Peri-operative delineation of non-melanoma skin cancer margins in vivo with handheld reflectance confocal microscopy and video-mosaicking

BACKGROUND

The surgical removal of non-melanoma skin cancers (NMSCs) is guided by the pathologic examination of margins. However, the preparation of histopathology is time consuming, labour-intensive and requires separate laboratory infrastructure. Furthermore, when histopathology indicates positive margins, patients must return for re-excisions. Reflectance confocal microscopy (RCM) with a new video-mosaicking approach can noninvasively delineate margins directly on patients and potentially guide surgery in real-time, augmenting the traditional approaches of histopathology.

OBJECTIVE

To assess a new peri-operative RCM video-mosaicking approach for comprehensive delineation of NMSC margins on patients in vivo.

METHODS

Thirty-five patients undergoing Mohs micrographic surgery (MMS) in the Mohs surgery unit at Memorial Sloan Kettering Cancer Center, New York, NY were included in the study. RCM imaging was performed before and after the first staged excision by acquiring videos along the surgical margins (epidermal, peripheral and deep dermal) of each wound, which were subsequently processed into video-mosaics. Two RCM evaluators read and assessed video-mosaics, and subsequently compared to the corresponding Mohs frozen histopathology.

RESULTS

Reflectance confocal microscopy videos and video-mosaics displayed acceptable imaging quality (resolution and contrast), pre-operatively in 32/35 (91%) NMSC lesions and intra-operatively in 29/35 lesions (83%). Pre-operative delineation of margins correlated with the histopathology in 32/35 (91%) lesions. Intra-operative delineation correlated in 10/14 (71%) lesions for the presence of residual tumour and in 18/21 (86%) lesions for absence. Sensitivity/specificity were 71%/86% and 86%/81% for two RCM video-mosaic evaluators, and overall agreement was 80% and 83% with histopathology, with moderate inter-evaluator agreement (k = 0.59, P ≤ 0.0002).

CONCLUSIONS

Peri-operative RCM video-mosaicking of NMSC margins directly on patients may potentially guide surgery in real-time, serve as an adjunct to histopathology, reduce time spent in clinic and reduce the need for re-excisions. Further testing in larger studies is needed.

Prognostic value of tumour regression grade in locally advanced rectal cancer: a systematic review and meta-analysis

AIM

The current standard of care for locally advanced rectal cancer involves neoadjuvant chemoradiotherapy (CRT) followed by total mesorectal excision. There is a spectrum of response to neoadjuvant therapy; however, the prognostic value of tumour regression grade (TRG) in predicting disease-free survival (DFS) or overall survival (OS) is inconsistent in the literature.

METHOD

This study was performed in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. A systematic search was undertaken using Ovid MEDLINE, Embase and Google Scholar. Inclusion criteria were Stage II and III locally advanced rectal cancer treated with long-course CRT followed by radical surgery. The aim of the meta-analysis was to assess the prognostic implication of each TRG for rectal cancer following neoadjuvant CRT. Long-term prognosis was assessed. The main outcome measures were DFS and OS. A random effects model was performed to pool the hazard ratio (HR) from all included studies.

RESULTS

There were 4875 patients from 17 studies, with 775 (15.9%) attaining a pathological complete response (pCR) and 719 (29.9%) with no response. A significant association with OS was identified from a pooled-estimated HR for pCR (HR = 0.47, P = 0.002) and nonresponding tumours (HR = 2.97; P < 0.001). Previously known tumour characteristics, such as ypN, lymphovascular invasion and perineural invasion, were also significantly associated with DFS and OS, with estimated pooled HRs of 2.2, 1.4 and 2.3, respectively.

CONCLUSION

In conclusion, the degree of TRG was of prognostic value in predicting long-term outcomes. The current challenge is the development of a high-validity tests to predict pCR.

Impaired awareness of motor intention in functional neurological disorder: implications for voluntary and functional movement

BACKGROUND

Functional neurological disorders (FNDs), also known as conversion disorder, are unexplained neurological symptoms unrelated to a neurological cause. The disorder is common, yet poorly understood. The symptoms are experienced as involuntary but have similarities to voluntary processes. Here we studied intention awareness in FND.

METHOD

A total of 26 FND patients and 25 healthy volunteers participated in this functional magnetic resonance study using Libet's clock.

RESULTS

FND is characterized by delayed awareness of the intention to move relative to the movement itself. The reporting of intention was more precise, suggesting that these findings are reliable and unrelated to non-specific attentional deficits. That these findings were more prominent with aberrant positive functional movement symptoms rather than negative symptoms may be relevant to impairments in timing for an inhibitory veto process. Attention towards intention relative to movement was associated with lower right inferior parietal cortex activity in FND, a region early in the processing of intention. During rest, aberrant functional connectivity was observed with the right inferior parietal cortex and other motor intention regions.

CONCLUSIONS

The results converge with observations of low inferior parietal activity comparing involuntary with voluntary movement in FND, emphasizing core deficiencies in intention. Heightened precision of this impaired intention is consistent with Bayesian theories of impaired top-down priors that might influence the sense of involuntariness. A primary impairment in voluntary motor intention at an early processing stage might explain clinical observations of slowed effortful voluntary movement, heightened self-directed attention and underlie functional movements. These findings further suggest novel therapeutic targets.

Systematic review of the influence of chemotherapy-associated liver injury on outcome after partial hepatectomy for colorectal liver metastases

BACKGROUND

The impact of chemotherapy-associated liver injury (CALI) on postoperative outcome in patients undergoing partial hepatectomy for colorectal liver metastases (CRLM) remains controversial. The objective of this study was to clarify the effect of CALI (sinusoidal dilatation (SD), steatosis and steatohepatitis) on postoperative morbidity and mortality by investigating a large data set from multiple international centres.

METHODS

PubMed and Embase were searched for studies published between 1 January 2004 and 31 December 2013 with keywords 'chemotherapy', 'liver resection', 'outcome' and 'colorectal metastases' to identify potential collaborating centres. Univariable and multivariable analyses were performed using binary logistic regression models, with results presented as odds ratios (ORs) with 95 per cent confidence intervals.

RESULTS

A consolidated database comprising 788 patients who underwent hepatectomy for CRLM in eight centres was obtained. In multivariable analyses, severe SD was associated with increased major morbidity (Dindo-Clavien grade III-V; OR 1·73, 95 per cent c.i. 1·02 to 2·95; P = 0·043). Severe steatosis was associated with decreased liver surgery-specific complications (OR 0·52, 95 per cent c.i. 0·27 to 1·00; P = 0·049), whereas steatohepatitis was linked to an increase in these complications (OR 2·08, 1·18 to 3·66; P = 0·012). Subgroup analysis showed that lobular inflammation was the sole component associated with increased overall morbidity (OR 2·22, 1·48 to 3·34; P = 0·001) and liver surgery-specific complications (OR 3·35, 2·11 to 5·32; P < 0·001). Finally, oxaliplatin treatment was linked to severe SD (OR 2·74, 1·67 to 4·49; P < 0·001).

CONCLUSION

An increase in postoperative major morbidity and liver surgery-specific complications was observed after partial hepatectomy in patients with severe SD and steatohepatitis. Postoperative liver failure occurred more often in patients with severe SD.

Carbon dioxide laser ablation of basal cell carcinoma with visual guidance by reflectance confocal microscopy: a proof-of-principle pilot study

BACKGROUND

Laser ablation is an alternative, nonsurgical treatment modality for low-risk basal cell carcinoma (BCC). However, lack of confirmative tumour destruction or residual tumour presence has been a limiting factor to its adoption. Reflectance confocal microscopy (RCM) provides noninvasive, cellular-level resolution imaging of the skin and is capable of identifying tumour.

OBJECTIVES

To evaluate the use of RCM to guide carbon dioxide (CO2 ) laser ablation of BCC, confirm destruction and correlate findings with histology.

METHODS

RCM was used preablation to evaluate for features of BCC. Ablation was performed with a CO2 laser, and the response rapidly assessed using handheld RCM to evaluate for residual tumour. Confirmative pathology was used to verify confocal imaging.

RESULTS

Preablation RCM imaging identified tumour with features not identified on normal, surrounding skin. Postablation, RCM documented complete removal of tumour in six cases and residual tumour in two. Histological examination identified the ablated area and confirmed clearance of tumour in the six aforementioned cases and corroborated confocal findings for residual tumour in the other two cases.

CONCLUSIONS

We report successful treatment of superficial and nodular BCC using CO2 laser ablation augmented by RCM imaging for preablation guidance and verification of tumour removal postablation. Akin to complete circumferential and deep margin control techniques, using RCM helps to map peripheral and deep BCC margins to hone in on areas exhibiting persistent tumour after ablation. CO2 laser ablation visually guided by RCM can help circumvent previously cited limiting factors of laser ablation for tumour destruction by providing cellular-level resolution imaging of tumour and margin assessment in between each laser pass and postablation.

Passive cooling to initiate hypothermia for transported encephalopathic newborns

Two newborns at high risk for severe encephalopathy were passively cooled by discontinuing the supplied heat from a radiant warmer. Cooling was attempted in both babies (successfully in one) before the arrival of the neonatal transport team. Both infants had core temperatures of approximately 34 degrees C on arrival at the NICU. Passive cooling may be an effective method to initiate cooling very early in the course of encephalopathy.

Iatrogenic ulnar neuropathies post-pinning of displaced supracondylar humerus fractures in children

A retrospective review of 141 displaced supracondylar fractures in children at the Bustamante Children's Hospital and the University Hospital of the West Indies from 1994 to 1999 revealed ten ulnar nerve palsies. Of the 141 supracondylar fractures, 27 were treated with open reduction and internal fixation, while 114 had closed reduction and percutaneous pinning. All fractures were fixed with crossed Kirschner wires. Of the ten cases, the ulnar nerve was explored in two cases; the medial pin was removed in two cases, while the other six cases were observed. Follow-up ranged from three to 18 months. Full nerve recovery occurred in all cases except one in which there was partial return of function. Recommendations are made regarding the management of these injuries.

Heart failure and apoptosis: electrophoretic methods support data from micro- and macro-arrays. A critical review of genomics and proteomics

The multiple causes and multiple consequences of mammalian heart failure make it an attractive proposition for analysis using gene array technology, especially where the failure is idiopathic in nature. However, gene arrays also hold potential artefacts, particularly when gene expression levels are low, and where changes in expression levels are modest. Also, at present, the number of genes available on arrays is not large enough to prevent potential sampling deficiencies. Thus, it may not be wise to place too much reliance on quantitative interpretations of gene array data. Also, recently doubts were raised about the qualitative reliability of array genes. Electrophoretic methods are slow, cumbersome and complex but they can provide confirmation that the trends and numbers arising from the new gene arrays are reliable. In this overview, we compare gene array data with data from protein activity assays such as zymograms, Western blots, two-dimensional electrophoresis, and immunohistochemistry. Similar or complementary data from the same heart tissues analyzed by either microarrays or macroarrays can be reassuring to those interested in reliable molecular analyses of normal and failing hearts. Similar principles will apply to other tissues and cells.

The bispectral index monitor: a new tool for air medical personnel

The bispectral index monitor (BIS) is commonly used in the operating room to help anesthesiologists quantitate the level of anesthesia. The BIS has been shown to reduce the incidence of anesthetic overuse and decrease costs. The device has made its way into critical care areas, where it has proven effective in monitoring sedation levels, specifically in reducing the incidence of oversedation. This article explores the possibility of using the monitor in the air medical environment.

Receptor-mediated targeting of spray-dried lipid particles coformulated with immunoglobulin and loaded with a prototype vaccine

PURPOSE

Spray-dried lipid-based microparticles (SDLM) serve as a platform for delivery of a wide variety of compounds including peptides, proteins, and vaccines to the respiratory mucosa. In the present study, we assessed the impact of IgG-mediated targeting to phagocytic cells of inactivated influenza virus formulated in SDLM, on subsequent immune responses.

METHODS

SDLM were produced containing inactivated influenza virus strain A/WSN/32/H1N1 (WSN), with or without IgG. Using phagocytic antigen presenting cells (APC) and a T cell hybridoma (TcH) line specific for a dominant influenza virus epitope, we compared the in vitro responses elicited by ligand-formulated (SDLM-IgG-WSN) and non-ligand particles (SDLM-WSN). The effect of including the IgG ligand in the formulation was further characterized by measuring the immune responses of rodents vaccinated with SDLM.

RESULTS

SDLM-IgG-WSN were internalized in an Fc receptor (FcR)-dependent manner by phagocytic APC that were then able to effectively present a dominant, class II-restricted epitope to specific T cells. While SDLM-WSN elicited a lower response than administration of plain inactivated virus in saline, the level of the T cell response was restored both in vitro and in vivo by incorporating the APC FcR ligand, IgG, in the SDLM.

CONCLUSIONS

Incorporation of FcR ligand (IgG) in SDLM restored the limited ability of formulated virus to elicit T-cell immunity, by receptor-mediated targeting to phagocytes.

The effectiveness of the levonorgestrel-releasing intrauterine system in menorrhagia: a systematic review

OBJECTIVE

To determine whether the levonorgestrel-releasing intrauterine device (LNG-IUS), licensed at present for contraceptive use, may reduce menstrual blood loss with few side effects. If effective, surgery could be avoided with consequent resource savings.

METHODS

A systematic review addressing the effectiveness and cost effectiveness of the LNG-IUS for menorrhagia was undertaken.

RESULTS

Five controlled trials and five case series were found which measured menstrual blood loss. Nine studies recorded statistically significant average menstrual blood loss reductions with LNG-IUS (range 74%-97%). Another showed reduction in menstrual disturbance score. The LNG-IUS was more effective than tranexamic acid, but slightly less effective than endometrial resection at reducing menstrual blood loss. In one study, 64% of women cancelled surgery at six months, compared with 14% of control group women. In another, 82% were taken off surgical waiting lists at one year. No cost effectiveness studies were found.

DISCUSSION

Small studies of moderate quality indicate the LNG-IUS is an effective treatment for menorrhagia. Costs may be less than for tranexamic acid in primary and secondary care. Although its use may reduce surgical waiting lists, cost effectiveness assessment requires longer follow up.

CONCLUSION

Effectiveness and cost effectiveness relative to other treatments and the effect on surgical waiting lists can only be established in larger trials measuring patient-centred outcomes in women with menorrhagia.

Linkage disequilibria and the site frequency spectra in the su(s) and su(w(a)) regions of the Drosophila melanogaster X chromosome

Over the last decade, surveys of DNA sequence variation in natural populations of several Drosophila species and other taxa have established that polymorphism is reduced in genomic regions characterized by low rates of crossing over per physical length. Parallel studies have also established that divergence between species is not reduced in these same genomic regions, thus eliminating explanations that rely on a correlation between the rates of mutation and crossing over. Several theoretical models (directional hitchhiking, background selection, and random environment) have been proposed as population genetic explanations. In this study samples from an African population (n = 50) and a European population (n = 51) were surveyed at the su(s) (1955 bp) and su(w(a)) (3213 bp) loci for DNA sequence polymorphism, utilizing a stratified SSCP/DNA sequencing protocol. These loci are located near the telomere of the X chromosome, in a region of reduced crossing over per physical length, and exhibit a significant reduction in DNA sequence polymorphism. Unlike most previously surveyed, these loci reveal substantial skews toward rare site frequencies, consistent with the predictions of directional hitchhiking and random environment models and inconsistent with the general predictions of the background selection model (or neutral theory). No evidence for excess geographic differentiation at these loci is observed. Although linkage disequilibrium is observed between closely linked sites within these loci, many recombination events in the genealogy of the sampled alleles can be inferred and the genomic scale of linkage disequilibrium, measured in base pairs between sites, is the same as that observed for loci in regions of normal crossing over. We conclude that gene conversion must be high in these regions of low crossing over.

The Awkward Moments Test: a naturalistic measure of social understanding in autism

Details are given of a new advanced theory of mind task, developed to approximate the demands of real-life mentalizing in able individuals with autism. Excerpts of films showing characters in social situations were presented, with participants required to answer questions on characters' mental states and on control, nonsocial questions. When compared with control participants, adults with high-functioning autism and Asperger syndrome were most impaired in their ability to answer the questions requiring mind-reading ability. Although the present findings have implications for task modification, such naturalistic, dynamic stimuli are held to offer an important means of studying subtle difficulties in mentalistic understanding.

Comparative effects of two physical activity programs on measured and perceived physical functioning and other health-related quality of life outcomes in older adults

BACKGROUND

Although inactivity is an important contributor to impaired functioning and disability with age, little is known concerning how improvements in physical functioning and well-being in older adults vary with the type of physical activity undertaken.

METHODS

One hundred three adults age 65 years and older, recruited via population-based methods, were randomized to 12 months of community-based, moderate-intensity endurance and strengthening exercises (Fit & Firm) or stretching and flexibility exercises (Stretch & Flex). A combination of class- and home-based exercise formats was used. Measured and self-rated physical performance along with perceived functioning and well-being were assessed pre- and postintervention.

RESULTS

Fit & Firm subjects showed greater 12-month improvements in both measured and self-rated endurance and strength compared to Stretch & Flex subjects. Stretch & Flex subjects reported greater improvements in bodily pain, and Stretch & Flex men evidenced greater improvements in flexibility relative to Fit & Firm subjects. Although overall exercise adherence was high in both exercise conditions (approximately 80%), subjects in both conditions showed better adherence to the home- versus class-based portions of their exercise prescriptions.

CONCLUSIONS

Community-based programs focusing on moderate-intensity endurance and strengthening exercises or flexibility exercises can be delivered through a combination of formats that result in improvement in important functional and well-being outcomes. This represents one of the first studies to report significant improvements in an important quality of life outcome-bodily pain-with a regular regimen of stretching and flexibility exercises in a community-based sample of older adults.

Analysis of the detective quantum efficiency of a developmental detector for digital mammography

We are developing a modular detector for applications in full field digital mammography and for diagnostic breast imaging. The detector is based on a design that has been refined over the past decade for applications in x-ray crystallography [Kalata et al., Proc. SPIE 1345, 270-279 (1990); Phillips et al. ibid. 2009, 133-138 (1993), Phillips et al., Nucl. Instrum. Methods Phys. Rev. A 334, 621-630 (1993)]. The full field mammographic detector, currently undergoing clinical evaluation, is formed from a 19 cm x 28 cm phosphor screen, read out by a 2 x 3 array of butted charge-coupled device (CCD) modules. Each 2k x 2k CCD is optically coupled to the phosphor via a fiber optic taper with dimensions of 9.4 cm x 9.4cm at the phosphor. This paper describes the imaging performance of a two-module prototype, built using a similar design. In this paper we use cascaded linear systems analysis to develop a model for calculating the spatial frequency dependent noise power spectrum (NPS) and detective quantum efficiency (DQE) of the detector using the measured modulation transfer function (MTF). We compare results of the calculation with the measured NPS and DQE of the prototype. Calculated and measured DQEs are compared over a range of clinically relevant x-ray exposures and kVps. We find that for x-ray photon energies between 10 and 28 keV, the detector gain ranges between 2.5 and 3.7 CCD electrons per incident x-ray, or approximately 5-8 electrons per absorbed x ray. Using a Mo/Mo beam and acrylic phantom, over a detector entrance exposure range of approximately 10 to 80 mR, the volume under the measured 2-d NPS of the prototype detector is proportional to the x-ray exposure, indicating quantum limited performance. Substantial agreement between the calculated and measured values was obtained for the frequency and exposure dependent NPS and DQE over a range of tube voltage from 25 to 30 kVp.

Transgenic tomato plants with decreased sucrose synthase are unaltered in starch and sugar accumulation in the fruit

Sucrose is the photoassimilate transported from the leaves to the fruit of tomato yet the fruit accumulates predominantly glucose and fructose. Hydrolysis of sucrose entering the fruit can be accomplished by invertase or sucrose synthase. Early in tomato fruit development there is a transient increase in sucrose synthase activity and starch which is correlated with fruit growth and sink strength suggesting a regulatory role for sucrose synthase in sugar import. Using an antisense sucrose synthase cDNA under the control of a fruit-specific promoter we show that sucrose synthase activity can be reduced by up to 99% in young fruit without affecting starch or sugar accumulation. This result calls into question the importance of sucrose synthase in regulating sink strength in tomato fruit.

Data collection in continence care

Evaluation is an important component of any project. However, where change is complex and the time and resources available for collecting data are scarce, considerable thought needs to be given to how evaluation is best carried out. This article discusses some of the issues that arose during the setting up of a service to promote continence.

A novel kainate receptor ligand [3H]-(2S,4R)-4-methylglutamate: pharmacological characterization in rabbit brain membranes

Since kainate evokes large non-desensitizing currents at alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptors, kainate is of limited use in discriminating between AMPA and kainate receptors. Following recent reports that (2S,4R)-4-methylglutamate is a kainate receptor-selective agonist, we have radiolabelled and subsequently characterized the binding of [3H]-(2S,4R)-4-methylglutamate to rabbit whole-brain membranes. [3H]-(2S,4R)-4-methylglutamate binding was rapid, reversible and labelled two sites (KD1 = 3.67+/-0.50 nM/Bmax1 = 0.54+/-0.03 pmol/mg protein and KD2 = 281.66+/-12.33 nM/ Bmax2 = 1.77+/-0.09 pmol/mg protein). [3H]-(2S,4R)-4-methylglutamate binding was displaced by several non-NMDA receptor ligands: domoate > kainate >> L-quisqualate > or = L-glutamate > 6-cyano-7-nitroquinoxaline-2,3-dione (CNQX) >> (S)-AMPA = (S)-5-fluorowillardiine > NMDA. Neither the metabotropic glutamate receptor agonists (1S,3R)-ACPD or L-AP4, together with the L-glutamate uptake inhibitor L-trans-2,4-PDC, influenced binding when tested at 100 microM. We conclude that [3H]-(2S,4R)-4-methylglutamate is a useful radioligand for labelling kainate receptors. It possesses high selectivity, and possesses a pharmacology similar to that for rat cloned low-affinity (Glu5 and 6) kainate receptor subunits.

Human CD34+ hematopoietic progenitors have low, cytokine-unresponsive O6-alkylguanine-DNA alkyltransferase and are sensitive to O6-benzylguanine plus BCNU

Human bone marrow (BM) cells contain low levels of the DNA repair protein, O6-alkylguanine-DNA alkyltransferase, which may explain their susceptibility to nitrosourea-induced cytotoxicity and the development of secondary leukemia after nitrosourea treatment. Isolated CD34+ myeloid progenitors were also found to have low levels of alkyltransferase activity. The level of alkyltransferase in CD34+ cells or in mononuclear BM cells did not increase after incubation with granulocyte-macrophage colony-stimulating factor, interleukin-3, stem cell factor, the combination, or 5637 conditioned medium. BCNU sensitivity remained unchanged as well. In addition, O6-benzylguanine depleted alkyltransferase activity in BM cells at concentrations as low as 1.5 mumol/L after a 1-hour exposure. O6-benzylguanine pretreatment markedly sensitized hematopoietic progenitor colony-forming cells to BCNU, resulting in a reduction in the dose of drug (termed the dose-modification factor) required to inhibit 50% of the colony formation (IC50) of threefold to fivefold. Since, unlike many other cell types, proliferating early (CD34+) hematopoietic precursors do not induce alkyltransferase, myelosuppression may be the dose-limiting toxicity of the combination of O6-benzylguanine plus BCNU in clinical trials.

Theobroma cacao L.: a genetic linkage map and quantitative trait loci analysis

A genetic linkage map of Theobroma cacao (cocoa) has been constructed from 131 backcross trees derived from a cross between a single tree of the variety Catongo and an F1 tree from the cross of Catongo by Pound 12. The map comprises 138 markers: 104 RAPD loci, 32 RFLP loci and two morphologic loci. Ten linkage groups were found which cover 1068 centimorgans (cM). Only six (4%) molecular-marker loci show a significant deviation from the expected 1∶1 segregation ratio.The average distance between two adjacent markers is 8.3 cM. The final genome-size estimates based on two-point linkage data ranged from 1078 to 1112 cM for the cocoa genome. This backcross progeny segregates for two apparently single gene loci controlling (1) anthocyanidin synthesis (Anth) in seeds, leaves and flowers and (2) self-compatibility (Autoc). The Anth locus was found to be 25 cM from Autoc and two molecular markers co-segregate with Anth. The genetic linkage map was used to localize QTLs for early flowering, trunk diameter, jorquette height and ovule number in the BC1 generation using both single-point ANOVA and interval mapping. A minimum number of 2-4 QTLs (P<0.01) involved in the genetic expression of the traits studied was detected. Coincident map locations of a QTL for jorquette height and trunk diameter suggests the possibility of pleiotropic effects in cocoa for these traits. The combined estimated effects of the different mapped QTLs explained between 11.2% and 25.8% of the phenotypic variance observed in the BC1 population.

Behavioral and cognitive effects of methylxanthines. A meta-analysis of theophylline and caffeine

BACKGROUND

Theophylline has been extensively studied as a treatment of asthma. However, some studies have suggested that theophylline may precipitate adverse behavioral and cognitive effects on children. Other reports have evaluated the effects of caffeine, another commonly used methylxanthine, as a treatment of attention-deficit hyperactivity disorder.

OBJECTIVE

To present a meta-analysis of research on the behavioral and cognitive effects of methylxanthines in children.

METHODS

The meta-analyses were conducted on 12 studies of theophylline and nine studies of caffeine that met inclusion criteria.

RESULTS

In contrast to popular beliefs and earlier scientific reports, meta-analyses of controlled studies did not indicate that either theophylline or caffeine resulted in significant deleterious effects on cognition or behavior. In fact, there was a small, positive effect on parental report of externalizing behavior for both methylxanthines.

CONCLUSIONS

There is little evidence to suggest that methylxanthines have adverse cognitive or behavioral effects on children. Questions remain with regard to the identification and determinants of either responsive or sensitive subgroups, dose-response relationships, and the effects of parent-teacher expectancies on behavioral ratings.

Human colour discrimination based on a non-parvocellular pathway

BACKGROUND

Traditionally, colour information is assumed to be carried by neural channels in the parvocellular pathway and to be encoded in an opponent manner, while other, non-parvocellular, spectrally non-opponent channels are thought to play no part in colour vision. But is the parvocellular pathway the only way that colours can be discriminated in human vision? We studied two patients with cerebral achromatopsia, who lack conscious colour perception but are nevertheless able to make use of colour information. In particular, we investigated whether, in these patients, colour discrimination is mediated by the parvocellular pathway.

RESULTS

The achromatopsic patients carried out a forced-choice colour- and luminance-discrimination task, and showed clear evidence of unconscious colour processing, consistent with previous studies. We added different types of luminance noise to see when this unconscious colour information could be masked. The results of the colour-discrimination-with-noise and the brightness-non-additivity experiments showed a double-dissociation between patients. This indicates that, in one patient, unconscious colour discrimination may be subserved by a spectrally non-opponent mechanism, which does not have the characteristics of the parvocellular pathway and which is responsive to fast flicker. Spectral sensitivity, contrast sensitivity and motion perception experiments confirmed that this patient lacks a working opponent parvocellular system. The second achromatopsic patient showed evidence of a residual parvocellular system.

CONCLUSIONS

Our results show that chromatic discrimination need not be mediated by neural mechanisms, the parvocellular system in particular, normally assumed to subserve conscious colour perception. Such discrimination may be mediated by a neural subsystem which responds to fast flicker, is spectrally non-opponent, and supports normal motion perception.

Autism: towards an integration of clinical, genetic, neuropsychological, and neurobiological perspectives

Autism constitutes one of the best validated child psychiatric disorders. Empirical research has succeeded in delineating the key clinical phenomena, in demonstrating strong genetic influences on the underlying liability, and in identifying basic cognitive deficits. A range of neurobiological abnormalities has also been found, although the replicability of specific findings has not been high. An understanding of the causal processes leading to autism, and accounting for the marked variability in its manifestations, requires an integration across these different levels of enquiry. Although this is not yet possible, a partial integration provides a useful strategy for identifying key research questions, the limitations of existing hypotheses, and future research directions that are likely to prove fruitful. The research findings for each research level are critically reviewed in order to consider how to move towards an integration across levels.

Strength and muscle mass changes in elderly men following maximal isokinetic training

The purpose of this study was to determine the effects of a maximal isokinetic training program on strength and muscle mass in a group of untrained men 73 +/- 7.3 (range 68-82) years of age. Testing and training were conducted on an isokinetic dynamometer. Training consisted of one set of six maximal knee flexion and extension movements at 60 deg*s(-1) performed three times per week for 12 weeks. The subjects trained the right leg only, the left leg serving as a within-subject control. Trained leg peak torque increased by 18.1% for knee extension (from 107.2 +/- 42.9 to 126.6 +/- 44.6 Nm; p < 0.05) and by 18.2% for knee flexion (from 85.1 +/- 21.1 to 100.4 + or - 25.5 Nm; p < 0.05). Urinary creatinine levels increased by 24.3% (NS). We conclude that maximal isokinetic training at 60 deg*s(-1) increases strength and a urinary index of muscle mass in a group of aged untrained men.

Treating people as objects, agents, or "subjects": how young children with and without autism make requests

A procedure previously used to investigate imperative communication in non-human primates was applied to young children, some of whom had autism. The goal was to examine closely how requests are made in a problem-solving situation. Each child's spontaneous strategies to obtain an out-of-reach object were analyzed in terms of the ways in which he or she used the adult who was present. Results showed that fewer children with autism used a strategy of treating the person as a "subject", and that more children with autism used object-centred strategies.

Frequent use of medical services. Patient reports of intentions to seek care

OBJECTIVE

To examine differences between frequent and infrequent users in decisions to seek medical care based on symptom type and duration of experience of the symptom.

DESIGN

Retrospective study.

SETTING

University family practice clinic.

PATIENTS

Fifty-eight of 130 patients returned the completed instruments, a response rate of 45%.

MAIN OUTCOME MEASURES

The following two instruments were used: the Intentions to Seek Care questionnaire, which measures intention to see a physician, self-treat, or use medications for 11 different symptoms after three time periods--1 day, 3 days, and 1 week of symptom duration--and the SF-36 Health Survey measure.

RESULTS

Initial analyses suggested that patients perceive three clusters of symptoms, which we have labeled as serious, mild, and psychological. Scale scores for these groups of symptoms yielded significant reliability and were used in subsequent analyses. Multivariate analysis of variance comparing source of care, symptom duration, and frequent vs infrequent user groups indicated that both user groups are more likely to seek care from physicians for symptoms that are serious. Analysis of mild and psychological symptoms yielded significant three-way interactions, with frequent users more likely than infrequent users to seek care from physicians at a 1-day duration. Such differences disappear by 7 days. Significantly lower scores were obtained on five of the eight SF-36 Health Survey dimensions for the infrequent users.

CONCLUSIONS

Frequent users are more likely than infrequent users to report that they would seek care for minor symptoms. Infrequent users tend to self-treat for 3 to 7 days, after which time physician advice is sought. Efforts to teach patients optimal timing of use for different symptoms may be an effective intervention.

Arm crank exercise with static leg FNS in persons with spinal cord injury

Persons with spinal cord injury experience considerable difficulty, during aerobic exercise, in achieving even moderate levels of oxygen uptake. Therefore, the effect of static functional neuromuscular stimulation (FNS) on this parameter during arm crank exercise (ACE) was investigated. Eight subjects with spinal cord injury, lesion levels range C6-T12, performed ACE at 60% and 80% of VO2peak, both with and without concurrent FNS of the lower limbs. ACE was performed with no FNS, with FNS at 40 milliamperes (mA), and with FNS at 80 mA. Significant differences in oxygen uptake were found between ACE without FNS and ACE with FNS-80 mA at 60% VO2peak (10% increase, 12.5 ml.kg-1.min-1 to 13.7 ml.kg-1.min-1, P < 0.05), and between ACE without FNS and ACE with FNS-80 mA at 80% VO2peak (16%, increase, 14.8 ml.kg-1.min-1 to 17.2 ml.kg-1.min-1, P < 0.01). A 10% difference between ACE without FNS and ACE with FNS-40 mA, did not reach significance. These data indicate that, in this population of subjects with spinal cord injury, (a) FNS can increase submaximal ACE oxygen uptake, and (b) that such increases are enhanced both at higher levels of FNS and of work load. Implications for wellness are discussed.

Relative changes in blood flow with functional electrical stimulation during exercise of the paralyzed lower limbs

Eight spinal cord injured (SCI) patients performed three sets of exercise with two conditions, 60% and 80% of VO2peak, with an arm crank ergometer. Functional neuromuscular stimulation was used to induce static leg contractions in two of the above sets of exercise. The three exercise sets were performed with no functional neuromuscular stimulation (NOS); with functional neuromuscular stimulation at 40 milliamperes; and with functional neuromuscular stimulation at 80 milliamperes (HIS). The lower limb blood flow was estimated by a photoelectric plethysmograph. Results showed that the lower limb blood flow was consistently reduced across both functional neuromuscular stimulation levels (17.4% from NOS to LOS; 13.8% from LOS to HIS; and 28.8% from NOS to HIS), and work loads (15.3% from rest to 60% VO2peak; 38.0% from 60% VO2peak to 80% VO2peak; and 47.5% from rest to 80% VO2peak). Rate-pressure product was decreased by 8.3% between NOS and HIS at 60% VO2peak (15.7 +/- 3.4 to 14.4 +/- 3.8), by 6.8% between NOS and HIS at 80% VO2peak (18.9 +/- 53 to 17.6 +/- 4.8), and by 12.4% between LOS and HIS at 80% VO2peak (20.1 +/- 6.7 to 17.6 +/- 4.8). These data indicate that in SCI (a) functional neuromuscular stimulation-induced contractions of the lower limb muscles can increase blood flow and thus reduce venous blood pooling in the paralyzed muscles, and (b) such improvements are associated with a reduced rate pressure product.(ABSTRACT TRUNCATED AT 250 WORDS)

The association of assimilation and an increase in visibility in perceptual grouping

Subjects performed a series of forced-choice discriminations to determine whether both group-assimilation and group-visibility associations could be obtained from nearly identical strong and weak group patterns. The discrimination between the context+target square and the context [symbol: see text] was better than between the target- and background, as was the case for --, whose context and target components were its left and right halves, but not for [symbol: see text]. Square and -- produced a better performance when their lines (halves) were the same in color, and a poorer performance when their lines were different in color, but [symbol: see text] produced the reverse. Likewise, only square and -- produced a better performance when closed, and a poorer performance when open. These context+target etc., same-different, and closure results argue that square and -- produced a greater increase in visibility of their component --, more assimilation among their parts, and a stronger group than did [symbol: see text]. This evidence of a group-assimilation-visibility association cannot be attributed to the fortuitous occurrence of an increase in visibility with one object, assimilation with a second, and closure with a third, unlike previous evidence. This association cannot be explained by feature-based theories. Therefore, a superordinate unit is the cause of this association.

Low intelligence but not attention deficit hyperactivity disorder is associated with resistance to thyroid hormone caused by mutation R316H in the thyroid hormone receptor beta gene

Resistance to thyroid hormone (RTH) is a syndrome of reduced responsiveness of tissues to thyroid hormone. The clinical manifestations are variable and 46-50% of children with RTH have attention deficit hyperactivity disorder (ADD). We present a new family with RTH (F120) found to have a mutation R316H in the thyroid hormone receptor beta (TR beta) gene identical for that reported in an unrelated family. Assignment of the mutant allele and haplotyping based on CA repeat polymorphism were done on 16 family members. Semistructured diagnostic interviews and psychometric testing were used to determine the psychiatric diagnosis of 12 family members by examiners blinded to the genotype. Three subjects were identified to have the R316H allele as well as mildly elevated free T4 index (168 +/- 12; normal range 77-135) and nonsuppressed TSH (4.1 +/- 1.7 mU/L). Only 2 of the subjects with RTH were found to have ADD, while one family member homozygous for the wild type TR beta and normal thyroid function tests also had ADD. Unaffected family members had higher full scale intelligence quotients (IQ) (93 +/- 7) than any of the 3 family members with RTH (77 +/- 5, p = 0.006). These data do not support the genetic linkage of ADD and RTH, but do suggest that RTH is associated with lower IQ scores that may confer a high likelihood of exhibiting ADD symptoms.

Psychometric properties of the children's atypical development scale

The Children's Atypical Development Scale (CADS) is a 53-item rating scale designed to measure unusual behaviors in children. Principal-factor analysis on a clinic-referred and pediatric sample of 474 children resulted in a four-factor solution: Communication Deficits, Lability, Social Relatedness Deficits, and Preoccupation. The CADS is internally consistent and has adequate temporal stability. CADS factor scores were differentially associated with parent and teacher rating scales, IQ, and Continuous Performance Test errors. The scale shows promise as a clinical and research tool for assessing atypical behaviors associated with pervasive developmental disorder and other neurobehavioral disorders.