Nosocomial infections: validation of surveillance and computer modeling to identify patients at risk

To estimate the accuracy of routine hospital-wide surveillance for nosocomial infection, the authors performed a validation study at the University of Iowa Hospitals and Clinics, a 900-bed tertiary care institution, by daily concurrent surveys of all patients' charts. The study extended over a 10-month period from January to October 1987. The sensitivity and specificity of the reported data were 80.7% (95% confidence interval (CI) 72.2-89.2) and 97.5% (95% CI 96.4-98.5), respectively. The predictive values of positive or negative reports of an infection were 75.3% (95% CI 66.3-84.2) and 98.1% (95% CI 97.3-99.1), respectively. In a separate analysis, the data entry system was reviewed for eight descriptive variables among all patients with infections (n = 443) identified over a 2-month period. The data entry was found to be 94-99% accurate. To improve the efficiency of current surveillance, the authors used data gathered during the study to develop a computer model for the identification of patients with a high probability of having a nosocomial infection. The use of stepwise logistic regression identified five variables which independently predicted infection: age of the patient (years), days of antibiotics, days of hospitalization, and the number of days on which urine and/or wound cultures were obtained. Optimal sensitivity and specificity (81.6% and 72.5%, respectively) were found when the model examined patients with an 8% or higher a priori probability of infection; this figure corresponded to a review of 33% of the patients' charts. Increasing the a priori probability would progressively increase specificity and reduce both sensitivity and the number of charts needed for review. If it is prospectively validated, the model may provide a more efficient mechanism by which to conduct hospital-wide surveillance.

Chemical patterning and physical refinement of reactive superhydrophobic surfaces

An approach to the modification and post-fabrication chemical patterning of amine-reactive superhydrophobic surfaces is reported. The approach is based on the layer-by-layer fabrication of azlactone-containing polymer multilayers, and permits the direct covalent attachment and subsequent patterning of chemical and biological "inks" using a variety of practical and low-cost pattern-transfer methods.

Fabrication and selective functionalization of amine-reactive polymer multilayers on topographically patterned microwell cell culture arrays

We report an approach to the fabrication and selective functionalization of amine-reactive polymer multilayers on the surfaces of 3-D polyurethane-based microwell cell culture arrays. "Reactive" layer-by-layer assembly of multilayers using branched polyethyleneimine (BPEI) and the azlactone-functionalized polymer poly(2-vinyl-4,4'-dimethylazlactone) (PVDMA) yielded film-coated microwell arrays that could be chemically functionalized postfabrication by treatment with different amine-functionalized macromolecules or small molecule primary amines. Treatment of film-coated arrays with the small molecule amine d-glucamine resulted in microwell surfaces that resisted the adhesion and proliferation of mammalian fibroblast cells in vitro. These and other experiments demonstrated that it was possible to functionalize different structural features of these arrays in a spatially resolved manner to create dual-functionalized substrates (e.g., to create arrays having either (i) azlactone-functionalized wells, with regions between the wells functionalized with glucamine or (ii) substrates with spatially resolved regions of two different cationic polymers). In particular, spatial control over glucamine functionalization yielded 3-D substrates that could be used to confine cell attachment and growth to microwells for periods of up to 28 days and support the 3-D culture of arrays of cuboidal cell clusters. These approaches to dual functionalization could prove useful for the long-term culture and maintenance of cell types for which the presentation of specific and chemically well-defined 3-D culture environments is required for control over cell growth, differentiation, and other important behaviors. More generally, our approach provides methods for the straightforward chemical functionalization of otherwise unreactive topographically patterned substrates that could prove to be useful in a range of other fundamental and applied contexts.

New method to prepare autologous fibrin glue on demand

Fibrin-based sealants are commonly employed to arrest bleeding after surgery. Usually, fibrinogen obtained from pooled human plasma is used to prepare sealants, with attendant risk of blood-borne infections. Availability of autologous fibrinogen would eliminate this risk. To prepare autologous fibrin sealant, fibrinogen was precipitated from human plasma using protamine. Under optimal conditions (10-mg/mL protamine and 22 degrees C), 96 +/- 4% of clottable fibrinogen was recovered by a simple and inexpensive technique. Nearly 50% of the plasma factor XIII was also recovered with the fibrinogen. Using bovine thrombin, the fibrinogen was clotted (1) in a specially designed mold to measure tensile strength and (2) in a lap joint between 2 aortic vessel strips to measure adhesion strength. Tensile and adhesion strengths increased with increasing fibrinogen concentration, and they were increased by the addition of calcium chloride. The addition of aprotinin and -aminocaproic acid to the fibrinogen concentrate before clotting had no effect on the mechanical properties of the clots. After adding thrombin to sealant containing 15-mg/mL fibrinogen, maximum tensile strength was achieved in 1-5 min, and maximum adhesion strength was reached in 5-15 min. For the sealant with 30-60-mg/mL fibrinogen and added calcium, the tensile strength was equivalent to that of the commercial fibrin sealant Tisseel. The adhesion strength of sealant with 30-60-mg/mL fibrinogen exceeded the adhesive strength of Tisseel under identical conditions. Autologous fibrin sealant is an attractive alternative to commercial sealants. It can be readily prepared from 5-mL plasma or more and exhibits mechanical properties equivalent to those of the leading commercial sealant.

Motor activity and perception of sleep in depressed patients

Subjectively experienced sleep patterns often differ from observed sleeping behavior in insomniacs. Sleep patterns have been evaluated by measurements of motor activity in healthy subjects and insomniacs, but results may depend on the insomnia subtype. Sleep disturbances are frequent complaints in depression, but the influence of psychopathology on activity measurements remains elusive. Therefore, the relationship between reported sleep complaints and motor activity was studied in patients with major depression. Severity of depression was documented in depressed inpatients by observer-(HAMD) and self-rated scales (DACL, SHAPS-D). Self-reports of sleep were obtained by Pittsburgh Sleep Quality Index (PSQI) and daily sleep logs (DSL). Motor activity was continuously recorded over 72 h by actigraphy. 'Good' sleepers showed less motor activity during the night compared to 'poor' sleepers (p<0.01). Patients with high HAMD scores (> or = 18) showed greater nocturnal motor activity and less sleep quality compared to patients with low HAMD scores (p<0.01). When controlling for age and severity of depression, partial correlation was found to be significant between perceived daily sleep quality and nocturnal motor activity (r = -0.63, p<0.01). There was a significant effect of nocturnal motor activity as a covariate on disturbances of subjective sleep quality and severity of depression as the main effect (p<0.01). In depressed patients, nocturnal motor activity seems to be an indicator of experienced sleep disturbances. The results warrant further controlled studies to evaluate the role of psychological factors for objective measurements and subjective perception of sleep patterns.

Motor activity and daily variation of symptom intensity in depressed patients

Spontaneous motor activity measured by actigraphy and subjectively experienced intensity of symptoms were investigated in 16 unipolar depressed inpatients with melancholic features. Patients felt significantly less active, awake, and more depressed in the morning compared to the evening. However, morning activity levels appeared significantly higher compared to evening levels. Diurnal variations of symptoms were reflected by actigraphically measured motor activity, which was negatively correlated with subjectively experienced symptom intensity. Increased motor activity may represent an observable, psychobiological, behavioral equivalent of self-experienced depressive symptoms in major depression with melancholic features.

Pleural determinants of restrictive lung function and respiratory symptoms in an asbestos-exposed population

To further define the relationship between asbestos-induced pleural fibrosis and restrictive lung function, we investigated the pleural determinants of respiratory symptoms and restrictive physiology in 1,211 sheet metal workers. We evaluated the relationship between specific components of pleural fibrosis (costophrenic angle involvement, diaphragmatic plaques, width and length of pleural fibrosis, pleural calcification, and the type of fibrosis-circumscribed plaque or diffuse pleural thickening) and both forced vital capacity and respiratory symptoms. We found that costophrenic angle involvement, the width and length of pleural fibrosis, and the presence of either circumscribed plaque or diffuse pleural thickening were each significantly associated with a lower FVC. No consistent relationship was observed between FVC and either diaphragmatic plaques or pleural calcification. However, since the pleural abnormalities were highly collinear, none of these abnormalities alone or in combination predicted the reduction in FVC significantly better than a model that included circumscribed plaques and diffuse pleural thickening. We also investigated the relationship of each component of pleural fibrosis with cough, dyspnea, and chest pain. After controlling for appropriate confounders, a trend toward significance was observed between increased width and length of fibrosis and dyspnea with exertion. Otherwise, these pleural abnormalities were not consistently related to any of the three respiratory symptoms. Our results indicate that although pleural plaques and diffuse pleural thickening and their components are independently associated with a lower FVC, these components of pleural fibrosis do not substantially improve the previously defined relationship between FVC and both circumscribed plaques and diffuse pleural thickening. In addition, a trend toward significance was observed between the width and length of the pleural abnormality and dyspnea while hurrying.

Surface-mediated release of a synthetic small-molecule modulator of bacterial quorum sensing: gradual release enhances activity

We demonstrate an approach to the surface-mediated release of a synthetic N-acylated L-homoserine lactone (AHL) modulator of bacterial quorum sensing (QS). AHL released gradually from thin films of poly(lactide-co-glycolide) (PLG) is shown to activate QS in the model symbiont Vibrio fischeri at levels that exceed those promoted by direct solution-based administration.

Functionalization of reactive polymer multilayers with RGD and an antifouling motif: RGD density provides control over human corneal epithelial cell-substrate interactions

Our study demonstrates that substrates fabricated using a "reactive" layer-by-layer approach promote well-defined cell-substrate interactions of human corneal epithelial cells. Specifically, crosslinked and amine-reactive polymer multilayers were produced by alternating "reactive" deposition of an azlactone-functionalized polymer [poly(2-vinyl-4,4-dimethylazlactone)] (PVDMA) and a primary amine-containing polymer [branched poly(ethylene imine)] (PEI). Advantages of our system include a 5- to 30-fold decrease in deposition time compared to traditional polyelectrolyte films and direct modification of the films with peptides. Our films react with mixtures of an adhesion-promoting peptide containing Arg-Gly-Asp (RGD) and the small molecule D-glucamine, a chemical motif which is nonfouling. Resulting surfaces prevent protein adsorption and promote cell attachment through specific peptide interactions. The specificity of cell attachment via immobilized RGD sequences was verified using both a scrambled RDG peptide control as well as soluble-RGD competitive assays. Films were functionalized with monotonically increasing surface densities of RGD which resulted in both increased cell attachment and the promotion of a tri-phasic proliferative response of a human corneal epithelial cell line (hTCEpi). The ability to treat PEI/PVDMA films with peptides for controlled cell-substrate interactions enables the use of these films in a wide range of biological applications.

Surface-mediated release of a small-molecule modulator of bacterial biofilm formation: a non-bactericidal approach to inhibiting biofilm formation in Pseudomonas aeruginosa

We report an approach to preventing bacterial biofilm formation that is based on the surface-mediated release of 5,6-dimethyl-2-aminobenzimidazole (DMABI), a potent and non-bactericidal small-molecule inhibitor of bacterial biofilm growth. Our results demonstrate that DMABI can be encapsulated in thin films of a model biocompatible polymer [poly(lactide-co-glycolide), PLG] and be released in quantities that inhibit the formation of Pseudomonas aeruginosa biofilms by up to 75-90% on surfaces that otherwise support robust biofilm growth. This approach enables the release of this new anti-biofilm agent for over one month, and it can be used to inhibit biofilm growth on both film-coated surfaces and other adjacent surfaces (e.g., on other uncoated surfaces and at air/water interfaces). Our results demonstrate a non-bactericidal approach to the prevention of biofilm growth and provide proof of concept using a clinically relevant human pathogen. In contrast to coatings designed to kill bacteria on contact, this approach should also permit the design of strategically placed depots that disseminate DMABI more broadly and exert inhibitory effects over larger areas. In a broader context, the non-bactericidal nature of DMABI could also provide opportunities to address concerns related to evolved resistance that currently face approaches based on the release of traditional microbicidal agents (e.g., antibiotics). Finally, the results of initial in vitro mammalian cell culture studies indicate that DMABI is not toxic to cells at concentrations required for strong anti-biofilm activity, suggesting that this new agent is well suited for further investigation in biomedical and personal care contexts.

Surface coatings that promote rapid release of peptide-based AgrC inhibitors for attenuation of quorum sensing in Staphylococcus aureus

Staphylococcus aureus is a major human pathogen responsible for a variety of life-threatening infections. The pathogenicity of this organism is attributed to its ability to produce a range of virulence factors and toxins, including the superantigen toxic shock syndrome toxin-1 (TSST-1). While many S. aureus infections can be treated using conventional antibiotics, strains resistant to these bactericidal agents have emerged. Approaches that suppress pathogenicity through mechanisms that are nonbactericidal (i.e., antivirulence approaches) could provide new options for treating infections, including those caused by resistant strains. Here, we report a nonbactericidal approach to suppressing pathogenicity based on the release of macrocyclic peptides (1 and 2) that inhibit the agr quorum sensing (QS) circuit in group-III S. aureus. It is demonstrated that these peptides can be immobilized on planar and complex objects (on glass slides, nonwoven meshes, or within absorbent tampons) using the rapidly dissolving polymer carboxymethylcellulose (CMC). Peptide-loaded CMC films released peptide rapidly (<5 min) and promoted strong (>95%) inhibition of the agr QS circuit without inducing cell death when incubated in the presence of a group-III S. aureus gfp-reporter strain. Peptide 1 is among the most potent inhibitors of QS in S. aureus reported to date, and the group-III QS circuit regulates production of TSST-1, the primary cause of toxic shock syndrome (TSS). These results thus suggest approaches to treat the outer covers of tampons, wound dressings, or other objects to suppress toxin production and reduce the severity of TSS in clinical and personal care contexts. Because peptide 1 also inhibits QS in S. aureus groups-I, -II, and -IV, this approach could also provide a pathway for attenuation of QS and associated virulence phenotypes in a broader range of contexts.

Asbestos-induced pleural fibrosis and impaired exercise physiology

To further assess the clinical significance of asbestos-induced pleural fibrosis, we performed cardiopulmonary exercise testing in 90 subjects who were exposed to asbestos. Of the 82 subjects without an abnormal resperate exercise, 35 had normal pleura, 33 had circumscribed pleural plaques, and 14 had diffuse pleural thickening. Interstitial fibrosis (International Labor Organization [ILO]. > or = 1/10) was present in 14 of 35 subjects with normal pleura, 13 of 33 subjects with circumscribed pleural plaques, and 2 of 14 subjects with diffuse pleural thickening. Although pleural fibrosis did not appear to be related to impaired respiratory function with exercise in our entire cohort, this finding was confounded by a higher proportion of interstitial fibrosis in subjects with normal pleura. In fact, among study subjects without asbestosis, significant decreases in gas exchange (higher VD/VT and increased alveolar-arterial oxygen pressure difference) were observed at maximal exercise among subjects with pleural fibrosis. Interestingly, neither a higher respiratory rate nor a lower VT/FVC ratio was observed among those with pleural fibrosis, suggesting that the mechanical effects of pleural fibrosis on the chest wall do not explain the increased VD/VT. Using multivariate analyses to control for potential confounders, regression models showed that pleural plaques (p = 0.04) and diffuse pleural thickening (p = 0.03) were independently associated with significant increases in dead space ventilation (VD/VT) with maximal exercise. These findings indicate that asbestos-induced pleural fibrosis is independently associated with decrements in gas exchange with maximal exercise and suggest that interstitial lung disease, not detected on the routine chest x-ray film, may be responsible for this abnormal response to exercise.

Nanoimprinted thin films of reactive, azlactone-containing polymers: combining methods for the topographic patterning of cell substrates with opportunities for facile post-fabrication chemical functionalization

Approaches to the fabrication of surfaces that combine methods for the topographic patterning of soft materials with opportunities for facile, post-fabrication chemical functionalization could contribute significantly to advances in biotechnology and a broad range of other areas. Here, we report methods that can be used to introduce well-defined nano- and microscale topographic features to thin films of reactive polymers containing azlactone functionality using nanoimprint lithography (NIL). We demonstrate that NIL can be used to imprint topographic patterns into thin films of poly(2-vinyl-4,4-dimethylazlactone) and a copolymer of methyl methacrylate and 2-vinyl-4,4-dimethylazlactone using silicon masters having patterns of grooves and ridges ranging in width from 400 nm to 2 microm, demonstrating the potential of this method to transfer patterns to films of these reactive polymers over a range of feature sizes and densities. We demonstrate further that the azlactone functionality of these polymers survives temperatures and pressures associated with NIL, and that topographically patterned films can be readily functionalized post-fabrication by treatment of surface-accessible azlactone functionality with small molecules and polymers containing primary amines. The results of experiments in which NIH-3T3 cells were seeded onto films imprinted with lined patterns having a pitch of 4 microm demonstrated that cells attach and proliferate on these azlactone-containing films and that they align in the direction of the imprinted pattern. Finally, we demonstrate that the treatment of these materials with amine-functionalized poly(ethylene glycol) (PEG) can be used to create regions of topographically patterned films that prevent cell adhesion. The results of this study suggest approaches to the functionalization of topographically patterned surfaces with a broad range of chemical functionality (e.g., peptides, proteins, carbohydrates, etc.) of biotechnological interest. The ability to manipulate and define both the physical topography and chemical functionality of these reactive materials could provide opportunities to investigate the combined effects of substrate topography and chemical functionality on cell behavior and may also be useful in a broad range of other applications.

A rising incidence and poorer male outcomes characterise early onset paediatric inflammatory bowel disease

BACKGROUND

The incidence of paediatric inflammatory bowel disease diagnosed before age 10 years is reportedly increasing, but national data are limited.

AIM

To characterise the epidemiology, phenotype and clinical outcomes of children diagnosed with inflammatory bowel disease before age 10 years, and compare with data from children diagnosed aged 10-16 years.

METHODS

A review of all Irish cases of early onset inflammatory bowel disease (diagnosis <10 years, EO-IBD) presenting between January 2000 and December 2014 was undertaken and compared to a cohort of later onset paediatric inflammatory bowel disease patients (diagnosis between 10 and 16 years, LO-IBD). Diagnostic investigations, phenotype, treatments, and long-term clinical and surgical outcomes were analysed.

RESULTS

One hundred and ninety children (99 male) with EO-IBD were identified; 92 (48%) CD, 77 (41%) UC and 21 (11%) IBDU. The incidence of EO-IBD increased by 0.6 per 100 000 per year (0.8-3.2 per 100 000 per year), with a significant increase in UC by 0.06 per 100 000 per year (P=.02). Males with CD had more upper GI disease (L4a; 48% vs 21%; P=.007), more extensive disease distribution (L3±L4; 31% vs 11%; P=.05) and more severe disease activity at presentation (52% vs 31%; P=.05) than females. Fewer patients with early onset than later onset Crohn's disease had ileocolonic disease (L3; 10% vs 20%; P<.001). More relapses were observed in the first year post-diagnosis in early onset than later onset IBD (1.02 vs 0.5 mean relapses; P<.001).

CONCLUSIONS

EO-IBD is increasing in incidence. Males have more extensive and severe disease phenotypes, and younger patients have higher relapse rates than older children. Further research to explain these findings is warranted.

Rapid onset dystonia-parkinsonism in a 14-year-old girl

A painful dystonia of rapid onset and associated parkinsonian features is described in a girl aged 14 years. The condition is refractory to treatment and has led to severe neurological disability. Her father had presented with a similar picture.

Polymorphism in the epidermal growth factor gene is associated with birthweight in Sinhalese and white Western Europeans

Birthweight predicts health later in life and is influenced by inherited factors. We investigated the association of the c.61G > A, and c.2566G > A polymorphisms in the epidermal growth factor (EGF) gene [GenBank NM_001963] with birthweight in three groups of healthy pregnant women, and in women with pregnancies affected by fetal growth restriction (FGR). Subjects comprised 171 Sinhalese women with normal pregnancies (Group A), 64 white Western European women with normal pregnancies (Group B), 101 white Western European women with normal pregnancies and their babies (Group C) and 107 women with pregnancies affected by FGR, their partners and their babies (Group D). Maternal EGF genotypes were associated with birthweight of healthy babies of women in Groups A (P = 0.03), B (P = 0.001) and C (P = 0.01). The association persisted following adjustment for confounding by gestational age, sex, maternal weight, parity and smoking habit. The trend from heaviest to lightest birthweights in all these groups was c.61AA > c.61GA > c.61GG and c.2566GG > c.2566GA > c.2566AA. The EGF haplotype associated with lower birthweight (c.61G, c.2566A) was transmitted at increased frequency from heterozygous parents to babies affected by FGR in Group D (P = 0.02). These findings support the hypothesis that growth factors expressed by the feto-maternal unit affect birthweight, and implicates polymorphism in the EGF gene in the aetiology of birthweight variability.

Fabrication of oligonucleotide and protein arrays on rigid and flexible substrates coated with reactive polymer multilayers

We report a top-down approach to the fabrication of oligonucleotide and protein arrays on surfaces coated with ultrathin, amine-reactive polymer multilayers fabricated by the covalent "layer-by-layer" (LbL) assembly of polyethyleneimine (PEI) and the amine-reactive, azlactone-functionalized polymer poly(2-vinyl-4,4-dimethylazlactone) (PVDMA). Manual spotting of amine-terminated oligonucleotide probe sequences on planar glass slides coated with PEI/PVDMA multilayers (~35 nm thick) yielded arrays of immobilized probes that hybridized fluorescently labeled complementary sequences with high signal intensities, high signal-to-noise ratios, and high sequence specificity. Treatment of residual azlactone functionality with the nonfouling small-molecule amine d-glucamine resulted in regions between the features of these arrays that resisted adsorption of protein and permitted hybridization in complex media containing up to 10 mg/mL protein. The residual azlactone groups in these films were also exploited to immobilize proteins on film-coated surfaces and fabricate functional arrays of proteins and enzymes. The ability to deposit PEI/PVDMA multilayers on substrates of arbitrary size, shape, and composition permitted the fabrication of arrays of oligonucleotides on the surfaces of multilayer-coated sheets of poly(ethylene terephthalate) and heat-shrinkable polymer film. Arrays fabricated on these flexible plastic substrates can be bent, cut, resized, and manipulated physically in ways that are difficult using more conventional rigid substrates. This approach could thus contribute to the development of new assay formats and new applications of biomolecule arrays. The methods described here are straightforward to implement, do not require access to specialized equipment, and should also be compatible with automated liquid-handling methods used to fabricate higher-density arrays of oligonucleotides and proteins on more traditional surfaces.

Cyclical vomiting syndrome in children: a prospective study

BACKGROUND

Cyclical vomiting syndrome (CVS) is a disorder that affects all ages and is characterized by episodes of severe nausea and vomiting with symptom-free intervals between episodes. The incidence in children is 3.15/100 000 children per year. Our objective was to evaluate the natural history of CVS and examine factors that predict symptom resolution.

METHODS

Thirty newly diagnosed children (mean 9.15 years, SD 3.31 range 3.5-15.7) were enrolled. All children had a follow-up interview at 3 months, 27/30 at 6 months, and 22/30 at 9 months.

KEY RESULTS

Following diagnosis of CVS, only 5/22(22.7%) children had no further episodes of vomiting at 9 months, whereas 17/22 (77.3%) continued to vomit. In the year prior to diagnosis, 15/30 (50%) children were admitted to hospital. Of the 22 children with follow-up for 9 months, only one child required hospital admission. Children who continued to vomit had higher internalizing scores on CBCL compared with those who stopped vomiting (P = NS). The Pediatric Quality-of-Life Score suggested those who continued to vomit had a poorer quality of life at diagnosis compared with those who stopped vomiting (P < 0.05).

CONCLUSIONS & INFERENCES

Making a positive diagnosis of CVS and providing families with information is very important in the management of CVS. Although 75% of children reported regular episodes of vomiting 9 months after diagnosis, there was a significant reduction in the frequency and severity of symptoms in addition to a marked reduction in the use of medical services.

In situ Synthesis of Oligonucleotide Arrays on Surfaces Coated with Crosslinked Polymer Multilayers

We report an approach to the in situ synthesis of oligonucleotide arrays on surfaces coated with crosslinked polymer multilayers. Our approach makes use of methods for the 'reactive' layer-by-layer assembly of thin, amine-reactive multilayers using branched polyethyleneimine (PEI) and the azlactone-functionalized polymer poly(2-vinyl-4,4'-dimethylazlactone) (PVDMA). Post-fabrication treatment of film-coated glass substrates with d-glucamine or 4-amino-1-butanol yielded hydroxyl-functionalized films suitable for the Maskless Array Synthesis (MAS) of oligonucleotide arrays. Glucamine-functionalized films yielded arrays of oligonucleotides with fluorescence intensities and signal-to-noise ratios (after hybridization with fluorescently labeled complementary strands) comparable to those of arrays fabricated on conventional silanized glass substrates. These arrays could be exposed to multiple hybridization-dehybridization cycles with only moderate loss of hybridization density. The versatility of the layer-by-layer approach also permitted synthesis directly on thin sheets of film-coated poly(ethylene terephthalate) (PET) to yield flexible oligonucleotide arrays that could be readily manipulated (e.g., bent) and cut into smaller arrays. To our knowledge, this work presents the first use of polymer multilayers as a substrate for the multi-step synthesis of complex molecules. Our results demonstrate that these films are robust and able to withstand the ~450 individual chemical processing steps associated with MAS (as well as manipulations required to hybridize, image, and dehybridize the arrays) without large-scale cracking, peeling, or delamination of the thin films. The combination of layer-by-layer assembly and MAS provides a means of fabricating functional oligonucleotide arrays on a range of different materials and substrates. This approach may also prove useful for the fabrication of supports for the solid-phase synthesis and screening of other macromolecular or small-molecule agents.

[Motor activity and subjective findings in depressive patients]

Intensity of symptoms including mood and psychomotor activity has been shown to vary according to the time of the day in a group of depressed patients. This pattern represents one diagnostic criterion for the melancholic type of depression. The variation of intensity is experienced by the patient and can be observed as a behavioral symptom. However, the relation of circadian alterations in psychomotor activity and depressed mood remains unclear. Therefore, spontaneous motor activity and experienced intensity of symptoms were measured in 21 depressed patients who showed daily variations of subjective symptoms. Patients felt significantly less active, awake, and more depressed in the morning compared to the evening. However, corresponding activity levels, which were measured by actigraphy, appeared significantly higher in the morning compared to the evening. Increased motor activity could represent the observable behavioral equivalent of self-experienced psychomotor retardation and depressed mood.

Improved fruiting of Coprinus atramentarius using cold-shock treatment during growth

Coprinus atramentarius was grown on two commercial composts at a constant 20°C or with a cold shock (25°C→20°C) after 10 days. Cold shock was required for it to form fruiting bodies.

The technique of gait analysis using a Coda-3 motion analysis system

Gait analysis using Code-3 provides information which allows individual gait to be characterised with little interference to the patient. It is an ideal method for analysing gait in patients with cerebral palsy. Because of the ease with which this information is now available using Coda-3, gait analysis can now be performed on all ambulant patients in whom surgery is contemplated.