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The temporal dynamics of the neural activity that implements the dimensions valence and arousal during processing of emotional stimuli were studied in two multi-channel ERP experiments that used visually presented emotional words (experiment 1) and emotional pictures (experiment 2) as stimulus material. Thirty-two healthy subjects participated (mean age 26.8 +/- 6.4 years, 24 women). The stimuli in both experiments were selected on the basis of verbal reports in such a way that we were able to map the temporal dynamics of one dimension while controlling for the other one. Words (pictures) were centrally presented for 450 (600) ms with interstimulus intervals of 1,550 (1,400) ms. ERP microstate analysis of the entire epochs of stimulus presentations parsed the data into sequential steps of information processing. The results revealed that in several microstates of both experiments, processing of pleasant and unpleasant valence (experiment 1, microstate #3: 118-162 ms, #6: 218-238 ms, #7: 238-266 ms, #8: 266-294 ms; experiment 2, microstate #5: 142-178 ms, #6: 178-226 ms, #7: 226-246 ms, #9: 262-302 ms, #10: 302-330 ms) as well as of low and high arousal (experiment 1, microstate #8: 266-294 ms, #9: 294-346 ms; experiment 2, microstate #10: 302-330 ms, #15: 562-600 ms) involved different neural assemblies. The results revealed also that in both experiments, information about valence was extracted before information about arousal. The last microstate of valence extraction was identical with the first microstate of arousal extraction.

Brain electric mechanisms of temporary, functional binding between brain regions are studied using computation of scalp EEG coherence and phase locking, sensitive to time differences of few milliseconds. However, such results if computed from scalp data are ambiguous since electric sources are spatially oriented. Non-ambiguous results can be obtained using calculated time series of strength of intracerebral model sources. This is illustrated applying LORETA modeling to EEG during resting and meditation. During meditation, time series of LORETA model sources revealed a tendency to decreased left-right intracerebral coherence in the delta band, and to increased anterior-posterior intracerebral coherence in the theta band. An alternate conceptualization of functional binding is based on the observation that brain electric activity is discontinuous, i.e., that it occurs in chunks of up to about 100 ms duration that are detectable as quasi-stable scalp field configurations of brain electric activity, called microstates. Their functional significance is illustrated in spontaneous and event-related paradigms, where microstates associated with imagery- versus abstract-type mentation, or while reading positive versus negative emotion words showed clearly different regions of cortical activation in LORETA tomography. These data support the concept that complete brain functions of higher order such as a momentary thought might be incorporated in temporal chunks of processing in the range of tens to about 100 ms as quasi-stable brain states; during these time windows, subprocesses would be accepted as members of the ongoing chunk of processing.

Objective: In young, first-episode, never-treated schizophrenics compared with controls, (a) generally shorter durations of EEG microstates were reported (Koukkou et al., Brain Topogr 6 (1994) 251; Kinoshita et al., Psychiatry Res Neuroimaging 83 (1998) 58), and (b) specifically, shorter duration of a particular class of microstates (Koenig et al., Eur Arch Psychiatry Clin Neurosci 249 (1999) 205). We now examined whether older, chronic schizophrenic patients with positive symptomatology also show these characteristics. Methods: Multichannel resting EEG (62.2 s/subject) from two subject groups, 14 patients (36.1±10.2 years old) and 13 controls (35.1±8.2 years old), all males, was analyzed into microstates using a global approach for microstate analysis that clustered the microstates into 4 classes (Koenig et al., 1999). Results: (a) Hypothesis testing of general microstate shortening supported a trend (P=0.064). (b) Two-way repeated measure ANOVA (two subject groups×4 microstate classes) showed a significant group effect for microstate duration. Posthoc tests revealed that a microstate class with brain electric field orientation from left central to right central-posterior had significantly shorter microstates in patients than controls (68.5 vs. 76.1 ms, P=0.034). Conclusions: The results were in line with the results from young, never-treated, productive patients, thus suggesting that in schizophrenic information processing, one class of mental operations might intermittently cause deviant mental constructs because of premature termination of processing.

An abnormal facilitation of the spreading activation within semantic networks is thought to under-lie schizophrenics' remote associations and referential ideas. In normal subjects, elevated magical ideation (MI) has also been associated with a style of thinking similar to that of schizotypal subjects. We thus wondered whether normal subjects with a higher MI score would judge "loose associations" as being more closely related than do subjects with a lower MI score. In two experiments, we investigated whether judgments of the semantic distance between stimulus words varied as a function of MI. In the first experiment, random word pairs of two word classes, animals and fruits, were presented. Subjects had to judge the semantic distance between word pairs. In the second experiment, sets of three words were presented, consisting of a pair of indirectly related, or unrelated nouns plus a third noun. Subjects had to judge the semantic distance of the third noun to the word pair The results of both experiments showed that higher MI subjects considered unrelated words as more closely associated than did lower MI subjects. We conjecture that for normal subjects high on MI "loose associations" may not be loose after all. We also note that the tendency to link uncommon, nonobvious, percepts may not only be the basis of paranormal and paranoid ideas of reference, but also a prerequisite of creative thinking.

Multichannel EEG of an advanced meditator was recorded during four different, repeated meditations. Locations of intracerebral source gravity centers as well as Low Resolution Electromagnetic Tomography (LORETA) functional images of the EEG 'gamma' (35-44 Hz) frequency band activity differed significantly between meditations. Thus, during volitionally self-initiated, altered states of consciousness that were associated with different subjective meditation states, different brain neuronal populations were active. The brain areas predominantly involved during the self-induced meditation states aiming at visualization (right posterior) and verbalization (left central) agreed with known brain functional neuroanatomy. The brain areas involved in the self-induced, meditational dissolution and reconstitution of the experience of the self (right fronto-temporal) are discussed in the context of neural substrates implicated in normal self-representation and reality testing, as well as in depersonalization disorders and detachment from self after brain lesions.

Delleman syndrome is a rare disorder characterised by orbital cysts, micro/anophthalmia, malformations of the central nervous system, focal aplasia cutis, and multiple skin appendages (oculocerebrocutaneous syndrome). Although cutaneous findings provide the main clues for the diagnosis, the syndrome has received little attention in the dermatological literature. A new case of oculocerebrocutaneous syndrome with predominant and typical cutaneous involvement is reported.

We report a case of Henoch-Schönlein syndrome associated with human Parvovirus B19 primary infection. The patient, a 27-year-old Filipino woman, presented with an erythemato-papular-purpuric eruption localized to the lower limbs. General symptoms and signs included fever, hypotension, nausea, vomiting, abdominal pain, inguinal lymphadenopathy and polyarthralgia. Laboratory examinations showed leukocytosis, increase in total serum IgA, proteinuria and haematuria. Circulating IgA immune complexes were also present. The ELISA test for anti-human Parvovirus B19 IgM was positive. Histopathological examination revealed a leukocytoclastic vasculitis. This case confirms that also in adult patients, Henoch-Schönlein syndrome may be associated with human Parvovirus B19 infection.

An STM study of the morphologies generated by 1 keV Ar + sputtering in the 180–500 K temperature range is presented. It is shown that the sputtering temperature, T s , can be used to tune the final surface structure. At low temperatures, the surface is characterized by a random distribution of vacancy islands. When T s is increased, square-shaped vacancy islands with straight edges oriented along the principal crystallographic directions are observed. Depth, periodicity and dimension grow as a function of the substrate temperature until, for T s ≥440 K, an almost flat surface, resulting from a layer-by-layer removal, appears. A simple model, based on the microscopic surface diffusion processes, is also presented in which the importance of vacancy mobility is strongly stressed.

An optical low-coherence reflectometer is presented that uses a fiber Michelson interferometer with a rotating cube to generate rapid depth scans at a high repetition rate. A folded optical path geometry allows the reference arm to scale up the scan range, scan speed, and scan repetitiveness. Thickness measurements with a repetitiveness of 384 Hz and a longitudinal scanning speed of 21 m/s in air over a range of ∼3 mm are demonstrated.

Localized fibroma represents a rare entity arising from the pleura. Currently its histogenesis and clinical behaviour are still controversial. A case of a 64-year-old male is here presented; clinical and histopathological features are then discussed on the basis of a review of the Literature. At present, an en-bloc resection of the tumor, including wide margins of the surrounding lung tissue, seems to be the most appropriate surgical choice.

In excimer-laser photorefractive keratectomy (PRK) the depth of the stromal tissue ablation is calculated from calibration and empirical data but is not actually measured, since a noncontact high-precision instrument for the measurement of the actual ablation has not been available. With a newly developed method for optical pachymetry we studied the depth of corneal ablations performed with an excimer laser. The excimer laser (Schwind Keratom) was calibrated according to the manufacturers' instructions. On freshly enucleated pig eyes, planokeratectomies with a diameter of 5 mm and a planned depth of 20, 40, 80, 160, and 320 microns were performed. With a newly developed high-precision, high-speed reflectometer the corneal thickness was measured immediately before and after the keratectomy. All ablations were deeper than expected. For a planned keratectomy of 20 microns we found a mean ablation depth of 29 microns; for 40 microns, a mean depth of 51 microns; for 80 microns, a mean depth of 100 microns; for 160 microns, a mean depth of 200 microns; and for 320 microns, a mean depth of 396 microns. The differences between mean and maximal ablation values were 58.6% at the 20-micron setting, 40.9% at the 40-micron setting, 20.1% at the 80-micron setting, 11.5% at the 160-micron and 9.8% at the 320-micron setting. Ablation rates showed the highest degree of variation in the 20-micron ablation group. Absolute variations in the ablation depth increased with ablation depth. In photorefractive procedures the volume of the tissue ablated is calculated from the instrument calibration but is not actually measured. Although the greater than expected ablation depths may in part be explained by differences between human and porcine tissue, the high degree of variability in the laser ablations may have other causes. We suggest that variations in the postoperative refractive results of PRK, which are currently attributed to variations in corneal would healing, may in part be due to variations in ablation depth.

Xanthoma disseminatum (XD) is a rare mucocutaneous xanthoma nowadays classified as a benign non-Langerhans cell histiocytosis.We studied 7 cases of XD with a long follow-up and reviewed the literature in order to compare and discuss previous reports.We studied clinical manifestations, course, histopathologic, ultrastructural and immunohistochemical findings of 7 cases of XD followed for 1-20 years.We report our findings and compare our cases with those described in the literature.XD and Langerhans cell histiocytosis were distinguished by clinical differences, as well as ultrastructural and immunohistochemical methods. Three clinical patterns of XD appeared to emerge in our group of patients and in the cases reviewed from the literature.

Foot revascularization by popliteal-to-distal by-pass is a well documented procedure for limb salvage in diabetic patients. The authors report their experience with a consecutive series of 5 ischemic feet [transcutaneous oxygen (PtO2): 6 +/- 5.6 mmHg] due to extensive tibial artery occlusive disease beginning at the popliteal artery trifurcation. Limb salvage was achieved by popliteal-to-anterior tibial bypass (1 case) and popliteal-to-dorsalis pedis artery by-pass with autogenous inverted saphenous vein. No operative death was observed. At follow-up (range 3-34 months) one patient died at 3 months after surgery because of an intestinal bleeding. All 4 remaining by-passes are well functioning [PtcO2 46 +/- 11.2 mmHg) and all patients have resumed their normal walking distance. This preliminary experience, and a review of the literature, confirm the validity of the popliteal-to-distal by-pass and the need for more aggressive vascular surgical attitude to treat the ischemic diabetic foot.

Two cases of bleeding gastric angiodysplasia treated with a different approach, on the basis of the endoscopic features, are reported. Arteriovenous malformations may arise from any site of the digestive tract: gastric angiodysplasia represents one of the less frequent localizations, causing 2-5% of upper gastrointestinal bleeding. Several diagnostic tools are currently available and the choice of the most appropriate therapeutic strategy depends on many features: site and number of the lesions, patient's hemodynamic conditions, endoscopic skill. Surgery is preferred only when multiple and disseminated lesions within the gastric wall occur or when endoscopic approach fails.

A challenging question in the fields of neuroscience and addiction research is why some individuals are more vulnerable than others to addictive disorders. Pharmacogenetic studies investigating how genetic variation leads to differential drug response offer a way to unravel this mystery.In recent years, impulse control disorders, in particular pathological gambling, have been described in Parkinson's patients; these problems are most likely associated with dopaminergic treatment. Interestingly, only a subgroup of Parkinson's patients develops pathological gambling, raising the question whether there might be an interaction between genetic predisposition and dopaminergic drug administration. By applying a pharmacogenetic approach in 200 healthy subjects, we observed a differential effect of dopaminergic stimulation using 300 mg of L-DOPA on gambling behaviour, depending on variation in the dopamine D4 receptor gene. Carriers of the 7 repeats allele of the DRD4 exon III variable number tandem repeat polymorphism show an increased propensity to gamble after dopamine modulation. These findings may have implications for the dopaminergic treatment of Parkinson's disease patients by offering a genotype approach for determining individual susceptibilities for pathological gambling. They may also afford insights into the vulnerability mechanisms underlying addictive behaviour.

The Authors report a case of eosinophilic cellulitis (Wells' syndrome). The patient was a 61 year old woman, diabetic, with a cardio-respiratory insufficiency and a maniaco-depressive psycosis. She presented, on the upper arms and trunk, a cutaneous eruption of erythematous-urticarial plaques, that histopathologically were characterized by a dermic leukocyte population, with a prevalence of eosinophils, distributed in the perivascular site. Laboratory tests revealed eosinophilia and circulating immune complexes. The etiopathogenesis of the disease is discussed as is the possible role of immune complexes in eosinophilic cellulitis.

We report the case of a patient who presented a psoriasiform dermatitis after 8 months of atenolol therapy. Regression of the lesions was obtained after suspension of therapy. To our knowledge, few reports of psoriasiform dermatitis induced by atenolol are present in the literature. The Authors briefly discuss the pathogenesis of this drug induced disease.

Benign tumour originating from the ceruminous glands of the external auditory meatus are quite rare and present similar histological features to sweat gland tumours elsewhere. The paper reports the case of a nodule in the external auditory meatus diagnosed as a myoepitheliomatous-type hidradenoma . Three histological forms of benign ceruminous gland tumours are recognised: the myoepitheliomatous, cribriform and mixed salivary type. Currently, the term hidradenoma of the external ear is preferred.

This study investigates the precision and intraindividual variability of a clinical optical pachometer based on low-coherence reflectometry, which was used to measure the central thickness of a human cornea in vivo. The instrument, attached to a slit lamp, is a single mode fiber optic based Michelson interferometer with a high repetition rate as previously described. The same operator performed ten sets of measurements on the same subject, each consisting of 20 consecutive scans, on each day for three consecutive days. By computing the means from every scan series, the thickness of the central cornea with optical pachometry was found to be 519.6±1.2 (range 518-521) μm on day 1, 519.9±0.9 (range 519-521) μm on day 2, and 523.8±0.6 (range 523-525) μm on day 3. The thickness values on day 3, where the subject suffered from a cold without clinical ocular involvement, were different from the two previous days (plt;0.001, one way analysis of variance). Optical low-coherence reflectometry measurements of corneal thickness can be performed with high precision of about 1 μm and a high intra- and intersession reproducibility. © 1999 Society of Photo-Optical Instrumentation Engineers.

An optical low-coherence reflectometer is used for rapid noncontact measurements of the human corneal thickness in vivo. Thickness measurements on ten volunteers show a standard deviation of 3.4 μm. The experiments reveal that the optical reflectometer benefits from a 2.5 fold enhancement of the measurement precision and a 2.8 fold reduction in measurement time compared to a standard clinical ultrasonic pachometer. © 1998 Society of Photo-Optical Instrumentation Engineers.

A constant high-speed optical low-coherence reflectometer is presented. The use of both the reference and sample arms as delay lines results in highly linear optical path length changes. Scan speeds of up to 96 m/s are maintained over a range of typically 100 mm with a speed variation of only 0.1%.

We present a simple inverse method for finding travelling wave solutions of the one-dimensional reaction-diffusion (Fisher-Kolmogorv) equation for a restricted class of functions. We illustrate the method by some explicit, stable solutions in closed form.

After an accident in a chemical plant in Seveso, Italy, on July 10, 1976, 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) spread over a populated area. The event was exceptional because children were also affected and because the contamination took place not only through direct exposure but also through inhalation and the ingestion of contaminated foods, especially fruits and vegetables. This paper illustrates the early dermatologic lesions, the late acneic (chloracne) lesions, and their evolution during a 10-year period. Peculiar cutaneous findings, histologic data, and a comparison with previously reported similar accidents are also included.

Skin metastasis of digestive tumors is rarely encountered. In this paper the Authors describe a 60 years old patient who developed a submental skin metastasis from esophageal adenocarcinoma. A short literature review this unusual pathological event is also given.

An optical low-coherence reflectometer is actuated with an air bearing turbine to show the feasibility of scanning at rates lying typically one order of magnitude above previously reported high-speed scanning systems. The rotation frequency of the air turbine of 427 000 rpm leads to a repetition rate of longitudinal scans of 28.6 kHz. Coherent signals are detected over a distance of 2 mm at a longitudinal scan speed of 175 m/s.

We report, to our knowledge, the fastest longitudinal scans in optical low-coherence reflectometry published in literature. The use of a rotating glass cube as an optical path length variator results in a longitudinal scan speed of 42 m/s at a longitudinal scan repetition rate of 1240 Hz. The high-speed reflectometer is operated at the shot-noise limit corresponding to a sensitivity of -78 dB. The scalability of the scanning method with respect to scan speed, scan repetitiveness and scan length is demonstrated by the use of differently sized glass cubes.

A robust delay line comprising a rotated polygon mirror and a fixed glass parallelepiped is incorporated in an optical low-coherence reflectometer. A high degree of scalability of scan repetitiveness and scan range is obtained by producing the scan rate and scan range by means of a moving and a fixed element. The reflectometer is operated at a scan repetition rate and a scan speed of 2.58 kHz and 37 m/s, respectively.

AIMS: The histological features used in the diagnosis of melanoma may be present in benign naevi, but quantitative data are not available. The aim of this study was to establish the real prevalence of such features in naevi. METHODS: Ten dermatopathologists, from nine Italian institutions, studied a series of naevi. Eleven histological parameters currently used in melanoma diagnosis were analysed: asymmetry, poor circumscription, predominance of single melanocytes, irregular confluent nests, suprabasal melanocytes, hair follicle involvement, absence of maturation, cytological atypia, dermal lymphocytic infiltrate, mitoses, and necrosis. RESULTS: Ninety one naevi were examined: 22 junctional, 59 compound, and 10 intradermal. None of the studied parameters was seen in 22 of the benign naevi studied. One or more investigated features were found in 69 naevi. Poor circumscription was found in 49 cases, single melanocytic predominating in 42, asymmetry in 41, irregular confluent nests in 16, cytological atypia in 14, suprabasal melanocytes in seven, and hair follicle involvement in seven; absence of maturation, mitoses and necrosis were not found. CONCLUSIONS: The histological features used for the histological diagnosis of melanoma are often present in benign melanocytic naevi. This suggests a critical, non-mechanical use of them in melanoma diagnosis.