Randomized double-blind trial of amifostine versus placebo for radiation-induced xerostomia in patients with head and neck cancer

INTRODUCTION

The role of the radioprotector amifostine in ameliorating radiotherapy side effects in head and neck squamous cell carcinoma (HNSCC) is controversial. This trial aimed to determine whether pretreatment with amifostine reduced the incidence of Radiation Therapy Oncology Group grade ≥2 acute and late xerostomia in patients receiving definitive or adjuvant radiotherapy for HNSCC, without reducing tumour control or survival.

METHODS

Between 14 September 2001 and 8 November 2004, 44 Royal Adelaide Hospital patients were randomized double-blind to receive amifostine (200 mg/m² IV) or placebo (normal saline IV) 5 days/week, prior to standard radiotherapy (60-70 Gy), each having ≥75% of the parotids treated to ≥40 Gy. Side effects were assessed weekly during treatment, at 3 and 5 months after radiotherapy, then every 6 months until disease progression or death.

RESULTS

The accrual target was 200 patients over 4-5 years, but the trial closed prematurely when only 44 patients had been randomized after 3 years. Of 41 evaluable patients, 80% (16/20) in the amifostine arm had grade ≥2 acute radiation salivary toxicity versus 76% (16/21) in the placebo arm (P = 1.00). The rate of grade ≥2 late radiation salivary toxicity at 12 months was 66% in the amifostine arm and 82% in the placebo arm (estimated hazard ratio 1.61, 95% confidence interval 0.74-3.49, P = 0.22). Other toxicities tended to be worse in the amifostine arm: acute grade 3-4 skin 35% vs 5% and mucous membrane 40% vs 5%; grade ≥2 vomiting 35% vs 5%, hypocalcaemia 25% vs 5% and fatigue 85% vs 33%, with only the latter retaining statistical significance after adjusting for multiple comparisons. There were no significant differences in failure-free (P = 0.70) or overall survival (P = 0.86), with estimated 4-year rates of 48% vs 54% and 49% vs 59% for the amifostine vs placebo arms respectively.

CONCLUSION

There was no clear evidence that pretreatment with amifostine made any difference to the incidence of grade ≥2 acute or late xerostomia. Other toxicity tended to be more severe with amifostine. There was no effect on failure-free or overall survival. Acknowledging the low statistical power, these results do not support the use of IV amifostine pre-radiotherapy in HNSCC.

How do the two visual streams interact with each other?

The current consensus divides primate cortical visual processing into two broad networks or "streams" composed of highly interconnected areas (Milner and Goodale 2006, 2008; Goodale 2014). The ventral stream, passing from primary visual cortex (V1) through to inferior parts of the temporal lobe, is considered to mediate the transformation of the contents of the visual signal into the mental furniture that guides memory, recognition and conscious perception. In contrast the dorsal stream, passing from V1 through to various areas in the posterior parietal lobe, is generally considered to mediate the visual guidance of action, primarily in real time. The brain, however, does not work through mutually insulated subsystems, and indeed there are well-documented interconnections between the two streams. Evidence for contributions from ventral stream systems to the dorsal stream comes from human neuropsychological and neuroimaging research, and indicates a crucial role in mediating complex and flexible visuomotor skills. Complementary evidence points to a role for posterior dorsal-stream visual analysis in certain aspects of 3-D perceptual function in the ventral stream. A series of studies of a patient with visual form agnosia has been instrumental in shaping our knowledge of what each stream can achieve in isolation; but it has also helped us to tease apart the relative dependence of parietal visuomotor systems on direct bottom-up visual inputs versus inputs redirected via perceptual systems within the ventral stream.

The nature and limits of orientation and pattern processing supporting visuomotor control in a visual form agnosic

Abstract We have previously reported that a patient (DF) with visual form agnosia shows accurate guidance of hand and finger movements with respect to the size, orientation, and shape of the objects to which her movements are directed. Despite this, she is unable to indicate any knowledge about these object properties. In the present study, we investigated the extent to which DF is able to use visual shape or pattern to guide her hand movements. In the first experiment, we found that when presented with a stimulus aperture cut in the shape of the letter T, DF was able to guide a T-shaped form into it on about half of the trials, across a range of different stimulus orientations. On the remaining trials, her responses were almost always perpendicular to the correct Orientation. Thus, the visual information guiding the rotation of DF's hand appears to be limited to a single orientation. In other words, the visuomotor transformations mediating her hand rotation appear to be unable to combine the orientations of the stem and the top of the T, although they are sensitive to the orientation of the element(s) that comprise the T. In a second experiment, we examined her ability to use different sources of visual information to guide her hand rotation. In this experiment, DF was required to guide the leading edge of a hand-held card onto a rectangular target positioned at dHerent orientations on a flat surface. Here the orientation of her hand was determined primarily by the predominant orientation of the luminance edge elements present in the stimulus, rather than by information about orientation that was conveyed by nonluminance boundaries. Little evidence was found for an ability to use contour boundaries defined by Gestalt principles of grouping (good continuation or similarity) or "nonaccidental" image properties (colinearity) to guide her movements. We have argued elsewhere that the dorsal visual pathway from occipital to parietal cortex may underlie these preserved visuomotor skills in DF. If so, the limitations in her ability to use different kinds of "pattern" information to guide her hand rotation suggest that such information may need to be transmitted from the ventral visual stream to these parietal areas to enable the full range of prehensive acts in the intact individual.

Is visual processing in the dorsal stream accessible to consciousness?

There are two highly interconnected clusters of visually responsive areas in the primate cortex. These two clusters have relatively few interconnections with each other, though those interconnections are undoubtedly important. One of the two main clusters (the dorsal stream) links the primary visual cortex (V1) to superior regions of the occipito-parietal cortex, while the other (the ventral stream) links V1 to inferior regions of the occipito-temporal cortex. According to our current understanding of the functional anatomy of these two systems, the dorsal stream's principal role is to provide real-time 'bottom-up' visual guidance of our movements online. In contrast, the ventral stream, in conjunction with top-down information from visual and semantic memory, provides perceptual representations that can serve recognition, visual thought, planning and memory offline. In recent years, this interpretation, initially based chiefly on studies of non-human primates and human neurological patients, has been well supported by functional MRI studies in humans. This perspective presents empirical evidence for the contention that the dorsal stream governs the visual control of movement without the intervention of visual awareness.

Phase II study of autologous stem cell transplant using busulfan-melphalan chemotherapy-only conditioning followed by interferon for relapsed poor prognosis follicular non-Hodgkin lymphoma

Alpha interferon has proven efficacy in prolonging remissions in patients with follicular non-Hodgkin lymphoma (NHL) when given concurrently with or after conventional-dose anthracycline-based chemotherapy, but there are limited data on its use after myeloablative conditioning. We prospectively evaluated the toxicity and efficacy of interferon given thrice weekly for up to 5 years post-engraftment in patients with relapsed follicular NHL undergoing autologous stem cell transplant using busulfan-melphalan conditioning. Thirty-seven patients were enrolled in this Australasian Leukaemia & Lymphoma Group study and transplanted between 1995 and 1999. Only one patient had received prior rituximab. Two patients died of transplant-related toxicity; 28 of the remainder commenced interferon, but it was discontinued prematurely in most patients due to toxicity (mainly fatigue and depression) or relapse. While the majority of patients (29/36 evaluable: 81%) achieved a complete remission based on clinical and CT scan criteria post-transplant, most relapsed relatively early, with a median progression-free survival of 2.4 years. The overall survival at 7 years was 49%. Eight patients (22%), however, remain alive a median of 9.3 years post-transplant, having never relapsed, and another six patients (16%) remain alive in durable remission after salvage therapy. These results demonstrate that interferon is poorly tolerated post-autograft and hence is unlikely to positively contribute to patient outcome. Long-term follow-up demonstrates that autografting may result in durable remissions in a meaningful minority of patients with relapsed follicular NHL.

Prospective study of percutaneous endoscopic gastrostomy tubes versus nasogastric tubes for enteral feeding in patients with head and neck cancer undergoing (chemo)radiation

BACKGROUND

Percutaneous endoscopic gastrostomy (PEG) tubes have largely replaced nasogastric tubes (NGTs) for nutritional support of patients with head and neck cancer undergoing curative (chemo) radiotherapy without any good scientific basis.

METHODS

A prospective study was conducted to compare PEG tubes and NGTs in terms of nutritional outcomes, complications, patient satisfaction, and cost.

RESULTS

There were 32 PEG and 73 NGT patients. PEG patients sustained significantly less weight loss at 6 weeks post-treatment (median 0.8 kg gain vs 3.7 kg loss, p < .001), but had a high insertion site infection rate (41%), longer median duration of use (146 vs 57 days, p < .001), and more grade 3 dysphagia in disease-free survivors at 6 months (25% vs 8%, p = .07). Patient self-assessed general physical condition and overall quality of life scores were similar in both groups. Overall costs were significantly higher for PEG patients.

CONCLUSION

PEG tube use should be selective, not routine, in this patient population.

Separate processing of texture and form in the ventral stream: evidence from FMRI and visual agnosia

Real-life visual object recognition requires the processing of more than just geometric (shape, size, and orientation) properties. Surface properties such as color and texture are equally important, particularly for providing information about the material properties of objects. Recent neuroimaging research suggests that geometric and surface properties are dealt with separately within the lateral occipital cortex (LOC) and the collateral sulcus (CoS), respectively. Here we compared objects that differed either in aspect ratio or in surface texture only, keeping all other visual properties constant. Results on brain-intact participants confirmed that surface texture activates an area in the posterior CoS, quite distinct from the area activated by shape within LOC. We also tested 2 patients with visual object agnosia, one of whom (DF) performed well on the texture task but at chance on the shape task, whereas the other (MS) showed the converse pattern. This behavioral double dissociation was matched by a parallel neuroimaging dissociation, with activation in CoS but not LOC in patient DF and activation in LOC but not CoS in patient MS. These data provide presumptive evidence that the areas respectively activated by shape and texture play a causally necessary role in the perceptual discrimination of these features.

Relation of exhaled nitric oxide levels to development of bronchopulmonary dysplasia

OBJECTIVE

To test the hypothesis that exhaled nitric oxide levels on day 28 and changes in exhaled nitric oxide levels in the neonatal period would differ according to whether infants developed bronchopulmonary dysplasia (BPD) and its severity.

DESIGN

Prospective observational study.

SETTING

Tertiary neonatal intensive care unit.

PATIENTS

80 infants (median gestational age 28, range 24-32 weeks), 46 of whom developed BPD.

INTERVENTIONS

Exhaled nitric oxide measurements were attempted on days 3, 5, 7, 14, 21 and 28.

MAIN OUTCOME MEASURES

BPD (oxygen dependency at 28 days), mild BPD (oxygen dependent at 28 days, but not 36 weeks postmenstrual age (PMA)); moderate BPD (oxygen dependent at 36 weeks PMA) and severe BPD (respiratory support dependent at 36 weeks PMA).

RESULTS

On day 28, exhaled nitric oxide levels were higher in infants with BPD compared to those without BPD (p<0.001) and there was a linear trend in exhaled nitric oxide results as BPD severity increased (p = 0.006). No significances in the change in exhaled nitric oxide levels over the neonatal period were found between the four groups.

CONCLUSION

Exhaled nitric oxide levels are raised in infants with established BPD, particularly in those developing moderate or severe BPD, and may reflect ongoing inflammation.

Randomized study of percutaneous endoscopic gastrostomy versus nasogastric tubes for enteral feeding in head and neck cancer patients treated with (chemo)radiation

Percutaneous endoscopic gastrostomy (PEG) tubes have largely replaced nasogastric tubes (NGT) for nutritional support of patients with head and neck cancer undergoing curative (chemo)radiotherapy without any good scientific basis. A randomized trial was conducted to compare PEG tubes and NGT in terms of nutritional outcomes, complications, patient satisfaction and cost. The study was closed early because of poor accrual, predominantly due to patients' reluctance to be randomized. There were 33 patients eligible for analysis. Nutritional support with both tubes was good. There were no significant differences in overall complication rates, chest infection rates or in patients' assessment of their overall quality of life. The cost of a PEG tube was 10 times that of an NGT. The duration of use of PEG tubes was significantly longer, a median 139 days compared with a median 66 days for NGT. We found no evidence to support the routine use of PEG tubes over NGT in this patient group.

A phase I trial of Capecitabine+Gemcitabine with radical radiation for locally advanced pancreatic cancer

Standard chemoradiotherapy with infusional 5FU for locally advanced pancreatic cancer (LAPC) has limited efficacy in this disease. The combination of Capecitabine (Cap) and Gemcitabine (Gem) are synergistic and are potent radiosensitisers. The aim of this phase I trial was thus to determine the highest administered dose of the Cap plus Gem combination with radical radiotherapy (RT) for LAPC. Patients had LAPC, adequate organ function, ECOG PS 0–1. During RT, Gem was escalated from 20–50 mg m⁻² day⁻¹ (twice per week), and Cap 800–2000 mg m⁻² day⁻¹ (b.i.d, days 1–5 of each week). Radiotherapy 50.4 Gy/28 fractions/5.5 weeks, using 3D-conformal techniques. Three patients were entered to each dose level (DL). Dose-limiting toxicity(s) (DLTs) were based on treatment-related toxicities. Twenty patients were accrued. Dose level (DL) 1: Cap/Gem; 800/20 mg m⁻² day⁻¹ (3 patients), DL2: 1000/20 (12 patients), DL3: 1300/30 (5 patients). Dose-limiting toxicities were observed in DL3; grade 3 dehydration (1 patient) and grade 3 diarrhoea and dehydration (1 patient). Dose level 2 was the recommend phase 2 dose. Disease control rate was 75%: PR=15%, SD=60%. Median overall survival was 11.2 months. The addition of Cap and Gem to radical RT was feasible and active and achieved at relatively low doses.

Clinical impact of, and prognostic stratification by, F-18 FDG PET/CT in head and neck mucosal squamous cell carcinoma

BACKGROUND

The aim of this study was to determine prospectively the incremental value of positron emission tomography/computed tomography (PET/CT) over conventional assessment (clinical examination and CT/MRI imaging).

METHODS

All patients undergoing (18)F-fluorodeoxyglucose (FDG)-PET/CT for primary head and neck mucosal squamous cell carcinoma between January 2002 and December 2003 (inclusive) were included in this study provided they had undergone contemporaneous conventional assessment of the head and neck region and had 12 months minimum follow-up.

RESULTS

Seventy-six patients underwent 100 PET/CT scans. The majority of patients (74%) were treated with definitive (chemo)radiotherapy. Median follow-up time was 28 months. PET/CT led to a TNM classification alteration in 34% (12/35), a change in radiotherapy planning technique and/or dose in 29% (10/35), and altered treatment response assessment in 43% (13/30). A complete metabolic response was predictive of overall survival (p = .037).

CONCLUSION

Our results support incorporation of PET/CT into the management paradigm of head and neck mucosal squamous cell carcinoma.

Synchronized mechanical ventilation for respiratory support in newborn infants

BACKGROUND

During synchronized mechanical ventilation, positive airway pressure and spontaneous inspiration coincide. If synchronous ventilation is provoked, adequate gas exchange should be achieved at lower peak airway pressures, potentially reducing baro/volutrauma, air leak and bronchopulmonary dysplasia. Synchronous ventilation can potentially be achieved by manipulation of rate and inspiratory time during conventional ventilation and employment of patient triggered ventilation.

OBJECTIVES

To compare the efficacy of: (i) synchronized mechanical ventilation, delivered as high frequency positive pressure ventilation (HFPPV) or patient triggered ventilation - assist control ventilation (ACV) or synchronous intermittent mandatory ventilation (SIMV)) with conventional ventilation (CMV) (ii) different types of triggered ventilation (ACV, SIMV, pressure regulated volume control ventilation (PRVCV) and SIMV plus pressure support (PS) SEARCH STRATEGY: Searches from 1985-2007 of the Cochrane Central Register of Controlled Trials (CENTRAL, The Cochrane Library, Issue 2, 2007),Oxford Database of Perinatal Trials, MEDLINE, previous reviews, abstracts and symposia proceedings; hand searches of journals in the English language and contact with expert informants.

SELECTION CRITERIA

Randomised or quasi-randomised clinical trials comparing synchronized ventilation delivered as high frequency positive pressure ventilation (HFPPV) or triggered ventilation (ACV/SIMV) to conventional mechanical ventilation (CMV) in neonates. Randomised trials comparing different triggered ventilation modes (ACV, SIMV, SIMV plus PS and PRVCV) in neonates.

DATA COLLECTION AND ANALYSIS

Data regarding clinical outcomes including mortality, air leaks (pneumothorax or pulmonary interstitial emphysema (PIE)), severe intraventricular haemorrhage (grades 3 and 4), bronchopulmonary dysplasia (BPD) (oxygen dependency beyond 28 days), moderate/severe BPD (oxygen/respiratory support dependency beyond 36 weeks postmenstrual age (PMA) and duration of weaning/ventilation. Four comparisons were made: (i) HFPPV vs. CMV; (ii) ACV/SIMV vs. CMV; (iii) ACV vs. SIMV or PRVCV vs. SIMV (iv) SIMV plus PS vs. SIMV. Data analysis was conducted using relative risk for categorical outcomes, weighted mean difference for outcomes measured on a continuous scale.

MAIN RESULTS

Fourteen studies were eligible for inclusion. The meta-analysis demonstrates that HFPPV compared to CMV was associated with a reduction in the risk of air leak (typical relative risk for pneumothorax was 0.69, 95% CI 0.51, 0.93). ACV/SIMV compared to CMV was associated with a shorter duration of ventilation (weighted mean difference -34.8 hours, 95% CI -62.1, -7.4). ACV compared to SIMV was associated with a trend to a shorter duration of weaning (weighted mean difference -42.4 hours, 95% CI -94.4, 9.6). Neither HFPPV nor triggered ventilation was associated with a significant reduction in the incidence of BPD. There was a non-significant trend towards a lower mortality rate using HFPPV vs. CMV and a non-significant trend towards a higher mortality rate using triggered ventilation vs. CMV. No disadvantage of HFPPV or triggered ventilation was noted regarding other outcomes. Since the last review, two new patient triggered modes have been included: pressure regulated volume control ventilation (PRVCV) and SIMV plus pressure support. Each of these methods of ventilation has only been tested in single randomised trials with no significant advantages in important outcomes.

AUTHORS' CONCLUSIONS

Compared to conventional ventilation, benefit is demonstrated for both HFPPV and triggered ventilation with regard to a reduction in air leak and a shorter duration of ventilation, respectively. In none of the trials was complex respiratory monitoring undertaken and thus it is not possible to conclude that the mechanism of producing those benefits is by provocation of synchronized ventilation. Further trials are needed to determine whether synchronized ventilation is associated with other benefits, but optimisation of trigger and ventilator design with respect to respiratory diagnosis is encouraged before embarking on further trials. It is essential newer forms of triggered ventilation are tested in adequately powered randomised trials with long-term outcomes before they are incorporated into routine clinical practice.

Two visual systems re-viewed

The model proposed by the authors of two cortical systems providing 'vision for action' and 'vision for perception', respectively, owed much to the inspiration of Larry Weiskrantz. In the present article some essential concepts inherent in the model are summarized, and certain clarifications and refinements are offered. Some illustrations are given of recent experiments by ourselves and others that have prompted us to sharpen these concepts. Our explicit hope in writing our book in 1995 was to provide a theoretical framework that would stimulate research in the field. Conversely, well-designed empirical contributions conceived within the framework of the model are the only way for us to progress along the route towards a fully fleshed-out specification of its workings.

Patients with multiple myeloma treated with thalidomide: evaluation of clinical parameters, cytokines, angiogenic markers, mast cells and marrow CD57+ cytotoxic T cells as predictors of outcome

BACKGROUND AND OBJECTIVES

In vitro studies suggest that thalidomide has an immunoregulatory role and alters the marrow microenvironment. We assessed laboratory and clinical parameters in patients with myeloma treated with thalidomide as potential prognostic markers and looked for changes with therapy.

DESIGN AND METHODS

Seventy-five patients with relapsed/refractory myeloma received thalidomide in a phase II trial. Serial samples of platelet-poor plasma and bone marrow were tested for angiogenic cytokines including vascular endothelial growth factor (VEGF), marrow microvessel-density (MVD), mast cells and CD57+ cell expression. The effects of these parameters on response rate (RR), progression-free survival (PFS) and overall survival (OS) were analyzed.

RESULTS

Elevated baseline VEGF predicted for a superior RR (p=0.018) and PFS. Elevated CD57+ cells also predicted superior PFS (p=0.012). MVD did not predict for RR, PFS or OS, but MVD and VEGF fell significantly in responders. Multivariate analysis identified that inferior OS was associated with age >65 years (p=0.017), raised lactate dehydrogenase (p=0.001), raised hepatocyte growth factor levels (p=0.012) and low pre-treatment CD57+ cells (p<0.001).

INTERPRETATION AND CONCLUSIONS

Our findings support the suggestion that thalidomide has anti-angiogenic and immunomodulatory effects in myeloma. The preferred method for assessing angiogenesis is plasma VEGF levels and the assessment of CD57+ cells for patients with myeloma receiving novel immunomodulatory drugs should be further investigated.

Malignant ureteral obstruction: outcomes after intervention. Have things changed?

PURPOSE

We reviewed the clinical outcome for patients who underwent decompression of malignant ureteral obstruction by analyzing potential prognostic factors, technical success, complication rates and days spent in hospital.

MATERIALS AND METHODS

Retrospective analysis of 102 patients who underwent decompression for malignant ureteral obstruction from 1991 to 2003 was performed. Data on overall survival, prognostic factors, technical failure, complications and days of hospitalization after decompression were examined.

RESULTS

Median overall survival was 6.8 months (95% CI 4.8-9.3) and the overall survival rate at 12 months was 29% (95% CI 21%-39%). Univariate analyses found inferior overall survival associated with patients having metastases (p=0.041), undergoing nephrostomy (p=0.046), prior treatment for cancer (p=0.024) and diagnosis of malignant ureteral obstruction in previously established malignancy (p=0.043). After multivariate analysis poor prognostic factors were presence of metastases (p=0.020) and diagnosis of malignant ureteral obstruction in previously established malignancy (p=0.039). Unfavorable cohorts with 3 or 4 unfavorable baseline risk factors had an inferior overall survival (p=0.008) with 12-month overall survival rates of 12% to 19%. Initial decompression of malignant ureteral obstruction failed in 6% of patients (95% CI 2%-12%) and complications were experienced by 53% (95% CI 43%-63%). Patients were more likely to experience a complication if they had therapy after decompression (p=0.03). The median percentage of their remaining lifetime spent in hospital was 17.4% (range 0.21% to 100%).

CONCLUSIONS

The overall survival of patients with malignant ureteral obstruction remains poor. Prognostic factors for decreased overall survival and prolonged hospital stay have been identified. Although the technical success of decompression has improved the subsequent complication rate is still high.

Radiotherapy for low-grade gastric marginal zone lymphoma: a retrospective study

BACKGROUND

We evaluated the efficacy and toxicity of radiotherapy (RT) in patients with low-grade gastric marginal zone lymphoma.

METHODS

A retrospective review of consecutive cases of gastric marginal zone lymphoma treated by radical RT at the Peter MacCallum Cancer Centre and Radiation Oncology Victoria between January 1980 and September 2003 was carried out.

RESULTS

Eighteen patients (11 men and 7 women) were identified. The median age at commencement of RT was 65 years (range 42-84 years). Prior treatment included Helicobacter pylori eradication in 12 patients, chemotherapy in 7 and surgery in 2, whereas 2 patients had no prior therapy. The median time to progression after commencement of last treatment before RT was 4.8 months (range 0-129.4 months). The radiation fields included the stomach plus perigastric and coeliac nodes in 15 patients (83%), stomach plus spleen in 2 patients (11%) and stomach plus para-aortic nodes in 1 patient (6%). The median RT dose was 30 Gy (range 30-36 Gy) in a median 20 fractions (range 17-24 fractions). One patient required treatment interruption for acute toxicity. A complete response on post-RT biopsies was achieved in 17 of 18 patients (94%). With a median follow up of 4.5 years after RT, 3 of these 17 patients (18%) have had a recurrence. At the last follow up, 11 patients were alive in continuous complete histological remission. No late renal toxicity was identified.

CONCLUSION

Radiotherapy is an effective, well-tolerated treatment for patients with low-grade gastric marginal zone lymphoma, including those who have had prior therapy.

Intensity-modulated radiotherapy for nasopharyngeal carcinoma: Clinical correlation of dose to the pharyngo-esophageal axis and dysphagia

PURPOSE

The aim of this study was to quantify the dose delivered to the pharyngo-esophageal axis using different intensity-modulated radiation therapy (IMRT) techniques for treatment of nasopharyngeal carcinoma and to correlate this with acute swallowing toxicity.

METHODS AND MATERIALS

The study population consisted of 28 patients treated with IMRT between February 2002 and August 2005: 20 with whole field IMRT (WF-IMRT) and 8 with IMRT fields junctioned with an anterior neck field with central shielding (j-IMRT). Dose to the pharyngo-esophageal axis was measured using dose-volume histograms. Acute swallowing toxicity was assessed by review of dysphagia grade during treatment and enteral feeding requirements.

RESULTS

The mean pharyngo-esophageal dose was 55.2 Gy in the WF-IMRT group and 27.2 Gy in the j-IMRT group, p < 0.001. Ninety-five percent (19/20) of the WF-IMRT group developed Grade 3 dysphagia compared with 62.5% (5/8) of the j-IMRT group, p = 0.06. Feeding tube duration was a median of 38 days for the WF-IMRT group compared with 6 days for the j-IMRT group, p = 0.04.

CONCLUSIONS

Clinical vigilance must be maintained when introducing new technology to ensure that unanticipated adverse effects do not result. Although newer planning systems can reduce the dose to the pharyngo-esophageal axis with WF-IMRT, the j-IMRT technique is preferred at least in patients with no gross disease in the lower neck.

Prognostic factors predictive of response and survival to a modified FOLFOX regimen: importance of an increased neutrophil count

PURPOSE

The aim of this study was to identify prognostic indicators of survival and response in a homogeneous population of chemotherapy-naive patients treated with oxaliplatin as part of 3 successive trials.

PATIENTS AND METHODS

Patient data were derived from 3 successive phase II trials evaluating modifications of the FOLFOX4 (oxaliplatin/5-fluorouracil/leucovorin) regimen. Clinical and laboratory prognostic factors were identified from the literature. Multifactor analyses stratified by treatment cohort were performed to identify independent prognostic factors for progression-free survival (PFS), overall survival (OS), and response rate.

RESULTS

One hundred thirty-four patients were enrolled across all 3 studies. Reduced PFS (n = 128) was associated with patients with the following characteristics: no previous surgery (P = 0.003); previous adjuvant chemotherapy (P = 0.015); > 1 organ involvement (P = 0.001); baseline absolute neutrophil count (ANC) > or = upper limit of normal (P = 0.001); and time from diagnosis to metastases < 9 months (P = 0.043). Poor OS (n = 128) was associated with patients with the following characteristics: performance status > 1 (P < 0.001); > 1 organ involvement (P = 0.018); and baseline ANC > or = upper limit of normal (P < 0.001). Response rate was related to previous surgery (P = 0.017) and performance status (P = 0.02).

CONCLUSION

This analysis has identified the additional prognostic importance of an increased ANC for PFS and OS. Further consideration needs to be given to include markers of systemic inflammation such as ANC as well as relevant cytokine levels in a larger cohort of identically treated patients.

A phase I/II trial of celecoxib with chemotherapy and radiotherapy in the treatment of patients with locally advanced oesophageal cancer

BACKGROUND

The study's aim was to determine the maximum tolerated dose (MTD) of celecoxib combined with chemoradiotherapy (CRT) for locally advanced oesophageal cancer (OC).

METHODS

CRT comprised of 5FU (1000 mg/m(2)/day, days 1-4, weeks 1 & 5), cisplatin (75 mg/m(2), days 1 & 29) and radiotherapy (50 Gy in 25 fractions or 50.4 Gy in 28 fractions). Celecoxib was given daily during CRT at one of five doses (200 mg bd to 600 mg bd). Three to six patients were assigned per dose.

RESULTS

Thirteen patients were recruited before trial closure due to external safety concerns regarding celecoxib. Median follow up was 17 months (95% CI 9 - >39). The highest administered dose was 400 mg bd (n=4) with one dose-limiting toxicity at this level: grade 3 rash. Five (38%) and 8(62%) patients had grade 3 non-haematological and haematological toxicities respectively. No grade 4 toxicities occurred. Radiological response rate was 54% (n=7: all CR). Six patients had resection with one pathological CR. Median progression-free and overall survival were 8.8 (95% CI 5.1 - >24.8) and 19.6 months (95% CI 7.3 - >39) respectively.

CONCLUSIONS

A MTD was not reached. The regimen was tolerable, indicating that celecoxib can be safely administered with CRT for locally advanced OC.

Relationship of Hepatic Functional Imaging to Irinotecan Pharmacokinetics and Genetic Parameters of Drug Elimination

Purpose

The marked variability of irinotecan (Ir) clearance warrants individualized dosing based on hepatic drug handling. The aims of this trial were to identify parameters from functional hepatic nuclear imaging (HNI) that correlate with (1) Ir pharmacology, and (2) single-nucleotide polymorphisms (SNPs) for the ABCB1 (P-glycoprotein) and UGT-1A1 genes, known to influence Ir handling.

Methods

Patients underwent genotyping for ABCB1 SNPs and UTUGT-1A1*28 carriage and HNI with 99mTc-DIDA (acetanilidoiminodiacetic acid)/ 99mTc-DISIDA (disofenin) and MIBI (99mTc-sestamibi) scans, probes for biliary transport proteins ABCC1 and -2, and ABCB1 function. HNI data were analyzed by noncompartmental and deconvolutional analysis to provide hepatic extraction and biliary excretion parameters. Patients received Ir, fluorouracil, and folinic acid using a weekly ×2, every-3-weeks schedule. Plasma was taken for Ir and SN-38 analysis on day 1, cycle 1.

Results

Of the 21 patients accrued, Ir pharmacokinetics data were obtained from 16 patients. 99mTc-DIDA/DISIDA percent retention at 1 hour (1-hour RET) correlated to baseline serum bilirubin (P = .008). Both 99mTc-DIDA/DISIDA and MIBI 1-hour RET correlated with SN-38 area under the curve (AUC; P < .01). On multiple regression analysis, SN-38 AUC = −215 + 18.68 × bilirubin + 4.27 × MIBI 1-hour RET (P = .009, R2 = 44.2%). HNI parameters did not correlate with Ir toxicity or UGT1A1*28 carriage. MIBI excretion was prolonged in patients with the ABCB1 exon 26 TT variant allele relative to wild-type (P = .015).

Conclusion

Functional imaging of hepatic uptake and excretory pathways may have potential to predict Ir pharmacokinetics. Evaluation of a larger cohort as well as polymorphisms in other biliary transporters and UGT1A1 alleles is warranted.

A multicenter phase II trial of thalidomide and celecoxib for patients with relapsed and refractory multiple myeloma

Preclinical data indicates that cyclooxygenase-2 (COX-2) inhibition impairs plasma cell growth and potentially synergizes with thalidomide. We performed a trial in previously treated patients with myeloma using thalidomide up to a maximum dose of 800 mg/d with celecoxib (400 mg bid). Outcomes were compared with a prior trial of thalidomide. Sixty-six patients with median age of 67 (range, 43-85) received a median dose of thalidomide and celecoxib of 400 and 800 mg/d, respectively, with median durations of treatment of 27 and 13 weeks, respectively. The most common toxicities associated with premature discontinuation of celecoxib (n = 30 of 53, 57%) were fluid retention and deterioration of renal function. Overall response rate (RR) was 42% and with 20 months median follow-up; the actuarial median progression-free survival and overall survival were 6.8 and 21.4 months, respectively. Unlike our prior study, age >65 years was not predictive of inferior RR due to improvement in RR in older patients with the combination (37% versus 15%, P = 0.08). The RR was superior in patients who received a total dose of celecoxib exceeding 40 g in the first 8 weeks of therapy (62% versus 30%, P = 0.021). Progression-free survival and overall survival were also improved. Other predictors for inferior progression-free survival were age >65 years (P = 0.016) and elevated beta(2)-microglobulin (P = 0.017). This study provides evidence that the addition of high-dose celecoxib adds to the antimyeloma activity of thalidomide but this comes with unacceptable toxicity. Future studies should use newer COX-2 inhibitors with thalidomide, or their respective derivatives.

Parotid-sparing radiotherapy: does it really reduce xerostomia?

AIMS

Parotid-sparing radiotherapy (PSRT) was introduced for patients with selected head and neck cancer requiring bilateral upper-neck irradiation at our centre in 2000. The aim of this study was to compare the subjective degree of xerostomia in patients treated with PSRT between January 2000 and June 2003 with patients treated using conventional techniques (radiotherapy) over the same period.

MATERIALS AND METHODS

Eligible patients were required to have completed treatment 6 months previously and be recurrence-free at the time of interview. PSRT was defined as conformal radiotherapy, in which the mean dose to at least one parotid gland was 33 Gy or less, as determined by the dose-volume histogram. Patients receiving radiotherapy were treated with standard parallel-opposed fields, such that both parotids received a minimum of 40 Gy. Xerostomia was assessed using a validated questionnaire containing six questions with a rating between 0 and 10. Lower scores indicated less difficulty with xerostomia.

RESULTS

Thirty-eight eligible patients treated with PSRT were identified: 25 with oropharyngeal cancer and 13 with nasopharyngeal cancer (NPC). The mean overall questionnaire score (Q1-5) for this group was 4.20 (standard error = 0.33). Forty-four patients (24 oropharyngeal, 21 NPC) treated with radiotherapy over the same period were eligible. The mean overall questionnaire score (Q1-5) for this group was 5.86 (standard error = 0.35). The difference in mean overall scores between the two groups of patients was statistically significant (P < 0.001), as were the scores for four of the six individual questions.

CONCLUSION

These results suggest that PSRT offers improved long-term xerostomia-related quality of life compared with conventional radiotherapy.

Reaching errors in optic ataxia are linked to eye position rather than head or body position

When reaching towards a visual stimulus, spatial information about the target must be transformed into an appropriate motor command. Visual information is coded initially in retinotopic coordinates, while the reaching movement ultimately requires the specification of the target position in limb-centred coordinates. It is well established that the posterior parietal cortex (PPC) plays an important role in transforming visual target information into motor commands. Lesions in the PPC can result in optic ataxia, a condition in which the visual guidance of goal-directed movements is impaired. Here, we present evidence from two patients with unilateral optic ataxia following right PPC lesions, that the pattern of reaching errors is linked to an eye-centred frame of reference. Both patients made large errors when reaching to visual targets on the left side of space, while facing and fixating straight ahead. By varying the location of fixation and the orientation of the head and body, we were able to establish that these large errors were made specifically to targets to the left of eye-fixation, rather than to the left of head-, body-, or limb-relative space. These data support the idea that visual targets for reaching movements are coded in eye-centred coordinates within the posterior parietal cortex.

Nipple aspiration and ductal lavage in women with a germline BRCA1 or BRCA2 mutation

Introduction

The aim of this study was to collect serial samples of nipple aspirate (NA) and ductal lavage (DL) fluid from women with germline BRCA1/2 mutations in order to create a biorepository for use in identifying biomarkers of breast cancer risk.

Methods

Between March 2003 and February 2005, 52 women with germline BRCA1 or BRCA2 mutations (median age 43 years, range 27 to 65 years) were scheduled for six-monthly NA, DL and venesection. DL was attempted for all NA fluid-yielding (FY) and any non-FY ducts that could be located at each visit.

Results

Twenty-seven (52%) women were postmenopausal, predominantly (19/27) from risk reducing bilateral salpingo-oophorectomy (BSO). FY ducts were identified in 60% of all women, 76% of premenopausal women versus 44% of postmenopausal (P = 0.026). Eighty-five percent of women had successful DL. Success was most likely in women with FY ducts (FY 94% versus non-FY 71% (P = 0.049). DL samples were more likely to be cellular if collected from FY ducts (FY 68% versus non-FY 43%; P = 0.037). Total cell counts were associated with FY status (FY median cell count 30,996, range 0 to >1,000,000 versus non-FY median cell count 0, range 0 to 173,577; P = 0.002). Four women (8%) had ducts with severe atypia with or without additional ducts with mild epithelial atypia; seven others had ducts with mild atypia alone (11/52 (21%) in total). Median total cell count was greater from ducts with atypia (105,870, range 1920 to >1,000,000) than those with no atypia (174, 0 to >1,000,000; P ≤ 0.001).

Conclusion

It is feasible to collect serial NA and DL samples from women at high genetic risk of breast cancer, and we are creating a unique, prospective collection of ductal samples that have the potential to be used for discovery of biomarkers of breast cancer risk and evaluate the ongoing effects of risk reducing BSO. DL cellular atypia was not predictive of a current breast cancer and longer follow up is needed to determine whether atypia is an additional marker of future breast cancer risk in this population already at high genetic risk of breast cancer.

A phase I trial of high-dose palliative radiotherapy plus concurrent weekly Vinorelbine and Cisplatin in patients with locally advanced and metastatic NSCLC

The role of concurrent chemoradiotherapy (CRT) in patients with non-small-cell lung cancer (NSCLC) unsuitable for radical therapy but who require locoregional treatment has not been defined. The aims of this phase I trial were thus to develop a novel regimen of weekly chemotherapy concurrent with high-dose palliative RT (40 Gy/20 fractions) and assess its tolerability, objective and symptomatic response rates. Eligible patients had stage I–IIIB NSCLC unsuitable for radical RT or limited stage IV disease, ECOG PS⩽1 and required locoregional therapy. Treatment was RT (40 Gy/20 fractions/5 per week) and weekly Vinorelbine plus Cisplatin escalated in six planned dose levels (DLs). At 4 weeks post-RT, patients received two cycles of Cisplatin 80 mg m⁻² day 1+Vinorelbine 25 mg m⁻² days 1, 8, 15. Dose-limiting toxicities (DLTs) were defined in the CRT phase. Disease-related symptoms were assessed by the Lung Cancer Symptom Scale. In all, 24 patients accrued, stage IIIB (n=12) and IV disease (n=10). The highest administered dose was at DL 4, Vinorelbine 30 mg m⁻²+Cisplatin 20 mg m⁻² with DLTs of grade 4 neutropenia in two of three patients. No grade 3 or 4 nonhaematological toxicities were observed. The overall radiological response rate was 65% (n=23: complete response 4% and partial response 61%) and infield FDG-PET responses were seen in 89% (n=18). There was an improvement or stabilisation of symptoms and quality of life. Dose level 3, Vinorelbine 25 mg m⁻²+Cisplatin 20 mg m⁻², is recommended for further assessment. This regimen was tolerable and produced meaningful responses for patients for whom locoregional control is required, but who are unsuitable for radical CRT.

The 'QUAD SHOT'--a phase II study of palliative radiotherapy for incurable head and neck cancer

BACKGROUND AND PURPOSE

The primary objective of this study was to estimate the rate of tumour response to a cyclical hypofractionated palliative radiotherapy regimen (QUAD SHOT) in previously untreated patients with incurable squamous cell carcinoma of the head and neck. Secondary objectives were to prospectively evaluate toxicity, quality of life (QoL) and survival in these patients.

PATIENTS AND METHODS

The QUAD SHOT consisted of 14 Gy in four fractions, given twice a day and at least 6h apart, for 2 consecutive days. This regimen was repeated at 4 weekly intervals for a further two courses if there was no tumour progression. The QoL tool used was an abbreviation of the EORTC QLQ-C30.

RESULTS

Thirty eligible patients (29 Stage IV, 20 performance status 2-3) had at least one treatment and 16 patients completed all three cycles. Sixteen patients (53%) had an objective response (2CR, 14PR) and a further seven had stable disease. Median overall survival was 5.7 months, median progression free survival was 3.1 months. The treatment was very well tolerated, with improved QoL in 11 of 25 evaluable patients (44%).

CONCLUSION

The QUAD SHOT regimen is an effective palliative treatment with minimal toxicity and a good response rate, which impacts positively on patients' QoL.

Dampened ventilatory response to added dead space in newborns of smoking mothers

BACKGROUND

Term newborns can compensate fully for an imposed dead space (tube breathing) by increasing their minute ventilation.

OBJECTIVE

To test the hypothesis that infants of smoking mothers would have an impaired response to tube breathing.

DESIGN

Prospective study.

SETTING

Perinatal service.

PATIENTS

Fourteen infants of smoking and 24 infants of non-smoking mothers (median postnatal age 37 (11-85) hours and 26 (10-120) hours respectively) were studied.

INTERVENTIONS

Breath by breath minute volume was measured at baseline and when a dead space of 4.4 ml/kg was incorporated into the breathing circuit.

MAIN OUTCOME MEASURES

The maximum minute ventilation during tube breathing was determined and the time constant of the response calculated.

RESULTS

The time constant of the infants of smoking mothers was longer than that of the infants of non-smoking mothers (median (range) 37.3 (22.2-70.2) v 26.2 (13.8-51.0) seconds, p = 0.016). Regression analysis showed that maternal smoking status was related to the time constant independently of birth weight, gestational or postnatal age, or sex (p = 0.018).

CONCLUSIONS

Intrauterine exposure to smoking is associated with a dampened response to tube breathing.

Visually guided reaching: bilateral posterior parietal lesions cause a switch from fast visuomotor to slow cognitive control

The visually guided reaching of two patients with bilateral optic ataxia was explored in two experiments. In Experiment 1 simple delayed pointing was compared with immediate pointing. In the immediate pointing task both variable and constant errors increased with target eccentricity. In contrast to the performance of control subjects and contrary to their own beliefs, the patients both showed improved accuracy in the delay condition. This improvement was manifest as a reduction in both pointing variability and in the constant angular error towards the point of fixation. Both angular errors and their improvement with the delay were proportional to target eccentricity. Experiment 2 used a task in which the target was pre-viewed 5s prior to its re-exposure for pointing ('delayed real pointing'). On some trials a conflict was introduced between the present and previous visual information by changing the target's location during the delay. In contrast to control subjects, who ignored the pre-viewed location and aimed directly at the current target, both patients with optic ataxia initiated their movements towards the previously viewed target location. Evidently they relied on off-line information in preference to on-line visual information. In addition, the patients often failed to detect the changes in target location. One of the patients sometimes even guessed incorrectly that the target had changed its location, and her movement trajectory was then more affected by her false belief than by the target's actual location. These findings confirm that posterior parietal lesions severely disrupt direct visuomotor transformations, and suggest that the residual performance is mediated indirectly by expectations or beliefs about target position.

Synchronized mechanical ventilation for respiratory support in newborn infants

BACKGROUND

During synchronized mechanical ventilation, positive airway pressure and spontaneous inspiration coincide. Thus, if synchronous ventilation is provoked, adequate gas exchange should be achieved at lower peak airway pressures, potentially reducing barotrauma and hence airleak and chronic lung disease. Synchronous ventilation can be achieved by manipulation of rate and inspiratory time during conventional ventilation and employment of patient assisted ventilation.

OBJECTIVES

To compare (i) the efficacy of synchronized mechanical ventilation, delivered as high frequency positive pressure ventilation or triggered ventilation (patient triggered ventilation (PTV) or synchronous intermittent mandatory ventilation (SIMV)) with conventional ventilation(ii) different types of triggered ventilation

SEARCH STRATEGY

Searches from 1985-2004 of the Cochrane Central Register of Controlled Trials (CENTRAL, The Cochrane Library, Issue 3, 2004), Oxford Database of Perinatal Trials, MEDLINE, previous reviews, abstracts and symposia proceedings; hand searches of journals in the English language and contact with expert informants.

SELECTION CRITERIA

Randomized or quasi randomized clinical trials comparing synchronized ventilation delivered as high frequency positive pressure ventilation (HFPPV) or triggered ventilation (PTV/SIMV) to conventional mechanical ventilation (CMV) in neonates. Randomized trials comparing different triggered ventilation modes (PTV and SIMV) in neonates.

DATA COLLECTION AND ANALYSIS

Data regarding clinical outcomes including mortality, airleaks (pneumothorax or pulmonary interstitial emphysema (PIE)), severe intracerebral haemorrhage (grades 3 and 4), chronic lung disease (oxygen dependency beyond 28 days) and duration of weaning/ventilation. Three comparisons were made: (i) HFPPV vs CMV; (ii) PTV/SIMV vs CMV; (iii) PTV vs SIMV. Data analysis was conducted using relative risk for categorical outcomes, weighted mean difference for outcomes measured on a continuous scale.

MAIN RESULTS

Eleven studies were eligible for inclusion. The meta-analysis demonstrate that HFPPV compared to CMV was associated with a reduction in the risk of airleak (typical relative risk for pneumothorax was 0.69, 95% CI 0.51, 0.93). PTV/SIMV compared to CMV was associated with a shorter duration of ventilation (weighted mean difference -34.8 hours, 95% CI -62.1, -7.4). PTV compared to SIMV was associated with a trend to a shorter duration of weaning (weighted mean difference -42.4 hours, 95% CI -94.4, 9.6). Neither HFPPV nor triggered ventilation was associated with a significant reduction in the incidence of chronic lung disease. There was a non-significant trend towards a lower mortality rate using HFPPV versus CMV, but a non-significant trend towards a higher mortality rate using triggered ventilation versus CMV. No disadvantage of HFPPV or triggered ventilation was noted regarding other outcomes.

REVIEWERS' CONCLUSIONS

Compared to conventional ventilation, benefit is demonstrated for both HFPPV and triggered ventilation with regard to a reduction in airleak and a shorter duration of ventilation, respectively. In none of the trials was complex respiratory monitoring undertaken and thus it is not possible to conclude that the mechanism of producing those benefits is by provocation of synchronized ventilation. Further trials are needed to determine whether synchronized ventilation is associated with other benefits, but optimization of trigger and ventilator design with respect to respiratory diagnosis is encouraged before embarking on further trials.

Avoidance of obstacles in the absence of visual awareness

The spatial character of our reaching movements is extremely sensitive to potential obstacles in the workspace. We recently found that this sensitivity was retained by most patients with left visual neglect when reaching between two objects, despite the fact that they tended to ignore the leftward object when asked to bisect the space between them. This raises the possibility that obstacle avoidance does not require a conscious awareness of the obstacle avoided. We have now tested this hypothesis in a patient with visual extinction following right temporoparietal damage. Extinction is an attentional disorder in which patients fail to report stimuli on the side of space opposite a brain lesion under conditions of bilateral stimulation. Our patient avoided obstacles during reaching, to exactly the same degree, regardless of whether he was able to report their presence. This implicit processing of object location, which may depend on spared superior parietal-lobe pathways, demonstrates that conscious awareness is not necessary for normal obstacle avoidance.

Preserved obstacle avoidance during reaching in patients with left visual neglect

We asked 12 patients with left visual neglect to bisect the gap between two cylinders or to reach rapidly between them to a more distal target zone. Both tasks demanded a motor response but these responses were quite different in nature. The bisection response was a communicative act whereby the patient indicated the perceived midpoint. The reaching task carried no imperative to bisect the gap, only to maintain a safe distance from either cylinder while steering to the target zone. Optimal performance on either task could only be achieved by reference to the location of both cylinders. Our analysis focused upon the relative influence of the left and right cylinders on the lateral location of the response. In the bisection task, all neglect patients showed qualitatively the same asymmetry, with the left cylinder exerting less influence than the right. In the reaching task, the neglect group behaved like normal subjects, being influenced approximately equally by the two cylinders. This was true for all bar two of the patients, who showed clear neglect in both tasks. We conclude that the visuomotor processing underlying obstacle avoidance during reaching is preserved in most patients with left visual neglect.

Covert processing of visual form in the absence of area LO

The patient D.F., who suffers from severe visual form agnosia, has been found to have a bilateral lesion of area LO, an area known to be intimately involved in the perception of object shape. Despite her perceptual impairment, however, D.F. retains residual form processing abilities that can provide distal visuomotor control, for example in the configuration of her grasp when reaching to pick up objects of different shapes and sizes. This dissociation has been interpreted as reflecting the sparing of a dedicated system for processing the physical properties of objects solely for purposes of guiding action. Here we test this hypothesis in two studies designed to examine whether or not spared shape processing capacities might be revealed under other kinds of indirect test conditions. First, we exploited the fact that a redundant shape cue will speed search for a coloured stimulus within an array, and vice versa. Unlike our control subjects, D.F. showed no facilitation effect of either kind. Second, we used two Stroop tasks in which single coloured uppercase letters were presented. Our intention was to determine (a) whether naming the colour would be influenced by whether the letter was the initial letter of the correct or incorrect colour name (e.g. 'R' or 'G'); and (b) whether the reverse might be true, that is that D.F.'s guesses at letter identity might be influenced by their colour. We found no evidence for a Stroop effect of the former (standard) kind in D.F., but we did find evidence for reverse-Stroop effects. This result may reflect a partial sparing of ventral stream areas specialised for letter-form processing.

Delayed reaching and grasping in patients with optic ataxia

A series of experiments documenting the reaching and grasping of two patients with optic ataxia is presented. We compare their immediate responses with their behavior when required to delay for a few seconds before responding. When the delayed response is 'pantomimed', i.e. made in the absence of the target object, their performance typically improves. This pattern was predicted from a two-visual-systems model in which the cortical dorsal stream mediates normal visually guided actions while the ventral stream deals with visual information that has to be held in memory. We further found that when a 'preview' task was used in which the patients could use memorized information to guide a response to a still-present target object, they did so in preference to using the visual information facing them.

Airway resistance estimation by best fit analysis in very premature infants

Plethysmographic measurement of airway resistance (R(aw)) has been determined by single-point analysis, usually at 50% of maximum inspiratory flow (MIF). Computer-assisted (best fit) analysis, however, allows R(aw) to be calculated by applying a regression line to any portion of the plethysmograph pressure-flow loop. We determined whether the results of best fit analysis using a computer program, sampling at 200 Hz, were influenced by the portion of the inspiratory loop analysed and if best fit or single-point analysis gave more reproducible results. Twenty infants of median gestational age 26 (range 24-28) weeks, were studied at a median age of 12 (12-14) months corrected for prematurity. R(aw) was calculated by best fit analysis between 0 and 33% MIF, 0 and 50% MIF and 0 and 67% MIF and single-point analysis at 50% of MIF. Similar mean R(aw) values were obtained by best fit analysis between 0 and 33% MIF (2.79 kPa/(l/s)) and 0 and 50% MIF (3.01 kPa/(l/s)) and single-point analysis at 50% MIF (2.86 kPa/(l/s)), but best fit analysis between 0 and 67% gave higher results (3.60 kPa/(l/s)), p < 0.0001. Within the linear portion of the inspiratory loop, the mean intrasubject coefficient of variation was lowest for best fit analysis between 0 and 50% MIF. Best fit computerized analysis between 0 and 50% MIF is recommended as the analysis of choice.

Disentangling perceptual and response bias in unilateral neglect: a methodological proposal

Bisiach and his colleagues have developed a new version of Milner's "landmark task" for the purpose of separating "perceptual" and "response" biases in neglect patients. Subjects are required to decide which is the longer (or the shorter) of the two portions of a pre-bisected horizontal line. The authors proposed two indices to measure perceptual and response bias respectively. However, these indices are not mathematically independent of one another. Moreover, they do not exploit all of the information available in the data, since they do not consider the effect of the different transection locations across trials. We now propose an alternative means of analyzing data from the revised Landmark task, which generates independent estimates of perceptual and response biases. The method and its theoretical foundation are summarized, and illustrative data obtained from brain damaged patients and control subjects are presented.

Bronchodilator therapy and hyperactivity in preschool children

The common report of parents of asthmatic children that inhaled/nebulised salbutamol causes overactive behaviour was investigated. Nineteen children were assessed in a standardised setting before and after the administration of nebulised salbutamol and placebo. Neither parental report nor observer ratings suggested any significant increase in the child's level of activity.

Prehension and perception of size in left visual neglect

Right hemisphere damaged patients with and without left visual neglect, and age-matched controls had objects of various sizes presented within left or right body hemispace. Subjects were asked to estimate the objects' sizes or to reach out and grasp them, in order to assess visual size processing in perceptual-experiential and action-based contexts respectively. No impairments of size processing were detected in the prehension performance of the neglect patients but a generalised slowing of movement was observed, associated with an extended deceleration phase. Additionally both patient groups reached maximum grip aperture relatively later in the movement than did controls. For the estimation task it was predicted that the left visual neglect group would systematically underestimate the sizes of objects presented within left hemispace but no such abnormalities were observed. Possible reasons for this unexpected null finding are discussed.

Grasping the past. delay can improve visuomotor performance

"Optic ataxia" is caused by damage to the human posterior parietal cortex (PPC). It disrupts all components of a visually guided prehension movement, not only the transport of the hand toward an object's location, but also the in-flight finger movements pretailored to the metric properties of the object. Like previous cases, our patient (I.G.) was quite unable to open her handgrip appropriately when directly reaching out to pick up objects of different sizes. When first tested, she failed to do this even when she had previewed the target object 5 s earlier. Yet despite this deficit in "real" grasping, we found, counterintuitively, that I.G. showed good grip scaling when "pantomiming" a grasp for an object seen earlier but no longer present. We then found that, after practice, I.G. became able to scale her handgrip when grasping a real target object that she had previewed earlier. By interposing catch trials in which a different object was covertly substituted for the original object during the delay between preview and grasp, we found that I.G. was now using memorized visual information to calibrate her real grasping movements. These results provide new evidence that "off-line" visuomotor guidance can be provided by networks independent of the PPC.

Vertical gaze angle as a distance cue for programming reaching: insights from visual form agnosia II (of III)

It has been shown that a patient with visual form agnosia (DF) relies predominantly on vergence information when gauging target distance in an open-loop pointing task. This finding suggested that the programming of prehension might be severely disrupted if DF viewed target objects through ophthalmic prisms. An initial experiment showed that this prediction was not upheld; DF was able to programme reasonably accurate movements to objects located on a tabletop despite large changes in vergence angle. A second experiment, however, showed that placing the target objects at eye height whilst manipulating vergence angle caused gross disruption to prehension, with DF mis-programming the reach component in a predictable manner. Notably, the evidence for DF's reliance on vergence distance information was obtained in a task where the targets were viewed at eye height. These experiments indicate that DF uses vertical gaze angle to gauge target distance in normal prehension and suggest that this extra-retinal cue may be a useful source of distance information for the human nervous system, especially where pictorial cues are impoverished.

Monocular and binocular distance cues: insights from visual form agnosia I (of III)

The human nervous system constructs a Euclidean representation of near (personal) space by combining multiple sources of information (cues). We investigated the cues used for the representation of personal space in a patient with visual form agnosia (DF). Our results indicated that DF relies predominantly on binocular vergence information when determining the distance of a target despite the presence of other (retinal) cues. Notably, DF was able to construct an Euclidean representation of personal space from vergence alone. This finding supports previous assertions that vergence provides the nervous system with veridical information for the construction of personal space. The results from the current study, together with those of others, suggest that: (i) the ventral stream is responsible for extracting depth and distance information from "monocular" retinal cues (i.e. from shading, texture, perspective) and (ii) the dorsal stream has access to binocular information (from horizontal image disparities and vergence). These results also indicate that DF was not able to use size information to gauge target distance, suggesting that intact temporal cortex is necessary for "learned size" to influence distance processing. Our findings further suggest that in neurologically intact humans, object information extracted in the ventral pathway is combined with the products of dorsal stream processing for guiding prehension. Finally, we studied the "size-distance paradox" in visual form agnosia in order to explore the cognitive use of size information. The results of this experiment were consistent with a previous suggestion that the paradox is a cognitive phenomenon.

The role of size and binocular information in guiding reaching: insights from virtual reality and visual form agnosia III (of III)

Reaching out to grasp an object requires information about the size of the object and the distance between the object and the body. We used a virtual reality system with a control population and a patient with visual form agnosia (DF) in order to explore the use of binocular information and size cues in prehension. The experiments consisted of a perceptual matching task in addition to a prehension task. In the prehension task, control participants modified their reach distance in response to step changes in vergence in the absence of any clear reference for relative disparity. Their reach distance was unaffected by equivalent step changes in size, even though they used this information to modify grasp and showed a size bias in a distance matching task. Notably, DF showed the same pattern of results as the controls but was far more sensitive to step changes in vergence. This finding complements previous research suggesting that DF relies predominantly on vergence information when gauging target distance. The results from the perceptual matching tasks confirmed previous findings suggesting that DF is unable to make use of size information for perceptual matching, including distance comparisons. These data are discussed with regard to the properties of the pathways subserving the two visual cortical processing streams.

Characterisation of the Hering-Breuer deflation reflex in the human neonate

Human infants have been observed making inspiratory efforts in response to chest compression. These may be a manifestation of the Hering-Breuer deflation reflex. We sought to stimulate the reflex in 33 term infants by rapidly reducing lung volume using an inflatable jacket. The effect of altering the timing, magnitude or rate of application of the lung deflation on the strength of the inspiratory response was investigated. Inspiratory effort was quantified by measuring (1) the rate of fall in oesophageal pressure on inspiration; and (2) the mean inspiratory flow (MIF) in response to lung deflation. Variables which significantly affected (1) and resulted in increased inspiratory effort were, in order of importance: larger rises in oesophageal pressure on chest compression (38%) (percentage of variance explained), greater reductions in lung volume below functional residual capacity (FRC) (26%), faster rates of lung deflation (19%) and slower respiratory rates (11%). Increased inspiratory efforts, as assessed by response (2), were generated by greater reductions in FRC (23%), larger rises in oesophageal pressure (11%) and faster rates of lung deflation (10%). Increasing deflation pressures eventually resulted in a plateau in both measures of inspiratory response. These results were consistent with the Hering-Breuer deflation reflex being activated which could have a role in protecting the FRC of the newborn infant.

The effect of ribavirin to treat previously healthy infants admitted with acute bronchiolitis on acute and chronic respiratory morbidity

The role of ribavirin in the treatment of acute bronchiolitis is controversial. It has been suggested that the use of ribavirin may be of benefit during the acute illness and may reduce subsequent recurrent respiratory morbidity. This randomized, double-blind, placebo-controlled study was designed to determine whether ribavirin administered during the acute illness would have an influence on respiratory morbidity during both the acute illness and during the following year. Bronchial reactivity 6 months after the acute illness was also assessed. Forty previously well infants with moderately severe acute bronchiolitis were recruited during three winter epidemics. Subjects received study medication for 18 h a day. Management was otherwise unaltered. Subjects were evaluated daily by the investigator and subsequently assessed at 6 weeks, 6 months and 1 year following the acute illness. Assessment of bronchial hyper-responsiveness was assessed at 6 months of age using total body plethysmography and an established ultra-sonically nebulized distilled water challenge. A total of 40 patients (21 ribavirin, 19 placebo) were entered into the study. The two groups did not differ with respect to age, gender or clinical severity on entry to the trial. No significant differences were identified in the rate of clinical improvement over the first 24 h, the time to discharge, bronchial responsiveness at 6 months of age, frequency of significant respiratory symptoms over the first year of life and the frequency of prescribed bronchodilators and inhaled steroids during the year of follow-up. This study was unable to demonstrate any clinical benefit from the use of ribavirin in the acute illness or during subsequent follow-up for 1 year.

Volume of activation of the Hering-Breuer inflation reflex in the newborn infant

Although the Hering-Breuer inflation reflex (HBIR) is active within tidal breathing range in the neonatal period, there is no information regarding whether a critical volume has to be exceeded before any effect can be observed. To explore this, effects of multiple airway occlusions on inspiratory and expiratory timing were measured throughout tidal breathing range using a face mask and shutter system. In 20 of the 22 healthy infants studied, there was significant shortening of inspiration because the volume at which occlusion occurred rose from functional residual capacity (FRC) to end-inspiratory volume [14.9% reduction in inspiratory time (per ml/kg increase in lung volume at occlusion)]. All infants showed a significant increase in expiratory time [17.1% increase (per ml/kg increase in lung volume at occlusion)]. Polynomial regression analyses revealed a progressive increase in strength of HBIR from FRC to approximately 4 ml/kg above FRC. Eighteen infants showed no further shortening of inspiratory time and 10 infants no further lengthening of expiratory time with increasing occlusion volumes, indicating maximal stimulation of the reflex had been achieved. There was a significant relationship between strength of HBIR and respiratory rate, suggesting that HBIR modifies the breathing pattern in the neonatal period.

Visual and tactile size distortion in a patient with right neglect

One typical feature of the neglect syndrome in patients with right hemisphere damage is that they bisect horizontal lines to the right of centre. It has been argued that to a large extent these bisection errors can be attributed to a perceptual change whereby the patient experiences the left half of a line as shorter than the right half, causing them to set the midpoint of the line towards the right. We describe here a patient with a left hemisphere lesion and rightward neglect, who consequently makes bisection errors in a leftward direction. We carried out a series of tests which confirmed that he shows a subjective visual distortion in the converse direction, i.e. a perception of horizontal extents on the right as shorter than extents on the left. We also found that he shows a similar distortion in his tactile perception. The association of visual and tactile distortions in this patient is compatible with the view that the distortion effects have a rather high-level origin. Multiple single-case studies will, however, be required to establish whether this association of deficits is typical, or whether visual and tactile size distortions are separable symptoms associated with neglect.

Lateralized word recognition: assessing the role of hemispheric specialization, modes of lexical access, and perceptual asymmetry

The processing advantage for words in the right visual field (RVF) has often been assigned to parallel orthographic analysis by the left hemisphere and sequential by the right. The authors investigated this notion using the Reicher-Wheeler task to suppress influences of guesswork and an eye-tracker to ensure central fixation. RVF advantages obtained for all serial positions and identical U-shaped serial-position curves obtained for both visual fields (Experiments 1-4). These findings were not influenced by lexical constraint (Experiment 2) and were obtained with masked and nonmasked displays (Experiment 3). Moreover, words and nonwords produced similar serial-position effects in each field, but only RVF stimuli produced a word-nonword effect (Experiment 4). These findings support the notion that left-hemisphere function underlies the RVF advantage but not the notion that each hemisphere uses a different mode of orthographic analysis.

Resonance frequency in respiratory distress syndrome

AIM

To observe how the resonance frequency changes with the course of respiratory distress syndrome (RDS), by examining the effect of changing static compliance on the resonance frequency in premature infants.

METHODS

In 12 ventilated premature infants with RDS (mean gestational age 26.6 weeks, mean birth weight 0.84 kg), resonance frequency and static compliance were determined serially using phase analysis and single breath mechanics technique respectively in the first seven days of life.

RESULTS

The minimum number of measurements done in any one baby was three and maximum was five in this seven day study period. The first measurement in each baby was done within the first 72 hours of life. The increase in compliance in this period varied from 27% to 179%. The variation in the corresponding resonance frequency was within 2 Hz in eight babies and within 6 Hz in all recruited babies.

CONCLUSIONS

The resonance frequency of the respiratory system in preterm infants with RDS remains remarkably constant in the early stages of the illness, despite relatively large changes in static compliance.

Lateralized word recognition: assessing the role of hemispheric specialization, modes of lexical access, and perceptual asymmetry

The processing advantage for words in the right visual field (RVF) has often been assigned to parallel orthographic analysis by the left hemisphere and sequential by the right. The authors investigated this notion using the Reicher-Wheeler task to suppress influences of guesswork and an eye-tracker to ensure central fixation. RVF advantages obtained for all serial positions and identical U-shaped serial-position curves obtained for both visual fields (Experiments 1-4). These findings were not influenced by lexical constraint (Experiment 2) and were obtained with masked and nonmasked displays (Experiment 3). Moreover, words and nonwords produced similar serial-position effects in each field, but only RVF stimuli produced a word-nonword effect (Experiment 4). These findings support the notion that left-hemisphere function underlies the RVF advantage but not the notion that each hemisphere uses a different mode of orthographic analysis.