Medical comorbidities in bipolar disorder (BIPCOM): clinical validation of risk factors and biomarkers to improve prevention and treatment. Study protocol

BACKGROUND

BIPCOM aims to (1) identify medical comorbidities in people with bipolar disorder (BD); (2) examine risk factors and clinical profiles of Medical Comorbidities (MC) in this clinical group, with a special focus on Metabolic Syndrome (MetS); (3) develop a Clinical Support Tool (CST) for the personalized management of BD and medical comorbidities.

METHODS

The BIPCOM project aims to investigate MC, specifically MetS, in individuals with BD using various approaches. Initially, prevalence rates, characteristics, genetic and non-genetic risk factors, and the natural progression of MetS among individuals with BD will be assessed by analysing Nordic registers, biobanks, and existing patient datasets from 11 European recruiting centres across 5 countries. Subsequently, a clinical study involving 400 participants from these sites will be conducted to examine the clinical profiles and incidence of specific MetS risk factors over 1 year. Baseline assessments, 1-year follow-ups, biomarker analyses, and physical activity measurements with wearable biosensors, and focus groups will be performed. Using this comprehensive data, a CST will be developed to enhance the prevention, early detection, and personalized treatment of MC in BD, by incorporating clinical, biological, sex and genetic information. This protocol will highlight the study's methodology.

DISCUSSION

BIPCOM's data collection will pave the way for tailored treatment and prevention approaches for individuals with BD. This approach has the potential to generate significant healthcare savings by preventing complications, hospitalizations, and emergency visits related to comorbidities and cardiovascular risks in BD. BIPCOM's data collection will enhance BD patient care through personalized strategies, resulting in improved quality of life and reduced costly interventions. The findings of the study will contribute to a better understanding of the relationship between medical comorbidities and BD, enabling accurate prediction and effective management of MetS and cardiovascular diseases.

TRIAL REGISTRATION

ISRCTN68010602 at https://www.isrctn.com/ISRCTN68010602 . Registration date: 18/04/2023.

Enhanced recovery protocol in esophagectomy, is it really worth it? A cost analysis related to team experience and protocol compliance

Application of enhanced recovery protocols (ERP) in esophageal surgery seems to lead an advantage in terms of length of hospital staying and outcomes, but only few data exist on its cost effectiveness. Previous literature analyzed pre- and post-ERP groups, finding a cost reduction with the introduction of the pathway. We aimed to study the influence on costs of accumulating experience and compliance in an ERP group. Seventy-one patients have been treated at our institution from January 2014 to June 2017 with our ERP for Ivor-Lewis esophagectomy. Direct costs were divided into subcategories and were analyzed as a function of calendar year and compliance. Factor affecting costs were searched. Univariable analysis highlighted a significant reduction in costs over time. Increase in compliance led to a progressive cost reduction for each ERP item completed (€14 852-€11 045). While age was not found to significantly influence the cost (p = 0.341), complications seemed to nullify the effect of experience: the median was €11 507 in uncomplicated patients, and increased to €13 791 in Clavien-Dindo 3-4 (CD3-4) patients. Compliance and CD3-4 remained significant also in multivariable analysis, accomplished by quantile regression, while year of surgery lost its significance. Our results evidence how accumulating experience in ERP led to a cost reduction over time, which was mainly mediated by an increase in compliance. Indeed, compliance was the main factor in reducing ERP cost while CD3-4 complications were the most important factor in cost increasing, nullifying the benefit of compliance.

Rhodium nanoparticles stabilized by ferrocenyl-phosphine ligands: synthesis and catalytic styrene hydrogenation

A series of ferrocenylphosphine-stabilized rhodium nanoparticles has been prepared in one pot from the organometallic [Rh(η3-C3H5)3] precursor. This complex has been decomposed by hydrogen treatment (3 bar) in dichloromethane in the presence of five different ferrocene-based phosphine ligands. Very small rhodium nanoparticles in the size range of 1.1-1.7 nm have been obtained. These nanoparticles have shown activity in a model catalytic reaction, namely the hydrogenation of styrene. These results evidence that the metal surface is not blocked despite the steric bulk of the stabilizing ligands. Moreover, certain selectivity has been observed depending on the ligand employed. To the best of our knowledge, such a type of compound has not yet been used for stabilizing metal nanoparticles and our findings highlight the interest to do so.

Crosstalk Reduction in Epimysial EMG Recordings from Transhumeral Amputees with Principal Component Analysis

Electromyographic (EMG) recordings of muscle activity using monopolar electrodes suffer from poor spatial resolution due to the crosstalk from neighbouring muscles. This effect has mainly been studied on surface EMG recordings. Here, we use Principal Component Analysis (PCA) to reduce the crosstalk in recordings from unipolar epimysial electrodes implanted in three transhumeral amputees. We show that the PCA-transformed signals have, on average, a better signal-tonoise ratio than the original unipolar recordings. Preliminary investigations show that this transformation is stable over long periods of time. If the latter is confirmed, our results show that the combination of PCA with unipolar electrodes allows for a higher number of muscles to be targeted in an implant (compared with bipolar electrodes), thus facilitating 1-to-1 proportional control of prosthetic hands.

Daytime Circulating Melatonin Levels in Smokers

Aims and background

Melatonin secretion is required to be a potential inhibitor of the development and growth of tumors, and cigarette smoking is a well established risk factor for cancer at various sites.

Methods

Circulating melatonin levels of 20 smokers and 20 non smokers (controls), sampled at the same hour from awaking in order to obtain a comparable circadian synchronization, were compared.

Results

Our data showed higher melatonin circulating levels in smokers (17.44 ±1.8 pg/ml) than in nonsmokers (9.77 ± 1.4 pg/ml).

Conclusions

The causes, mechanism and meaning of this phenomenon are still unknown. The most actractive hypothesis considers higher melatonin levels in smokers as an attempt to counterbalance cellular growth stimulus, a natural “brake” mechanism to restrain the proliferation of normally differentiated tissues: smoke is a prominent risk factor for several different tumors.

Superwellness Program: a cognitive-behavioral therapy-based group intervention to reduce weight gain in patients treated with antipsychotic drugs

Objective:

To assess the effectiveness of a cognitive-behavioral therapy-based intervention (Superwellness Program) on weight gain compared with a treatment-as-usual (TAU) approach in patients treated with antipsychotics, and to evaluate the relationship between body mass index (BMI) variation and clinical variables.

Method:

Eighty-five patients treated with antipsychotics were allocated across two groups, experimental (n=59) and control (n=26). The Superwellness Program (experimental group) consisted of 32 twice-weekly 1-hour sessions, conducted by a psychologist and a nutritionist/nurse, concurrently with moderate food intake and moderate physical activity plans. Sociodemographic, clinical, and biological variables were collected at baseline, at the end of intervention (16 weeks), and after 6 months.

Results:

BMI change from baseline differed significantly between the experimental and control groups, with a larger decrease in the experimental group (F = 5.5, p = 0.021). Duration of illness moderated the effect of treatment on BMI (p = 0.026). No significant (p = 0.499) effect of intervention during the follow-up period was found. Interestingly, the intervention indirectly induced a significant (p = 0.024) reduction in metabolic risk by reducing BMI.

Conclusion:

A cognitive-behavioral therapy-based intervention could be useful in reducing weight in a clinical population taking antipsychotics, with consequent benefit to physical and mental health.

Does cognitive remediation modify the use of psychiatric services and the patterns of care of patients with schizophrenia?

The use of inpatient and outpatient psychiatric services were assessed in the 12months before and after a cognitive remediation (CR) intervention or treatment as usual (TAU) in a sample of 84 patients with schizophrenia who previously underwent an effectiveness study of CR. A smaller number and shorter duration of hospitalizations in acute wards and a higher total number of outpatient and rehabilitative interventions, as well as a more constant, intensive and articulated rehabilitation in the 12months after the intervention were found in patients who received CR, compared with those who received TAU. CR may modify the use of psychiatric services and the patterns of care of patients with schizophrenia.

Multi-leveled objects: color as a case study

The paper presents color as a case study for the analysis of phenomena that pertain to several levels of reality and are typically framed by different sciences and disciplines. Color, in fact, is studied by physics, biology, phenomenology, and esthetics, among others. Our thesis is that color is a different entity for each level of reality, and that for this reason color generates different observables in the epistemologies of the different sciences. By analyzing color as a paradigmatic case of an entity naturally spreading over different levels of reality, the paper raises the question as to whether making explicit the usually implicit ontological assumptions embedded within the different observables exploited by the different sciences may eventually clarify some of the difficulties of developing a comprehensive theory of color.

Predictors of cognitive and functional improvement and normalization after cognitive remediation in patients with schizophrenia

OBJECTIVE

Although the efficacy of cognitive remediation interventions has been demonstrated in several experimental studies on schizophrenia, few studies have investigated the predictors of response to such interventions. We were interested in determining what factors contribute to a positive outcome after cognitive rehabilitation and whether different factors are associated with different degrees of improvement in cognitive and real-world functioning in individual patients after cognitive remediation.

METHODS

The study sample consisted of 56 patients with schizophrenia who had completed a 6-month cognitive remediation intervention and showed different cognitive and functional outcomes. Measures of cognitive and functional amelioration after cognitive remediation were analyzed in relation to patients' clinical, neuropsychological and functional variables at baseline using logistic regression analysis.

RESULTS

Lower antipsychotic intake at baseline predicted cognitive improvement, whereas lower antipsychotic intake, severity of specific symptoms, and higher neurocognitive functioning (particularly executive functions and verbal memory) at baseline were associated with cognitive normalization after remediation treatment. Functional improvement was predicted by lower patient age and type of cognitive remediation intervention, whereas functional normalization was related to lower baseline antipsychotic intake and, at a trend level, to higher executive functioning and type of cognitive remediation intervention.

CONCLUSION

Cognitive remediation could be more effective in younger, less disorganized, and cognitively less impaired patients, who take a smaller amount of antipsychotics. The predictive role of lower antipsychotic dosage on cognitive and functional outcome after remediation suggests either that patients with less severe illness could gain better advantage from cognitive remediation interventions or that high dose or complex antipsychotic therapy may limit the effectiveness of such interventions.

Pituitary gland metastasis from rectal cancer: report of a case and literature review

Pituitary metastases are unusual complications of malignancies. In about only 2% of patients they origin from colorectal cancer (CRC), with breast and lung as the most common primary tumors. Nevertheless, some authors reported a recent increase of the incidence of metastases in infrequent sites, such as brain or bone, arising from gastrointestinal cancers, probably due to the expanded treatment options and the resulting improved survival. Here, we report the case of a 54-year old woman diagnosed with lung metastases from rectal cancer, who, after several cycles of radio- and chemotherapy, presented symptoms and signs of pituitary disfunction (i.e. diabetes insipidus, hypothyroidism and diplopy). The diagnosis of pituitary metastasis from rectal cancer was histologically confirmed after surgery.

Interview-based assessment of cognition in schizophrenia: applicability of the Schizophrenia Cognition Rating Scale (SCoRS) in different phases of illness and settings of care

INTRODUCTION

The Schizophrenia Cognition Rating Scale (SCoRS), an interview-based assessment of cognition, has proved to be a valid measure of cognitive performance in patients with schizophrenia.

OBJECTIVE

The aims of this study were to analyze the validity of this scale in a naturalistic setting representative of the Italian system of psychiatric care, and to test whether the SCoRS could be appropriately used in different phases of illness and contexts of care.

METHODS

Eighty-six patients with schizophrenia (DSM-IV-TR criteria) (N = 59 clinically stabilized patients; N = 27 recently hospitalized patients) were administered the SCoRS. The reliability of SCoRS was assessed and global ratings were correlated with neurocognitive, clinical, and psychosocial functioning measures.

RESULTS

SCoRS inter-rater and test-retest reliability were high. In clinically stabilized patients, SCoRS global ratings were significantly correlated with composite scores of cognitive performance (global cognitive index: r = -0.570, P<0.001), symptoms (Positive and Negative Syndrome Scale (PANSS) total score: r = 0.602, P < 0.001), and psychosocial functioning (Global Assessment of Functioning (GAF): r = -0.532, P<0.001; Health of the Nation Outcome Scale (HoNOS): r = 0.433, P < 0.001). On the other hand, no such correlations were found in recently hospitalized patients. Correlations with neuropsychological and functional measures were less significant as the severity of the patients' symptoms, especially positive symptoms, increased.

CONCLUSION

The SCoRS is a valid measure of cognitive performance and is related to psychosocial functioning, especially in clinically stable patients with schizophrenia. The usefulness of the SCoRS in patients recently admitted to hospital for an acute phase of illness is uncertain.

Internet addiction disorder: prevalence in an Italian student population

BACKGROUND

Internet addiction is one of the latest forms of addiction that has attracted the attention of popular media and researchers in these last few years. Several authors think Internet addiction is a separate disorder that merits inclusion in DSM-V. There is considerable controversy about this opinion.

AIMS

The aim of this study was to assess the prevalence of Internet addiction in a representative sample of high school students attending secondary institutions in the district of Cremona and to assess any difference concerning variables such as gender, age, place of residence and kind of school attended.

METHODS

The Italian version of the Internet Addiction Test (IAT) has been administered to a sample of 2533 students from different kinds of school. The survey also required social and demographic data.

RESULTS

The majority of respondents were classified as normal users of the Internet (n = 2386, 94.19%), with 127 (5.01%) moderately addicted and 20 (0.79%) seriously addicted. Significant differences in gender and in kinds of school were found. No statistical differences were revealed in age and urban or rural conditions.

CONCLUSIONS

Our study has confirmed the general use of the Internet among youngest people, the emergence of Internet addiction and the male preponderance of this phenomenon.

Diene-Containing half-sandwich MoIII complexes as ethylene polymerization catalysts: experimental and theoretical studies

Seventeen-electron compounds of MoIII having the general formula [(eta5-C5R5)Mo(eta4-diene)X2] (R = H, Me: dieney = butadiene, isoprene, or 2,3-dimethylbutadiene: X= Cl, CH3) are a new class of ethylene polymerization catalysts. The polyethylene obtained shows a bimodal distribution, the major weight fraction being characterized by very long (M around 10(6)) and highly linear polymer chains. The newly prepared pentamethylcyclopentadienyl (Cp*) derivatives are more active than the cyclopentadienyl (Cp) derivatives, but much less active than previously investigated niobiumIII compounds having the same stoichiometry. On the other hand, the turnover frequency of the active site leading to the high molecular weight chains is at least 10 times greater than that obtained with the corresponding Nb catalyst. The reason for the low activity is explained by a difficult activation process that is attributed to the low polarity and high strength of the Mo-alkyl bond. This is confirmed by a Mulliken charge analysis of density functional theory (DFT) geometry-optimized [CpM(eta4-C4H6)(CH3)2] (M = Nb, Mo) and by the calculation of the heterolytic bond dissociation energies. DFT calculations have also been carried out on the ethylene insertion coordinate for the [CpM(eta4-C4H6)(CH3)]+ model of the presumed active site. The results indicate an equivalent activation barrier to insertion for the Nb and Mo systems. Differences in optimized geometries for the reaction intermediates are attributed to the presence of the extra electron for the Mo system. This electron opposes the formation of M-H-C agostic interactions, while it strengthens the back-bonding M-ethylene interaction, but otherwise plays no active role in the polymer chain propagation mechanism. According to the calculations, the chain propagation for the Mo system occurs entirely on the spin doublet surface, the minimum energy crossover point with the quartet surface lying at a higher energy than the transition state for insertion on the doublet surface.

Radical polymerization of styrene controlled by half-sandwich Mo(III)/Mo(IV) couples: all basic mechanisms are possible

Density functional calculations of bond dissociation energies (BDEs) have been used as a guide to the choice of metal system suitable for controlling styrene polymerization by either the stable free radical polymerization (SFRP) or the atom transfer radical polymerization (ATRP) mechanism. In accord with the theoretical prediction, CpMo(eta(4)-C(4)H(6))(CH(2)SiMe(3))(2), 2, is not capable of yielding SFRP of styrene. Still in accord with theoretical prediction, CpMo(eta(4)-C(4)H(6))Cl(2), 1, CpMo(PMe(3))(2)Cl(2), 3, and CpMo(dppe)Cl(2) (dppe = 1,2-bis(diphenylphosphino)ethane), 4, yield controlled styrene polymerization by the SFRP mechanism in the presence of 2,2'-azobisisobutyronitrile (AIBN). This arises from the generation of a putative Mo(IV) alkyl species from the AIBN-generated radical addition to the Mo(III) compound. The controlled nature of the polymerizations is indicated by linear M(n) progression with the conversion in all cases and moderate polydispersity indices (PDIs). Controlled polymerization of styrene is also given by compounds 3 and 4 in combination with alkyl bromides. These complexes then operate by the ATRP mechanism, again in accord with the theoretical predictions. Controlled character is revealed by linear increase of M(n) versus conversion, low PDIs, a stop-and-go experiment, and (1)H NMR and MALDI-TOF analyses of the polymer end groups. The same controlled polymerization is given by a "reverse" ATRP experiment, starting from AIBN and CpMo(PMe(3))(2)Cl(2)Br, 5. On the other hand, when compound 1 or 2 is used in combination with an alkyl bromide (as for an ATRP experiment), the isolated polystyrene shows by M(n), (1)H NMR, and MALDI-TOF analyses that catalytic chain transfer (CCT) radical polymerization takes place in this case. Kinetics simulations underscore the conditions regulating the radical polymerization mechanism and the living character of the polymerization. The complexes herein described are ineffective at controlling the polymerization of methyl methacrylate.

A Computational Study of Ethylene C−H Bond Activation by [Cp*Ir(PR3)]

It has previously been demonstrated that both [(C5Me5)Ir(PMe3)(CH=CH2)H] and [(C5Me5)Ir(PMe3)(H2C=CH2)] are formed when [(C5Me5)Ir(PMe3)] is thermolytically generated in the presence of ethylene. At higher temperatures, the vinyl hydride is converted to the eta2-ethylene adduct. Density functional theory has now been used to investigate this reaction, using the B3LYP functional, two types of basis sets (LanL2DZ and TZV*), and two models of the [(C5R5)Ir(PR3)] species (R=H and CH3). The study consists of full optimizations of local minima, first-order saddle points, and minimum energy crossing points (MECP). The experimental results are best accounted for by considering both singlet and triplet spin surfaces. The relative energies of singlet [(C5R5)Ir(PR3)(CH3)H], [(C5R5)Ir(PR3)(CH=CH2)H], and [(C5R5)Ir(PR3)(H2C=CH2)] are in good agreement with experiment, as is the calculated barrier for the conversion from the vinyl hydride to the eta2-alkene complex. However, the singlet surface alone fails to explain the experimentally observed product ratio, or the intermediate inferred from experimental isotope effect studies. Locating the MECP between singlet and triplet surfaces indicates that the thermolysis of the singlet alkyl hydride precursor directly forms triplet [(C5R5)Ir(PR3)]. The weak vanderWaals adduct of triplet [(C5R5)Ir(PR3)] and ethylene is proposed to be the key intermediate in the overall reaction. The interchanging of the available ethylene C-H bonds in this triplet sigma complex accounts for the observed kinetic isotope effects, and partitioning between alkene pi-complexation and C-H bond activation may also occur from this common intermediate. The possible role of steric factors and molecular dynamics are also discussed.

Synthesis of beta-P,N aminophosphines and coordination chemistry to Pd(II). X-ray structures of [PdCl2(Ph2PCH(Ph)NHPh-kappaP,kappaN)] and PdCl(eta3-C3H5)(Ph2PCH2CH(Ph)NHPh-kappaP)]

The reaction of the C=N bond in PhCH=NPh with the carbanionic species Ph2PCH2-, leading to the N-phenyl beta-aminophosphine Ph2PCH2CH(Ph)NHPh, L1, is described. This molecule reacts with different organic electrophiles to afford related compounds Ph2PCH2CH(Ph)NPhX (X = SiMe3, L2; COPh, L4), [Ph2MePCH2CH(Ph)NHPh]+(I-), L3, and [Ph2PCH2CH(Ph)N(Ph)CO]2, L5, containing two amido and two phosphino functions. The coordination properties of L1, L2, and L4 have been studied in palladium chemistry. The X-ray structure of [PdCl2(Ph2PCH2CH(Ph)NHPh-kappaP,kappaN)] shows the bidentate coordination mode for the L1 ligand with equatorial C(Ph)-N(Ph) phenyl groups. [PdCl2(Ph2PCH2CH(Ph)NHPh-kappaP,kappaN)] crystallizes at 298 K in the space group P2(1)/n with cell parameters a = 10.689(2) A, b = 21.345(3) A, c = 12.282(2) A, beta = 90.294(12) degrees, Z = 4, D(calcd) = 1.526. The reaction between 2 equiv of L1 and [PdCl(eta3-C3H5)]2 affords the [PdCl(eta3-C3H5)(Ph2PCH2CH(Ph)NHPh-kappaP)] complex in which an unexpected N-H.Cl intramolecular interaction has been observed by an X-ray diffraction analysis. [PdCl(eta3-C3H5)(Ph2PCH2CH(Ph)NHPh-kappaP)] crystallizes at 298 K in the monoclinic space group Cc with cell parameters a = 10.912(1) A, b = 17.194(2) A, c = 14.169(2) A, beta = 100.651(9) degrees, Z = 4, D(calcd) = 1.435. Neutral and cationic alkyl or allyl palladium chloride complexes containing L1 are also reported as well as a neutral allyl palladium chloride complex containing L4. Variable-temperature 31P[1H] NMR studies on the allyl complexes show that the eta3/eta1 allyl interconversion is enhanced by a positive charge and also by a N-H.Cl intramolecular interaction.

Eye movement abnormalities in myotonic dystrophy

We studied saccade and smooth pursuit eye movements in 31 patients suffering from myotonic dystrophy (MD). On the basis of mean value comparisons, saccades were slower and hypometric and smooth pursuit eye movements performed worse in MD patients than in controls. On an individual basis, saccade duration was prolonged in 67.7%, saccades were hypometric in 19.4%, saccade latency was delayed in 9.7%, and the smooth pursuit performance index was decreased in 9.7% of patients. Eye movement abnormalities did not correlate with those detectable by visual, brain-stem auditory and somatosensory evoked potentials. We attempted to classify eye movement abnormalities as myogenic or neurogenic on the basis of differences in combination of eye movement abnormalities and the occurrence of D5/D35 dissociation; the latter consists of a prolonged duration for large (35 degrees) but not for small (5 degrees) saccades. Since D5/D35 dissociation occurred in 26/33 multiple sclerosis patients with increased saccade duration, we considered it to be a neurogenic pattern attributable to a central nervous system (CNS) dysfunction. A prolonged duration without dissociation especially in combination with saccade hypometria, is interpreted as a myogenic pattern, although the lack of dissociation may also occur with CNS impairment in case of a marked increase in saccade duration. Accordingly we classified the oculomotor abnormalities detected as neurogenic in 11 MD patients and as myogenic in another 10, but in some subjects belonging to the second group concomitant CNS impairment is not to be excluded.

Schema theory for genetic programming with one-point crossover and point mutation

We review the main results obtained in the theory of schemata in genetic programming (GP), emphasizing their strengths and weaknesses. Then we propose a new, simpler definition of the concept of schema for GP, which is closer to the original concept of schema in genetic algorithms (GAs). Along with a new form of crossover, one-point crossover, and point mutation, this concept of schema has been used to derive an improved schema theorem for GP that describes the propagation of schemata from one generation to the next. We discuss this result and show that our schema theorem is the natural counterpart for GP of the schema theorem for GAs, to which it asymptotically converges.

Clinical aspects of fatigue in multiple sclerosis

We studied 100 multiple sclerosis outpatients in order to assess the frequency of fatigue and to detect its relationships with other clinical findings. Fatigue was quantified by fatigue severity scale (FSS; range 1-7); current clinical neurological status and disability level were respectively scored by Kurtzke's functional systems and expanded disability status scale (EDSS). FSS mean score was 4.12; fatigue was totally absent in 3% of the patients. Fatigue started before onset of the disease in 7 patients, at onset in 12 and within the first year in 7. Fatigue intensity and frequency were related to each other. FSS mean scores were significantly higher in the patients with fatigue worsened by heat (p < 0.01), with chronic progressive disease (p < 0.0001), with motor symptoms (p < 0.0001) and with EDSS > or = 3.5 (p < 0.0001). Multiple regression analysis showed a significant effect of EDSS on fatigue (p < 0.0001), not attributable to differences in duration of the disease.

An algorithm for real-time vessel enhancement and detection

In this paper we present an algorithm for the real-time enhancement and detection of blood vessels in medical images. The algorithm is based on a set of linear filters sensitive to vessels of different orientation and thickness. Such filters are obtained as linear combinations of properly shifted Gaussian kernels. The output of multiple oriented vessel-enhancing filters can be integrated to obtain images in which vessels are highly enhanced independently of their direction and thickness. To avoid spurious responses in the presence of step edges or to enhance the skeletons of vessels, the output of directional filters can be validated before integration. Skeleton detection and vessel segmentation can be performed via thresholding with hysteresis. Experimental results on synthetic images and real coronary arteriograms are reported.

Genetic design of optimum linear and nonlinear QRS detectors

This paper describes an approach to the design of optimum QRS detectors. We report on detectors including a linear or nonlinear polynomial filter, which enhances and rectifies the QRS complex, and a simple, adaptive maxima detector. The parameters of the filter and the detector, and the samples to be processed are selected by a genetic algorithm which minimizes the detection errors made on a set of reference ECG signals. Three different architectures and the experimental results achieved on the MIT-BIH Arrhythmia Database are described.

Recovery of the 3-D shape of the left ventricle from echocardiographic images

A computational method is reported which allows the fully automated recovery of the three-dimensional shape of the cardiac left ventricle from a reduced set of apical echo views. Two typically ill-posed problems have been faced: 1) the detection of the left ventricle contours in each view, and 2) the integration of the detected contour points (which form a sparse and partially inconsistent data set) into a single surface representation. The authors' solution to these problems is based on a careful integration of standard computer vision algorithms with neural networks. Boundary detection comprises three steps: edge detection, edge grouping, and edge classification. The first and second steps (which are typical early-vision tasks not involving specific domain-knowledge) have been performed through fast, well-established algorithms of computer vision. The higher level task of left ventricle-edge discrimination, which involves the exploitation of specific knowledge about the left ventricle silhouette, has been performed by feedforward neural networks. Following the most recent results in the field of computer vision, the first step in solving the problem of recovering the ventricle surface has been the adoption of a physically inspired model of it. Basically, the authors have modeled the left ventricle surface as a closed, thin, elastic surface and the data as a set of radial springs acting on it. The recovery process is equivalent to the settling of the surface-plus-springs system into a stable configuration of minimum potential energy. The finite element discretization of this model leads directly to an analog neural-network implementation. The efficiency of such an implementation has been remarkably enhanced through a learning algorithm which embeds specific knowledge about the shape of the left ventricle in the network. Experiments using clinical echographic sequences are described. Four apical views (each with a different rotation of the probe) have been acquired during a heartbeat from a set of seven normal subjects. These images have been utilized to set the various processing modules and test their capabilities.

[Epidemics of musculotendinous pathologies of the upper limbs (cumulative trauma disorders) in a group of assembly line workers]

The study was prompted by a report concerning a group of assembly line workers in a factory producing prams who had developed various muscular and tendinous disorders of the upper limbs that can be classified under the larger category of Cumulative Trauma Disorders (CTD). The study first concentrated on the working conditions with analysis of the main factors responsible for overloading of the upper limbs during work. This analysis revealed high frequency and repetitiveness of upper limb movements together with a marked inadequacy of the length and distribution of pauses. In a significant part of the operations the workers also performed movements in positions that over loaded the wrist and hand. A parallel clinical and instrumental study carried out in collaboration with specialists in orthopedics, brain surgery and neurophysiology on all 40 workers in the shop showed that 90% of the subjects suffered from a form of CTD of the upper limbs: in particular, 40% were affected with carpal tunnel syndrome (12.5% bilateral), and there were high prevalence of tenosynovitis (32% Trigger Finger, 17% De Quervain's syndrome) and epicondylitis (20% medial or lateral). The results of the study once again emphasize the need for greater attention of occupational health practitioners in Italy for muscular and tendinous disorders of the upper limbs due to repeated strain, which Italian law defines, albeit controversially, as occupational.

A neural network architecture for understanding discrete three-dimensional scenes in medical imaging

Magnetic resonance and computed tomography produce sets of tomograms which are termed discrete 3D scenes. Usually, discrete 3D scenes are analyzed in two dimensions by observing each tomogram on a screen so that the three-dimensional information contained in the scene can be recovered only partially and qualitatively. The three-dimensional reconstruction of the shape of biological structures from discrete 3D scenes would allow a complete and quantitative recovery of the available information, but this task has proved hard for conventional processing techniques. In this paper we present a system architecture based on neural networks for the fully automated segmentation and recognition of structures of interest in discrete 3D scenes. The system includes a retina and two main processing modules, an Attention-Focuser System and a Region-Finder System, which have been implemented by using feed-forward nets trained with the back-propagation algorithm. This architecture has been tested on computer-simulated structures and has been applied to the reconstruction of the spinal cord and the brain from sets of tomograms.

Dysgraphia and selective impairment of the graphemic buffer

We report the linguistic analysis of a case of pure dysgraphia whose features suggest a selective deficit of the graphemic buffer. We discuss the neuropsychological pattern in the light of theoretical models of the cognitive processes considered to underlie writing skills.

[Neurolinguistic analysis of a case of pure agraphia]

A patient with a pure acquired dysgraphia is reported. The pattern of the patient's performance is discussed in relation to current functional models of writing. The case may be interpreted by assuming a selective impairment to the graphemic buffer.

[The verbal fluency test for the diagnosis of dementia]

Two forms of verbal fluency test, phonological (FF) and semantic (FS) sets, have been administered to four groups of demented patients: 11 with Alzheimer-type dementia (DAT), 13 with multi-infarct dementia (MID), 8 with Parkinson-Dementia (P-D) and 11 with adult chronic hydrocephalus (ICA). Patients were matched for age, educational level and neuropsychological impairment pattern. Further, ten neurologically healty subjects were selected as control group. Control subjects result to be different from all other groups in both FF and FS; moreover, FF test results to be more impaired in ICA than in DAT. Furthermore, FF is more impaired than FS in P-D and ICA patients. On the basis of our results, verbal fluency tests might represent an useful instrument to differentiate demented subjects from non-demented ones and within demented groups to characterize the different neuropsychological pattern of the cortical and subcortical type of cognitive deterioration.