Phosphate adsorption by metal organic frameworks: Insights from a systematic review, meta-analysis, and predictive modelling with artificial neural networks

This comprehensive study analysed 55 articles published between 2011 and 2022 on the use of metal organic frameworks (MOFs) for phosphate adsorption. The study found that the performance of MOFs in phosphate adsorption is influenced by various factors such as the type of MOF, synthesis method, modification/alteration, and operational conditions (initial concentration, adsorbent dose, pH, contact time, and temperature). Most of the MOFs have a wide range of theoretical maximum adsorption capacity for phosphate, but their long-term use in phosphorus recovery may be limited due to the adsorption mechanisms being dominated by inner sphere complexation. The study employed machine learning to construct artificial neural network (ANN) models for predicting phosphate adsorption capacity based on input features from operation and synthesis procedures. The initial phosphate concentration was the most important input from the operational features, while the modulator agent was consistently relevant during MOF synthesis. The models showed strong fitting for most MOF types recorded for the study, such as UIO-66, MIL-100, ZIF-8, Al-MOFs, La-MOFs, and Ce-MOFs. Overall, this study provides valuable insights for the design of MOF adsorbents for phosphate adsorption and offers guidance for future research in this area.

Evaluating Osteoarthritis Management Programs: outcome domain recommendations from the OARSI Joint Effort Initiative

OBJECTIVE

To develop sets of core and optional recommended domains for describing and evaluating Osteoarthritis Management Programs (OAMPs), with a focus on hip and knee Osteoarthritis (OA).

DESIGN

We conducted a 3-round modified Delphi survey involving an international group of researchers, health professionals, health administrators and people with OA. In Round 1, participants ranked the importance of 75 outcome and descriptive domains in five categories: patient impacts, implementation outcomes, and characteristics of the OAMP and its participants and clinicians. Domains ranked as "important" or "essential" by ≥80% of participants were retained, and participants could suggest additional domains. In Round 2, participants rated their level of agreement that each domain was essential for evaluating OAMPs: 0 = strongly disagree to 10 = strongly agree. A domain was retained if ≥80% rated it ≥6. In Round 3, participants rated remaining domains using same scale as in Round 2; a domain was recommended as "core" if ≥80% of participants rated it ≥9 and as "optional" if ≥80% rated it ≥7.

RESULTS

A total of 178 individuals from 26 countries participated; 85 completed all survey rounds. Only one domain, "ability to participate in daily activities", met criteria for a core domain; 25 domains met criteria for an optional recommendation: 8 Patient Impacts, 5 Implementation Outcomes, 5 Participant Characteristics, 3 OAMP Characteristics and 4 Clinician Characteristics.

CONCLUSION

The ability of patients with OA to participate in daily activities should be evaluated in all OAMPs. Teams evaluating OAMPs should consider including domains from the optional recommended set, with representation from all five categories and based on stakeholder priorities in their local context.

Abstract P1-01-11: Nuclear immunohistochemical IKK-ϵexpression in flat epithelial atypia (FEA) of the breast: A predictor of ipsilateral ADH, in-situ or invasive malignancy?

Background:Flat Epithelial Atypia of the breast (FEA) is associated with in situ and invasive low grade neoplasia. However, the role of excision after FEA on biopsy is controversial as rates of upgrading to atypical ductal hyperplasia (ADH), ductal carcinoma in situ (DCIS) or invasive carcinoma in subsequent excision are relatively low. Problems include difficulties in inter-observer reproducibility and lack of morphologic or immunohistochemistry (IHC) tools that better identify cases at risk for concurrent ADH/Carcinoma. Nuclear image analysis may be useful, but is not widely available. IKK-ϵ, part of the NF-kB activating pathway, is absent in normal breast epithelium and non atypical (usual) ductal hyperplasia, but is over-expressed in >30% of breast cancers. In addition, in our experience ADH/DCIS shows IKK-ϵ staining, mostly cytoplasmic. Of note, in prostate cancer, nuclear accumulation of IKK-ϵ has been described in hormone sensitive prostate disease while cytoplasmic accumulation is associated with metastatic progression. No previous studies of IKK-ϵ levels in FEA are reported. Here we report IKK-ϵ status in FEA and correlation with ipsilateral, synchronous ADH, DCIS or invasive carcinoma.

Method: Resection specimens from 61 patients with diagnosis of FEA were retrieved. Presence of ADH/carcinoma and laterality (ipsi or contralateral) was recorded. Synchronous neoplasia was defined as ADH, DCIS or invasive carcinoma diagnosed within 6 months of the diagnosis of FEA. Presence of FEA was confirmed by three observers using strict morphologic criteria. IHC for IKK-ϵ was performed using ABCAM, rabbit anti-IKK-ϵ (ab7891) and pH 6 citrate buffer heat-induced epitope retrieval for 20 minutes. IHC slides were scanned and FEA regions captured for blind scoring of nuclear and cytoplasmic staining. Cut off for positive nuclear staining was 10% and cytoplasmic staining was graded as negative, weak, moderate or strong positive.

Results:40 patients had ipsilateral synchronous ADH/carcinoma, and 21 did not. Within these groups, 6 patients had contralateral ADH/carcinoma (2 with and 4 without ipsilateral neoplasia). While cytoplasmic staining showed no difference between the groups, nuclear positivity was more frequent in cases with ipsilateral synchronous ADH/carcinoma, χ2(1, N = 61) = 5.1, p = .025 (Table 1). In contrast, there was no correlation between IKK-ϵ staining and ADH/carcinoma in the opposite breast (p=.25).

Table 1Nuclear IKK-eSynchronous Ipsilateral ADH/DCIS/Carcinoma Negative (%)Positive (%)TotalNegative10 (48)11 (52)21Positive10 (25)30 (75)40

Conclusion:Nuclear IKK-ϵ staining may prove useful in predicting synchronous ipsilateral ADH or malignancy in cases of FEA in biopsy material. Given its more frequent association with ipsilateral synchronous ADH/carcinoma, IKK-ϵ nuclear expression in FEA may represent a step in continuous local oncogenesis rather than a general marker of risk. Given the pleiotropic role of IKK-ϵ in growth and survival, the significance of the shift from nuclear staining in FEA to cytoplasmic staining in ADH/DCIS may reflect different signaling pathways and requires further investigation. Further validation of our findings in larger cohorts is necessary.

Citation Format: Williams PA, Parra-Herran CE, Ayroud Y, Islam S, Gravel DH, Robertson SJ, Pratt C. Nuclear immunohistochemical IKK-ϵexpression in flat epithelial atypia (FEA) of the breast: A predictor of ipsilateral ADH, in-situ or invasive malignancy?. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P1-01-11.

Enhanced biogas production using cow manure to stabilize co-digestion of whey and primary sludge

Increasing biogas production from municipal anaerobic digesters via additional loading with industrial/agricultural wastes offers a low-cost, sustainable energy generation option of significant untapped potential. In this work, bench-top reactors were used to mimic a full-scale primary sludge digester operating at an organic loading rate (OLR) of 2.4 kg COD/m3 d and a 20 d hydraulic retention time (HRT). Co-digestion of whey with primary sludge was sustained at a loading rate of 3.2 kg COD/m3 d (17 d HRT) and boosted gas production to 151% compared to primary sludge digestion alone. Addition of chemical alkalinity enabled co-digestion of whey with primary sludge to be maintained at an elevated OLR of 6.4 kg COD/m3 d (11 d HRT) with gas production increased to 208%. However, when the chemical addition was simply replaced by cow manure, stable operation was maintained at OLRs of 5.2-6.9 kg COD/m3 d (11-14 d HRT) with gas production boosted up to 268%.

Effect of whey storage on biogas produced by co-digestion of sewage sludge and whey

Biogas production from municipal anaerobic digesters could potentially be boosted via co-digestion with organic wastes such as whey. The challenge is that whey production is seasonal. This research examined the effect of storing whey at ambient temperature on: (1) whey composition; (2) biogas production from co-digestion of the stored whey with municipal primary sludge. Whey storage resulted in acidification with formation of acetate, propionate and butyrate and a 9% reduction in total chemical oxygen demand (COD) over the 9-month trial. A control digester fed with primary sludge produced 0.18-0.23 m3 CH4/kgCOD(added). Co-digestion of fresh whey and sludge increased biogas production and the methane contribution from the whey was 0.29 m3CH4/kgCOD(added). When the fresh whey was substituted with stored whey, methane production by the whey remained at 0.29 m3CH4/kgCOD(added). The ability to store whey at ambient temperature and allow co-digestion year round will significantly improve the economics of biogas production from whey.

Abstract PD09-01: BRCA1 inactivation induces NF-κB in human breast cancer cells and in murine and human mammary glands

Understanding the biological mechanisms underlying the initiation and progression of breast cancer it is an important step for its prevention and treatment. In 2011 in the United States, approximately 230,000 women were diagnosed with breast cancer and 40,000 died. Individuals with mutations in breast cancer-associated gene 1 (BRCA1) have a lifetime risk of developing breast cancer up to 85%.

It is well known that BRCA1 participates in DNA damage repair and cell cycle checkpoint control, serving as a tumor suppressor gene to maintain the global genomic stability. However, BRCA1 has also been shown to play a key role in maturation of mammary stem/progenitor cells, which are the targets for carcinogenesis in individuals who have undergone loss of heterozygosity (LOH) for BRCA1. Recently, it has also been shown that NF-κB activity is increased in both mammary carcinoma cell lines and primary human breast cancer tissue. Indeed, in a previous study it has been demonstrated that NF-κB inducible kinase (NIK), p100/p52 and RelB (all components of the alternative NF-κB pathways) were increased in BRCA1-mutated tumors.

Here we show that BRCA1-loss or -mutation is responsible for activation of the alternative NF-κB pathway evidenced by NIK and IκB kinase-α (IKKα) phosphorylation, processing of p100 to p52 and p52/RelB nuclear localization. Moreover, increased p52 was also observed after BRCA1 inhibition. A BRCA1-mutated human breast cancer cell line (HCC1937) was also used to understand the role played by NIK in NF-κB alternative pathway activation. Indeed, NIK inhibition in HCC1937 cell line resulted in a decrease in p52 formation. Moreover, a decrease in NIK mRNA level was also observed when wild-type BRCA1 was reconstituted in HCC1937 cells. BRCA1 inactivation in MCF-7 cells also induced NIK phosphorylation and nuclear localization of RelB and p52. Overall, these data show that inactivation of BRCA1 increases NIK mRNA level, associated with induction of the NF-κB alternative pathway.

Stem/progenitors cells sorted using the CD24/CD49f immunophenotype derived from BRCA1 knockout mouse mammary glands showed alternative NF-κB pathway activation. Inhibition of IKKα/β using BMS-345541 completely blocked mammary colony formation in a Matrigel assay. Moreover, increased p52 formation was found in mammary stem/progenitor cells and mammary gland paraffin sections obtained from BRCA1 knockout mice. Remarkably, RelB and p100/p52 were highly expressed in 20–50% of the lobular structures in histologically normal breast tissue obtained from human BRCA1 mutation carriers while no staining was evident in normal tissue from non-carrier mastectomy samples.

Our data show that BRCA1 inactivation induces alternative NF-κB activation which ultimately promotes the expansion of the mammary progenitor population. These novel findings provide a new basis for functional classification of BRCA1 mutations and a potential method for predicting breast cancer in BRCA1 mutation carriers. Lastly our results suggest that targeting the alternative NF-κB pathway could be of benefit in the prevention of BRCA1-associated breast cancer by limiting progenitor cell expansion.

Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr PD09-01.

Chemical techniques for pretreating and regenerating active slag filters for improved phosphorus removal

Active slag filters are an emerging technology for removing phosphorus (P) from wastewaters. Recent research revealed that adsorption onto Fe oxides/oxyhydroxides at near-neutral pH and oxidizing Eh is the key mechanism of P removal by melter slag filters. Currently, filter lifespan is limited by available adsorption sites. This study examined whether the performance and longevity of active filters could be improved via chemical treatment to create additional reactive sites as well as regenerate exhausted ones. Fresh original melter slag as well as slag from an exhausted full-scale filter was tested. Chemical reagents that could manipulate the pH/Eh of the slag granule surfaces and potentially activate them for further P removal were used, namely hydrochloric acid (HCI), sodium hydroxide (NaOH) and sodium dithionite (Na2S2O4). Waste stabilization pond effluent was then applied to the treated slag to assess the effectiveness of the treatments at improving P removal. Fresh slag treated with Na2S204 and HCl, respectively, retained 1.9 and 1.4 times more P from the effluent than the untreated fresh slag. These reagents were even more effective at regenerating the exhausted slag, increasing total retained P by a factor of 13 and six, respectively, compared with untreated slag. Sodium hydroxide was ineffective at increasing P removal. The higher P retention by the 'treated exhausted slag' compared with the 'treated fresh media' indicates that adsorption sites on melter slag filters become increasingly reactive with time. This research is the first study to provide evidence that P retention by active slag filters can be increased by both (1) chemical pre treatment and (2) chemical post-treatment once their P removal is exhausted, thereby potentially transforming them from a single use system to a more viable, reusable treatment technology.

Active slag filters-simple and sustainable phosphorus removal from wastewater using steel industry byproduct

Active filtration, where effluent is passed through a reactive substrate such as steel slag, offers a simple and cost-effective option for removing phosphorus (P) from effluent. This work summarises a series of studies that focused on the world's only full-scale active slag filter operated through to exhaustion. The filter achieved 75% P-removal during its first 5 years, reaching a retention capacity of 1.23 g P/kg slag but then its performance sharply declined. Scanning electron microscopy, X-ray diffraction, X-ray fluorescence, and chemical extractions revealed that P sequestration was primarily achieved via adsorption onto iron (Fe) oxyhydroxides on the slag's surface. It was concluded that batch equilibrium tests, whose use has been repeatedly proposed in the literature, cannot be used as an accurate predictor of filter adsorption capacity because Fe oxyhydroxides form via chemical weathering in the field, and laboratory tests don't account for this. Research into how chemical conditions affect slag's P retention capacity demonstrated that near-neutral pH and high redox are optimal for Fe oxyhydroxide stability and overall filter performance. However, as Fe oxyhydroxide sites fill up, removal capacity becomes exhausted. Attempts to regenerate P removal efficiency using physical techniques proved ineffective contrary to dogma in the literature. Based on the newly-developed understanding of the mechanisms of P removal, chemical regeneration techniques were investigated and were shown to strip large quantities of P from filter adsorption sites leading to a regenerated P removal efficiency. This raises the prospect of developing a breakthrough technology that can repeatedly remove and recover P from effluent.

Suitability of adsorption isotherms for predicting the retention capacity of active slag filters removing phosphorus from wastewater

Active slag filters are an emerging technology for removing phosphorus (P) from wastewater. A number of researchers have suggested that adsorption isotherms are a useful tool for predicting P retention capacity. However, to date the appropriateness of using isotherms for slag filter design remains unverified due to the absence of benchmark data from a full-scale, field filter operated to exhaustion. This investigation compared the isotherm-predicted P retention capacity of a melter slag with the P adsorption capacity determined from a full-scale, melter slag filter which had reached exhaustion after five years of successfully removing P from waste stabilization pond effluent. Results from the standard laboratory batch test showed that P adsorption correlated more strongly with the Freundlich Isotherm (R(2)=0.97, P<0.01) than the Langmuir Isotherm, a similar finding to previous studies. However, at a P concentration of 10 mg/L, typical of domestic effluent, the Freundlich equation predicted a retention capacity of 0.014 gP/kg slag; markedly lower than the 1.23 gP/kg slag adsorbed by the field filter. Clearly, the result generated by the isotherm bears no resemblance to actual field capacity. Scanning electron microscopy analysis revealed porous, reactive secondary minerals on the slag granule surfaces from the field filter which were likely created by weathering. This slow weathering effect, which generates substantial new adsorption sites, is not accounted for by adsorption isotherms rendering them ineffective in slag filter design.

Process evaluation results from a school- and community-linked intervention: the Trial of Activity for Adolescent Girls (TAAG)

Process evaluation is a component of intervention research that evaluates whether interventions are delivered and received as intended. Here, we describe the process evaluation results for the Trial of Activity for Adolescent Girls (TAAG) intervention. The intervention consisted of four synergistic components designed to provide supportive school- and community-linked environments to prevent the decline in physical activity in adolescent girls. Process evaluation results indicate that the intervention components were delivered from intervention staff to teachers with high fidelity (84-97%) to the protocol and with lower fidelity (range: 18-93%) from teachers to students. Physical activity programs for girls, a unique feature of the TAAG intervention, increased from a mean of 10 programs per school to a mean of 16 and 15 in years 1 and 2, respectively, in intervention schools, with no change in control schools. These findings suggest that a multicomponent school- and community-based physical activity intervention can be delivered with fidelity and result in a middle school environment that supports physical activity for girls.

Effects of redox potential and pH changes on phosphorus retention by melter slag filters treating wastewater

The release of phosphorus (P) and iron (Fe) from a melter slag filter in solutions of varying Eh and pH was examined. The filter had been removing P from waste stabilization pond effluent for several years. The study revealed that the highest P (95% of total P) and Fe (25% of total Fe) release from the slag occurred in the solution with the lowest Eh (-400 mV, relative to the standard hydrogen electrode, SHE) and lowest pH (4.9). Solutions with high pH (9.1) also proved favorable for P release (20 to 40% of total P) from the slag, at both reducing (-400 mV) and oxidizing (+300 mV) Eh. By contrast, solutions with pH 4.9 and 6.7 and oxidizing Eh (+300 mV) liberated the lowest P and Fe contents into the aqueous phase (<1% for both elements). The findings showed that Eh and pH are important parameters affecting P release from slag filters. At low Eh and low pH, P is released due to the dissolution of Fe oxides/oxyhydroxides, as supported by scanning electron microscopy (SEM)/energy dispersive spectrometry (EDS). At high pH, P is desorbed from negatively charged Fe oxide/oxyhydroxide surfaces. The results of this investigation are pertinentto the design and operation of melter slag filters that treat all forms of P-rich waters, such as wastewater, stormwater, and farm runoff. The study demonstrated that P retention by melter slag filters is optimal in water bodies characterized by near-neutral pH and oxidizing Eh because these conditions favor P adsorption onto Fe oxides/oxyhydroxides.

Trismus: An unconventional approach to treatment

A 63 year-old man who had had an operation for adenocarcinoma of the left parotid gland presented with worsening trismus after the completion of radiotherapy. None of the treatments given were successful so he resorted to a "home-made" approach, and succeeded in improving his mouth-opening by 18 mm.

Effect of fragile X status categories and FMRP deficits on cognitive profiles estimated by robust pedigree analysis

The effect of the fragile X pre-mutation and full mutation categories, and FMRP deficits in these categories, on neurocognitive status, have been assessed in fragile X individuals from 144 extended families, which included fragile X individuals, as well as their non-fragile X relatives. Neuropsychological status was assessed by the Wechsler summary and subtest test scores. A modification of the maximum likelihood estimators for pedigree data that is resistant to outliers was used to analyze the data. The results have demonstrated the effect of large expansions of CGG repeat in the FMR1 (fragile X mental retardation 1) gene (full mutation) in decreasing full scale IQ (FSIQ), as well as several FSIQ-adjusted subtest scores in the performance domain. Moreover, the results have demonstrated significant cognitive deficits in male individuals with pre-mutation. FMRP depletion correlates strongly with neurocognitive status in the full mutation subjects. Evidence for the effect of FMRP in smaller expansions (pre-mutation) in reducing FSIQ, Performance and Verbal scores, as well as subtest scores in males, has also been obtained. The results are also suggestive of factors other than FMRP deficit which may determine some specific cognitive deficits in fragile X pre-mutation carriers. Genetic variance estimated from the models accounts for less than half of the total variance in FSIQ, and it varies widely between individual Wechsler subtests.

Parotid neoplasms in children: experience of diagnosis and management in a district general hospital

Parotid neoplasms are uncommon in children and the available literature is predominantly from specialized centres. This paper highlights our experience at a district general hospital, in the diagnosis and management of parotid neoplasms in children. The case records of all parotidectomies performed in a 26-year period between 1974-1999 were scrutinized and patients aged 18 years and below identified. The demographic data, histology, presentation, investigations, treatment, outcomes and complications were analysed. 545 parotidectomies were performed in 536 patients, in whom 569 neoplasms were diagnosed. Only 12 patients aged 18 and under were identified (2.2%). The relative frequency of individual tumours differed markedly from that in adults. 75% of the tumours were benign. Pleomorphic adenoma and mucoepidermoid carcinoma were the most common tumours. A painless mass was the most frequent clinical presentation and CT sialogram was the most common investigation. Parotidectomy with preservation of the facial nerve was performed in all cases, and adjuvant radiotherapy employed in the case of malignant tumours. All patients were alive and well at the time of last follow up. Transient facial nerve palsy and hypertrophic scars were the most common complications.

Relations between the development of patterns of sleeping heart rate and body temperature in infants

Overnight patterns of rectal temperature and heart rate were recorded from 119 normal infants at weekly intervals from 7 to about 16 weeks of age. All data were collected in the infants' own homes. As previously reported, different infants developed an adult-like night time rectal temperature pattern abruptly at different ages. When heart rate data were collated by age, there was an apparently gradual fall in sleeping heart rate from 7 to about 14 weeks of age. This was, however, an artefact of data collation. Individual infants showed abrupt falls in heart rate at the time that the adult-like body temperature pattern appeared, but this occurred at different ages in different babies, so when data were collated cross sectionally, an apparently gradual fall resulted. The relation between the developmental changes in sleeping heart rate and rectal temperature was different in boys and girls, with girls showing a more abrupt and greater change in heart rate at the time of development of the adult-like body temperature pattern. Infants whose parents smoked had significantly lower heart rates once the adult-like body temperature pattern had appeared.

A pilot safety trial of prolonged (48 h) infusion of the dual endothelin-receptor antagonist tezosentan in patients with advanced heart failure

STUDY OBJECTIVES

Tezosentan, an IV dual endothelin-receptor antagonist, has demonstrated beneficial hemodynamic effects in patients with advanced heart failure. In addition, no notable differences in safety and tolerability variables were detected between tezosentan-treated and placebo-treated patients when infused over 4 to 6 h. The present study was conducted primarily to assess the safety and tolerability of tezosentan when administered over a prolonged, 48-h treatment period, and secondarily to investigate hemodynamic response.

DESIGN

This randomized, double-blind, active-controlled study of continual IV administration of two dosages of tezosentan (20 mg/h and 50 mg/h; n = 6 each) or dobutamine (5 microg/kg/min; n = 2) over 48 h in patients with advanced heart failure was conducted to assess tolerability, safety, and hemodynamic variables (Doppler echocardiography).

RESULTS

During tezosentan infusion, no episodes of hypotension requiring withdrawal of therapy occurred, and hemodynamic rebound was not observed after abrupt cessation of the infusion. There were no reports of worsening heart failure in tezosentan-treated patients up to 28 days following the infusion. The most common side effect during the infusion was headache (9 of 12 tezosentan-treated patients and both dobutamine-treated patients). Echocardiographic Doppler measurements suggested improvements in cardiac index, pulmonary capillary wedge pressure, and relaxation properties as well as in diastolic and systolic function in all treatment groups.

CONCLUSIONS

Prolonged, 48-h IV dual endothelin-receptor antagonism with tezosentan was well tolerated with no new safety concerns emerging. These data further support the potential role of tezosentan in the treatment of patients with acute heart failure.

The effect of oral vocabulary on reading visually novel words: a comparison of the dual-route-cascaded and triangle frameworks

Dual-route-cascaded (DRC) (e.g. Coltheart & Rastle, Journal of Experimental Psychology: Human Perception and Performance 20 (1994) 1197) and triangle framework (e.g. Seidenberg & McClelland, Psychological Review 96 (1989) 523) predictions were tested regarding the effect of having a word in oral vocabulary prior to reading that same word. Over two sessions, at intervals of 2--3 days, 44 Grade 1 (6--7-year-old) children were aurally familiarized with the sound and meaning of ten novel words (semantic oral instantiation), and with just the sound of another ten novel words (non-semantic oral instantiation). Two to three days later non-word naming performance was significantly more accurate for aurally trained novel words compared to pseudohomophones, which were in turn advantaged over untrained non-words. The semantic manipulation had no effect. Experiment 2 manipulated articulation during (non-semantic) training. Forty Grade 1 children participated. Again, aurally trained items were named more accurately and quickly than equivalently trained pseudohomophones, which were in turn advantaged over untrained non-words. The articulation manipulation had no effect. The results suggest that word-specific phonological information is represented in the reading system independently of semantic or articulatory influences. The results are interpreted as being problematic for both the DRC and triangle frameworks, but more so for the latter.

A phase I study of irinotecan in pediatric patients: a pediatric oncology group study

A Phase I trial of irinotecan was performed to determine the maximum tolerated dose (MTD), the dose-limiting toxicities (DLTs), and the incidence and severity of other toxicities in children with refractory solid tumors. Thirty-five children received 146 courses of irinotecan administered as a 60-min i.v. infusion, daily for 5 days, every 21 days, after premedication with dexamethasone and ondansetron. Doses ranged from 30 mg/m2 to 65 mg/m2. An MTD was defined in heavily pretreated and less-heavily pretreated (i.e., two prior chemotherapy regimens, no prior bone marrow transplantation, and no radiation to the spine, skull, ribs, or pelvic bones) patients. Myelosuppression was the primary DLT in heavily pretreated patients, and diarrhea was the DLT in less-heavily pretreated patients. The MTD in the heavily pretreated patient group was 39 mg/m2, and the MTD in the less-heavily pretreated patients was 50 mg/m2. Non-dose-limiting diarrhea that was well controlled and of brief duration was observed in approximately 75% of patients. A partial response was observed in one patient with neuroblastoma, and in one patient with hepatocellular carcinoma. Stable disease (4-20 cycles) was observed in seven patients with a variety of malignancies including neuroblastoma, pineoblastoma, glioblastoma, brainstem glioma, osteosarcoma, hepatoblastoma, and a central nervous system rhabdoid tumor. In conclusion, the recommended Phase II dose of irinotecan administered as a 60-min i.v. infusion daily for 5 days, every 21 days, is 39 mg/m2 in heavily treated and 50 mg/m2 in less-heavily treated children with solid tumors.

The use of orthographic and phonological strategies for the decoding of words in children with developmental dyslexia and average readers

Children with developmental dyslexia are known to have problems with phonological awareness and, in particular, with phonological decoding. This study was aimed at determining the relationship between orthographic and phonological decoding strategies used by a group of children with developmental dyslexia and two groups of children who were average readers (matched on reading age and chronological age, respectively). The three groups of children, 12 in each, were presented with single words, either visually or orally. The children were asked to pronounce these words using either an orthographic (spelling) strategy following mental deletion of one letter, or a phonological (sounding) strategy following mental deletion of one sound. Analysis of variance (ANOVA) revealed that the reading age control group were more accurate when using phonological strategies than when using orthographic strategies, whereas the chronological age control group generally showed superior orthographic and phonological processing abilities compared with both the developmental dyslexia and reading age control groups. Compared with both chronological and reading age control groups, children in the developmental dyslexia group had more difficulty when using a phonological strategy, particularly when words were presented auditorily. However, compared with their performance on phonological tasks, the developmental dyslexia group performed at a level commensurate with their age when carrying out the orthographic tasks.

'Now please wash your hands': the handwashing behaviour of final MBBS candidates

The Handwashing Liaison Group has pointed out that "The failure of healthcare workers to decontaminate their hands reflects fundamentals of attitudes, beliefs and behaviours". Doctors are known to be poor at handwashing. This poor compliance may have its roots in a failure to learn this behaviour at medical college, where the influence of consultants and other role models may be critical. The handwashing behaviour of modern day medical students has not been previously studied. The Final MBBS Objective Structured Clinical Examination (OSCE) reflects learnt behaviours and attitudes of final year medical students 'absorbed' from role models within their training. We observed the handwashing behaviour of 187 candidates during the 1998 Final MBBS OSCE, at one clinical station, neurological examination of the lower limbs. Only 8.5% of candidates washed their hands after patient contact, although this figure rose to 18.3% with the aid of handwashing signs. These findings suggest that handwashing should become an educational priority. As student learning is highly focused by assessment (in-course or examination), we sug-gest that compliance with handwashing be built into undergraduate and Teaching Quality assessments with, for example, 'Hygiene marks' incorporated into OSCE or observed long case checklists. This study re-emphasizes the need for good clinical practice whenever teaching medical students.

An evaluation of the impact of a self-care coping intervention on psychological and clinical outcomes in adolescents with newly diagnosed cancer

The demands of cancer treatment are particularly challenging for newly diagnosed adolescents. If attempts to cope with these demands are unsuccessful, adolescents may not comply with or may refuse treatment. As a result, their chances of survival are decreased. The purpose of this study, guided by the Adolescent Self-Sustaining Model, was to determine the effects of a three-part educational intervention designed to facilitate copying on psychological (hopefulness, hopelessness, self-esteem, self-efficacy and symptom distress) and clinical outcomes (treatment toxicity) among adolescents newly diagnosed with cancer. This two-site study used a longitudinal experimental two-group design with adolescents randomly assigned to the intervention or control group. Four measurement points spanning the first 6 months of treatment were included in the design. Of 93 eligible adolescents, 78 (46 females and 32 males) agreed to participate. No statistically significant differences between the intervention and control groups, or between male and female participants, were detected at any measurement point. Differences in scores over time within groups were noted. Explanations for the lack of group differences are offered, as are recommendations for strengthening the intervention and design for future testing.

Characteristics of preschool and school-age children with imaginary companions

The authors investigated the prevalence and characteristics of children who experience or who have experienced imaginary companions. For the study, a self-administered questionnaire that sought information regarding the characteristics of children with and without imaginary companions was completed by 478 parents of children within the age range of 3 to 9.5 years. A significantly larger number of children with imaginary companions were reported to be first-born children, to be very imaginative, to incorporate myth in their play, and to explain events as magical. Overall, these results are interpreted to indicate that birth order, combined with characteristics such as imaginativeness and a predisposition to engage in fantasy, characterizes children with imaginary companions.

Cardiovascular safety of fexofenadine HCl

BACKGROUND

Certain first- and second-generation H1-receptor antagonists are associated with prolongation of the corrected QT interval (QTc) and, in rare instances, with ventricular dysrhythmias, including torsades de pointes ventricular tachycardia.

OBJECTIVE

To assess the effect of fexofenadine HCl, a new non-sedating antihistamine, on QTc.

METHODS

Dose-tolerance, safety, and drug-interaction studies with healthy volunteers; and clinical efficacy studies with seasonal allergic rhinitis patients were conducted. Twelve-lead ECG data were collected pre- and postdosing or serially throughout these studies. Outliers were defined as QTc >440 msec with a >/=10 msec increase from baseline.

RESULTS

Fexofenadine HCl at single doses up to 800 mg q.d. (once daily) and multiple doses up to 690 mg b.d. for 28 days in healthy volunteers resulted in no increases in QTc (recommended dose range is 120-180 mg daily); QTc changes were similar to placebo. Compared with placebo, there were no statistically significant QTc increases in patients receiving fexofenadine HCl 80 mg b.d. for 3 months, 60 mg b. d. for 6 months, or 240 mg q.d. for 12 months. No statistically significant increases in QTc were detected when fexofenadine HCl 120 mg b.d. was administered in combination with erythromycin (500 mg t. d.) or ketoconazole (400 mg q.d.) after dosing to steady-state (6.5 days). In seasonal allergic rhinitis patients (n = 1160) treated with 40, 60, 120, or 240 mg b.d. fexofenadine HCl for 2 weeks, there were no dose-related increases in QTc and no significant increases in mean QTc compared with placebo. Frequency and magnitude of QTc outliers with fexofenadine HCl and placebo were similar in all studies. No case of fexofenadine-associated torsades de pointes has been observed in controlled trial experience with more than 6000 patients.

CONCLUSION

Fexofenadine HCl has been investigated more extensively for possible electrophysiological effects than any other antihistamine. Fexofenadine HCl has no significant effect on QTc, even at doses much higher than those used in clinical practice.