit model of immune and nonimmune mediated thrombocytopenia. The mechanism of the thrombocytopenia was validated by platelet survival studies. Immune thrombocytopenia was produced by injection of antirabbit platelet serum that was raised in guinea pigs. Nonimmune aregenerative thrombocytopenia was produced by irradiation of the animals; nonimmune consumptive thrombocytopenia was produced by injection of adenosine diphosphate (ADP). PAIgG was measured in a direct binding assay using 125I-labeled staphylococcal protein A (SpA). Washed platelets from normal, nonthrombocytopenic rabbits bound an average of 81 molecules of SpA per platelet (81 +/- 168, mean +/- 2 SD, n = 39). Infusion of the antiplatelet antiserum produced thrombocytopenia with a rise in PAIgG that was closely correlated with the level of PAIgG (r = 0.86, n = 12). The thrombocytopenia was consumptive, as shown by a very short platelet life span using 111In-labeled platelets. In contrast, both nonimmune thrombocytopenic states resulted in an equal or greater drop in the platelet count but no change in the level of PAIgG. The animals with aregenerative thrombocytopenia had normal or only moderately reduced platelet life spans; however, in every animal the level of PAIgG was not different from the nonthrombocytopenic controls, irrespective of the platelet count. Similarly, the level of PAIgG was unchanged in those rabbits with nonimmune consumptive thrombocytopenia following infusion of ADP (82 +/- 55 molecules of SpA per platelet, mean +/- SD, n = 6). These studies indicate that elevated PAIgG is a specific finding of immune thrombocytopenia and is not secondary to thrombocytopenia itself. Indirectly these results support our hypothesis that immune mechanisms contribute to more thrombocytopenic disorders than was once thought likely.