Model-based signal processing enables bidirectional inferring between local field potential and spikes evoked by noxious stimulation.

BACKGROUND: Recording spontaneous and evoked activities by means of unitary extracellular recordings and local field potential (LFP) are key understanding the mechanisms of neural coding. The LFP is one of the most popular and easy methods to measure the activity of a population of neurons. LFP is also a composite signal known to be difficult to interpret and model. There is a growing need to highlight the relationship between spiking activity and LFP. Here, we hypothesized that LFP could be inferred from spikes under evoked noxious conditions. METHOD: Recording was performed from the medullary dorsal horn (MDH) in deeply anesthetized rats. We detail a process to highlight the C-fiber (nociceptive) evoked activity, by removing the A-fiber evoked activity using a model-based approach. Then, we applied the convolution kernel theory and optimization algorithms to infer the C-fiber LFP from the single cell spikes. Finally, we used a probability density function and an optimization algorithm to infer the spikes distribution from the LFP. RESULTS: We successfully extracted C-fiber LFP in all data recordings. We observed that C-fibers spikes preceded the C-fiber LFP and were rather correlated to the LFP derivative. Finally, we inferred LFP from spikes with excellent correlation coefficient (r = 0.9) and reverse generated the spikes distribution from LFP with good correlation coefficients (r = 0.7) on spikes number. CONCLUSION: We introduced the kernel convolution theory to successfully infer the LFP from spikes, and we demonstrated that we could generate the spikes distribution from the LFP.

Non cross-linked equine collagen (Salvecoll-E gel) for treatment of complex ano-rectal fistula.

BACKGROUND: Fistula-in-ano is one of the most commonly presenting anorectal diseases. Sphincter sparing treatment options should be considered in patients with complex fistulas. Salvecoll-E gel is a native collagen deantigenated and purified, non-cross-linked equine dermal extract, with an amino acid composition identical to human collagen. METHODS: The multicentric trial study was a prospective, single-arm observational clinical study with the objective to assess the efficacy of Salvecoll-E gel for anal fistula repair in 70 patients. All patients had undergone preliminary surgical treatment consisting of positioning of a draining loosing seton that was maintained for a period of 4-6 weeks. After seton removal, a gentle debridement and washing of the fistula track was performed. The scar tissue was removed from the internal orifice. Internal opening was covered by a side-to side mucosal suture. Salvecoll-E was injected through the external opening into the fistula track, the external opening it has been opened. RESULTS: Twelve months after surgery, 55 patients demonstrated a clinically healed fistula (78,5%), 15 patients have a recurrence (21,5%). Most of the recurrences were observed in the first 6 months of treatment (13/15, 86.6%). We don't observe any worsening in CCF score. The results obtained at 1 year certainly seem satisfactory and in line with the best results published in literature using mini-invasive techniques. CONCLUSION: Salvecoll-E gel is a promising non-invasive technique for conservative treatment of anal fistulas, it's well tolerated by the patients and, in case of recurrence, reinjection or all other known techniques are feasible.

[Cardiorespiratory fitness and arterial stiffness in sedentary and not sedentary hypertensive workers]. / Relazione tra VO2 e Augmentation Index in lavoratori sedentari e non, affetti da ipertensione arteriosa.

In hypertensive subjects, arterial stiffness and arterial wave early reflection are thought to be the major factor limiting cardiac reserve and exercise capacity. Aortic augmentation index (AIx) is a measure of arterial wave reflection and stiffness, and has been associated with decreased cardiorespiratory fitness. We investigated the role of physical activity at work and its effect on such association. 25 hypertensive middle-aged workers, without history of diabetes, cardiovascular disease, renal failure and inflammatory diseases, were studied. Our study confirms that AIx provides information for the prediction of VO2 peak, being also gained with a non-invasive and practical test. Inside the two groups of sedentary and non sedentary workers, the relation between AIx and VO2 peak is still significant; whereas the non sedentary group showed a worse cardiorespiratory fitness without significantly differences in arterial stiffness.

Comparing multiple correspondence and principal component analyses with biomechanical signals. Example with turning the steering wheel.

The purpose of this article is to compare Principal Component Analysis (PCA) and a much less used method, i.e. MCA (Multiple Correspondence Analysis) with data being first changed into membership values to fuzzy space windows. For such a comparison, data from an experimental study about turning the steering wheel is used. In a didactic perspective, this article only considers one multidimensional signal with 5 components: 3 linked to the steering wheel angle and hand positions and 2 to hand effort variables. A discussion weighs out the pros and the cons of both methods with criteria such as the possibility to show complex relational phenomena, the analysis/computing time or the information loss inherent to the averaging stage (in the perspective to analyze several hundreds of large multidimensional signals).

Collection of normative data for spatial and temporal gait parameters in a sample of French children aged between 6 and 12.

OBJECTIVE: Normative data on gait is essential for clinical practice - especially in children whose gait pattern changes over time. Sets of normative gait data in healthy children vary significantly from one country to another. We decided to generate a specific reference database of gait parameters for French children. METHOD: Three hundred and eighty-two children (228 boys and 154 girls, aged between 6 and 12) were asked to walk as naturally as possible and at a self-selected speed on a GAITRite track. Velocity, step count, cadence, step time, step length, cycle time, stride length, base width, swing time, stance time, single support time and double support time were recorded. Parameters were analyzed by age group, height group and BMI. RESULTS: Velocity, step and stride length increased regularly with advancing age and height. Cadence decreased with height. All temporal parameters (except for double support) differed significantly (P<0.05) when comparing the 6-year-old group or the 7-year-old group with the 9-year-old group and older groups. A small number of temporal parameters (cadence, step time, cycle time and stance time) differed significantly when comparing 7-year-olds and 8-year-olds. Temporal parameters appeared rise in proportion height from 110 cm to 130 cm and then reached a plateau. Overweight was associated with a longer stance time and more double support. CONCLUSION: The gait pattern in French children aged between 6 and 12 differs from those recorded elsewhere in the world; although gait parameters appear to change in much the same way with age worldwide, our values (even when normalized) are different. Our local database should be of value in French studies of childhood gait disorders. Given that gait patterns do not appear to mature by the age of 12, it would be valuable to study gait patterns in a population of teenagers.

Immunologic evidence of no harmful effect of oats in celiac disease.

BACKGROUND: It was recently shown that antiendomysial antibodies (EMAs), which are highly sensitive and specific for celiac disease, are produced by intestinal mucosa. Furthermore, EMAs were detected previously in supernatant fluid from cultured duodenal mucosa specimens collected from untreated celiac disease patients and in culture media of biopsy specimens collected from treated celiac disease patients after an in vitro challenge with gliadin. Moreover, it was recently shown in vivo that oats are not toxic to celiac disease patients, suggesting the safety of oats in a gluten free-diet. OBJECTIVE: The objective was to better define the controversial role of oats in celiac disease to determine whether oats can be safely included in a gluten-free diet. DESIGN: We used an in vitro model to test whether oats induce EMA production in supernatant fluid from cultured duodenal mucosa specimens collected from 13 treated celiac disease patients. The biopsy specimens were cultured with and without peptic-tryptic digest (PT) of gliadin and avenin (from oats) and in medium alone. Samples from 5 of the 13 patients were cultured with the C fraction of PT-avenin. Indirect immunofluorescence was used to detect EMAs. RESULTS: EMAs were detected in specimens from all 13 patients after the challenge with gliadin but not after culture in medium alone. By contrast, no EMAs were detected in any of the specimens cultured with PT-avenin and its C fraction. CONCLUSIONS: Because the in vitro challenge with PT-avenin and its C fraction did not induce EMA production in treated celiac disease patients, it appears that oats have no harmful effect on celiac disease. Therefore, oats can be safely included in a gluten-free diet.

Minireview. Roles of turnover and repair of macromolecules and supramolecular structural components.

Macromolecules and supramolecular structural components that are incorrectly synthesized or are damaged by radiation or by reactive chemicals are either repaired or selectively degraded and resynthesized. In addition, turnover rates for macromolecules and supramolecular structures can be elevated by alternation of fasting and feeding periods and can be influenced by metabolic regulatory mechanisms which are governed by steady-state concentrations of labile macromolecules.

A multicenter investigation of consultation-liaison psychiatry in Italy. Italian C-L Group.

In order to evaluate the extent and quality of consultation-liaison (C-L) activity in Italy, a multicenter investigation was conducted in 17 general hospitals. All of the hospitalized patients referred to C-L psychiatry during a 1-year period were assessed by means of a specific instrument (Patient Registration Form, PRF-SF). Of 518,212 patients, 4182 were referred to C-L services (referral rate = 0.72%). Typical consultations were for female patients (60.1%), admitted to medical wards (71.5%), aged 55-75 years. Most interventions were carried out within 2 days; a minority (22%) were urgent requests. Gastrointestinal and cardiovascular disorders, and unexplained medical symptoms were the most frequent ICD-9 somatic diagnoses at admission. One-third of the patients were not informed of having been referred to C-L and half of them had a lifetime history of psychiatric disturbances. Most frequent ICD-10 psychiatric diagnoses were neurotic, stress-related, and somatoform syndromes (33.1%), affective syndromes (19.4%), and organic mental syndromes (10.7%). Two-thirds of the patients were given only one consultation whereas the reminder received two to four follow-up visits. The rate of transfer to psychiatric wards was low (2.1%). Psychopharmacological treatment was suggested in 65% of cases, and 75.5% of the patients were referred to community psychiatric care at discharge. The implications of the findings are discussed.

QT dispersion variability and myocardial viability in acute myocardial infarction.

The aim of this study was to evaluate QT dispersion in acute and sub-acute stages of myocardial infarction and clarify the relationship between QT dispersion and myocardial viability. We studied 95 patients with acute myocardial infarction. The QT dispersion values were compared to those of a control group of 50 healthy subjects. In the patients with acute myocardial infarction dispersion of ventricular repolarization was evaluated on the standard electrocardiograms obtained at the time of admission and ten days later. Two-dimensional echocardiography examination was performed to assess and compare left ventricular wall motion at different stages. QT dispersion values were increased in patients with acute myocardial infarction and levels were higher in the early than in late phases. A better recovery of QT dispersion was found in those patients who demonstrated improvement of left ventricular contractility. The modifications of QT dispersion can reflect the alterations of myocardial contractility.

Cardiac valve involvement in systemic lupus erythematosus and primary antiphospholipid syndrome: lack of correlation with antiphospholipid antibodies.

The aim of this study was to determine the prevalence of cardiac valve disease in systemic lupus erythematosus or in patients with primary antiphospholipid syndrome and to assess the role of the antiphospholipid antibodies as risk factor for endocardial lesions. We studied 39 consecutive patients with systemic lupus erythematosus (mean age 34 +/- 12 years, 38 female and one male), 20 women with primary antiphospholipid syndrome (mean age 32 +/- 4 years) and 20 normal subjects (mean age 35 +/- 8 years, 15 female and five male). All patients with primary antiphospholipid syndrome had increased levels of serum anticardiolipin antibodies and recurrent fetal abortions; some of them also had arterial and/or venous thrombosis and/or thrombocytopenia. M-mode, two-dimensional and Doppler echocardiography were performed in all patients. IgG anticardiolipin antibodies were measured by an enzyme-linked immunosorbent assay. Valvular lesions were observed in 15 patients (38%) with systemic lupus erythematosus. These abnormalities included: mitral valve thickening or vegetation, mitral valve prolapse and aortic valve vegetation; mitral, aortic and tricuspid regurgitation; mitral stenosis. None of the patients with primary antiphospholipid syndrome and of the normal subjects was found to have valvular abnormalities. In systemic lupus erythematosus, high levels of anticardiolipin antibodies were detected in 73% of the patients with valvular lesions and in 67% of the patients without valvular lesions (P > 0.05). We conclude that valvular involvement is frequent in patients with systemic lupus erythematosus but it is apparently unrelated to antiphospholipid autoimmunization.

Signal-averaged electrocardiography and echocardiography in the evaluation of myocardial involvement in progressive systemic sclerosis.

To assess the myocardial involvement in progressive systemic sclerosis we evaluated the presence of late potentials by signal-averaged electrocardiography (signal-averaged ECG) and the left ventricular function by M-mode, two dimensional and Doppler echocardiography. Fifteen outpatients, 7 with diffuse progressive systemic sclerosis and 8 with CREST syndrome variant, without clinical or electrocardiographic evidence of cardiac disease were studied and compared with 18 normal subjects. Late potentials occurred in 5 out of 15 progressive systemic sclerosis patients (33%) with a significant difference versus controls (P < 0.05) and were present only in the patients with diffuse progressive systemic sclerosis (P < or = 0.001 vs. controls). All progressive systemic sclerosis patients showed a normal left ventricular systolic function. Abnormal left ventricular filling was found in 9 progressive systemic sclerosis patients (5 with diffuse progressive systemic sclerosis and 4 with CREST). A more severe impairment of the mean values of diastolic function indexes was found in diffuse progressive systemic sclerosis than in CREST. In all diffuse progressive systemic sclerosis patients at least one method showed altered results, whereas half the CREST patients showed no pathological findings with both techniques. These results confirm a lower myocardial involvement in the CREST syndrome than in diffuse progressive systemic sclerosis and consequently this is probably related to a better prognosis.

Suture materials and other factors associated with tissue reactivity, infection, and wound dehiscence among plastic surgery outpatients.

The most common complications in plastic surgery are tissue reactivity, infections, and wound dehiscence. In the literature, there are only a few studies with sample sizes large enough and methods of statistical analysis appropriate for evaluating the role of suture materials in inducing such complications. In the 1000 plastic surgery outpatients in this study, the association of different suture materials, individual patient characteristics, surgeon skill, and wound site and length with postoperative wound complications (i.e., tissue reactivity, infection rate, and wound dehiscence) were investigated. No substantial differences were found between the different suture materials and suturing techniques. A moderate increase in the risk of tissue reactivity for silk and polyglactin 910 and a protective effect of thinner internal sutures were observed. In multivariate analysis, such differences were not statistically significant. Male sex [odds ratio (OR), 1.7; 95 percent confidence interval (CI), 1.06 to 2.72] and older age (OR, 2.34; 95 percent CI, 1.36 to 4.05) were found to be the most important risk factors for tissue reactivity and infection rate (male sex: OR, 5.1; 95 percent CI, 1.7 to 15.9; older age: OR, 5.6; 95 percent CI, 1.9 to 16), whereas younger age was associated with an increased risk of dehiscence (OR, 3.06; 95 percent CI, 1.41 to 6.65). Wounds on the lower limbs showed a lower risk of tissue reactivity and wounds on the back a higher risk of dehiscence. Wound length was associated with the risk of tissue reactivity in one-layer sutures (OR, 2.92; 95 percent CI, 1.51 to 5.65). An increased risk of both tissue reactivity (OR, 1.53; 95 percent CI, 1.03 to 2.27) and dehiscence (OR, 2.44; 95 percent CI, 1.1 to 5.43) was observed for operations performed by less-experienced surgeons. Rather than factors related to suture materials and different surgical techniques, and with the exception of surgeon experience, general characteristics of the patients (i.e., sex and age) and of the wounds (i.e., length and site) seemed to be primarily responsible for local wound complications.

Identification of cells secreting a thymostimulin-like substance and examination of some histoenzymatic pathways in aging avian primary lymphatic organs: I. thymus.

Thymi of adult chickens (White Leghorn strain), ages of 6, 18, 45, days and 1, 3, 6, months, were studied by histological and histochemical stainings, histoenzymatic reactions (LDH, SDH, alpha-GPDH, NADH, NADPH, Ca++ dependent ATPase, pH 8.5) and by anti-thymostimulin immunoreaction. Positive reactions for thymostimulin-like substance, mucopolysaccharides and enzymatic activities were located in different epithelial compartments of the cortical and medullary zones. In 3 and 6 month-old chickens, there was a progressive reduction of the cortical area and of the number of cortical and medullary epithelial cells, and, in the thymi of the 6 month-old chickens, a partial decline in the immunological reactivity to anti-TS, but the intensity of the histochemical and enzymatic reactivities, in comparison with the thymi of the youngest chickens, was not decreased. This may suggest that the cortical and medullary epithelial cells still present in these thymi are capable of secreting and expressing activities and, thus, may maintain their functions.

Identification of cells secreting a thymostimulin-like substance and examination of some histoenzymatic pathways in aging avian primary lymphatic organs: II. Bursa of Fabricius.

The Bursa of Fabricius of 15 day, 1-, 3-, and 6 month-old adult chickens (White Leghorn strain) were studied by histological and histochemical staining, histoenzymatic reactions (LDH, SDH, a-GPDH, NAD, NADPH, Ca++-dependent ATP-ase, pH 8.5) and by anti-thymostimulin immunoreaction. Positive reactions for mucopolysaccharides and enzymatic activities were located in the epithelia of the follicles, i.e. in follicle-associated-epithelium (FAE), inter-follicle-epithelium (IFE) and in different epithelial compartments of cortical and medullary zones. Positive reaction for thymostimulin-like (TS-like) substance was restricted to FAE cells and weakly to the basal lamina of IFE. In 6-month-old chickens, the FAE cells disappeared; the phenomenon of bursal regression was evident, although not all the follicles were involved. In the few still normal follicles, the good reactivity to the enzymes tested suggests that residual physiological activity is still present, even if reduced.

Endoscopic ultrasonography in the evaluation of leiomyoma and extramucosal cysts of the esophagus.

BACKGROUND/AIMS: Leiomyoma is the most common type of benign esophageal tumor, whereas extramucosal cysts of the esophagus are congenital anomalies frequently asymptomatic in the adult and in most cases detected incidentally on chest x-ray. It is worthwhile considering these conditions together, because they present similar diagnostic and surgical problems. Conventional imaging tests do not lead to a precise diagnosis. The purpose of this study was to evaluate the use of endoscopic ultrasonography in the diagnosis of, and planning of treatment modalities for, these conditions. METHODOLOGY: Fifteen patients with esophageal leiomyoma and seven patients with extramucosal esophageal cysts were studied with endoscopic ultrasonography using an Olympus GF- EU-M3 instrument with a 7.5-12 MHz echoprobe. In all patients, the results of endoscopic ultrasonography were compared with the histology of the resected specimens. RESULTS: The histology of the resected specimens confirmed the endosonographic diagnosis in all patients. No malignancy was found in any specimen. CONCLUSIONS: Endoscopic ultrasonography is very accurate in visualizing these lesions and differentiating cystic from solid submucosal esophageal masses; in addition, the test can establish the exact location of the mass in relation to the esophageal wall and mediastinum. Therefore, endoscopic ultrasonography has a great impact in confirming the diagnosis of leiomyoma and extramucosal cysts of the esophagus and facilitates therapeutic decision-making because of its capacity to clearly define the size, layer of the origin, and pattern of the mass.

The phosphorylation of nuclear proteins in normal and transformed cells.

Normal (Rat 1) and transformed cells (middle T antigen-transformed derivative 3C3) were grown in the presence of 32P-orthophosphate. 32P-labelled nuclear proteins were fractionated by means of two-dimensional gel electrophoresis and detected by autoradiography. The comparative analysis of the autoradiographs of the normal and transformed cells revealed differences in the phosphorylation patterns of histone and low-molecular-mass high mobility group proteins (HMG). Three of the HMG proteins were highly phosphorylated in the transformed cells, and the analysis of their phosphorylation sites showed that these HMG proteins were phosphorylated on serine and threonine but not on tyrosine residues.

Clinical aspects and treatment of inflammatory abdominal aortic aneurysms.

An increasing number of inflammatory abdominal aortic aneurysms are reported today, although it is not clear whether these are nosologically independent lesions or a particular evolution of atherosclerotic aneurysms with enhanced phlogistic processes and fibrous reaction. Several pathogenetic theories have been proposed (microfissuration, autoimmunity, lymphatic stasis); clinical symptoms are characterised by the frequent involvement of contiguous retroperineal structures (in particular the urinary excretory tract and duodenum) which may be dislocated or compressed by the neoformation. CT or NMR appear to be the instrumental tests which give the most reliable diagnosis regarding the suspected inflammatory nature of the aneurysm. A correct pre-operative diagnosis is particularly important given that the morphological peculiarities (fibrosis and tenacious synechiae) add considerable pitfalls and difficulties to the operation. In this respect, the use of special technical devices, such as minimum dissection, permit a marked reduction of perioperative complications.

Histones of human lung carcinoma and human lung tissue. Analysis by two-dimensional electrophoresis.

Histones prepared from human lung and human lung carcinoma were analyzed by a 2-dimensional electrophoresis method able to separate histone subfractions. The comparative analysis of electrophoretograms showed differences in the relative amounts of H1, H2A, and H3 histone subfractions extracted from human lung and human lung carcinoma chromatin.