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PubMed1994

Connective tissue tumors in patients with cutaneous melanoma.

BACKGROUND: A possible relation between cutaneous melanoma and connective tissue tumors has been described. OBJECTIVE: After the observation that a group of our patients had both cutaneous melanoma and a soft tissue sarcoma, we elected to review this formally. Eleven patients with both diagnoses were identified and are described. METHODS: A computer search through the Medical Records Department and the Tumor Registry of the Massachusetts General Hospital identified seven men and four women with the diagnoses of melanoma and malignant bone or soft tissue sarcoma. The medical records and pathology specimens of all tumors were reviewed. RESULTS: In three patients, the two tumors were diagnosed within 1 year of each other, in seven, the diagnosis of melanoma was made first, and in one, melanoma was diagnosed after the connective tissue lesion. The interval between the two diagnoses ranged up to 13 years. Although the locations and types of melanoma were typical, some of the connective tissue tumors were unusual; there were two sacral chordomas. In two instances, the melanoma and connective tissue tumor were anatomically close; the sarcoma developed at the edge of the resection of the prior melanoma in one patient. None of the tumors developed in previously irradiated tissues, and in no instance did the second tumor appear to be caused by the therapy received for the first. None of the patients had a family history of melanoma. Four patients had other cancers in addition to the melanoma and connective tissue tumor. CONCLUSION: Although these patients were seen in a referral center, it is our impression (based on the total number of patients with connective tissue tumors seen and the incidence of melanoma in the general population) that observing 11 patients with both types of tumors is greater than would be expected by chance.

Adult↗
PubMed2001

Intra- and inter-areal connections between the primary visual cortex V1 and the area immediately surrounding V1 in the rat.

We have qualitatively and quantitatively analysed the anatomical connections within and between rat primary visual cortex (V1) and the rim region surrounding area V1, using both ortho- and retrograde anatomical tracers (biotinylated dextran amine, biocytin, cholera toxin b subunit). From the analysis of the projection patterns, and with the assumption that single points in the rat visual cortex, as in other species, have projection fields made up of multiple patches of terminals, we have concluded that just two V1 recipient areas occupy the entire rim region: an anterolateral area, probably homologous with V2 in other mammals, previously named Oc2L, and a medial area, corresponding to Oc2M. A non-reciprocal projection from the anterolateral area to the medial area was identified. Small injections (300-600microm uptake zone diameter) of the anatomical tracers in area V1, or in the rim region, label orthograde intra-areal connections from each injection site to offset small patches. This is found in all regions of the rim and within at least the relatively expanded central dorsal field representation of V1. From the extent of these projections in V1 and the two rim regions, we have estimated that the neurons at the injection site send diverging laterally spreading projections to other neurons whose receptive fields share any part of the area included in the pooled receptive fields of the neurons at the injection site. Orthogradely labelled inter-areal feedforward projections from V1 to either rim region are estimated to diverge in their projections to neurons that share any part of the area of the pooled receptive fields of the V1 intra-areal connectional field of the same injection. The orthogradely labelled feedback projections to V1, from injection sites in either rim region, reach V1 neurons whose pooled receptive fields match those of the neurons in the rim injection site, i.e. with no divergence. Despite patchy anatomical connectional fields, our estimates indicate that visual space is represented continuously in the receptive fields of neurons postsynaptic to each intra- or inter-areal field of orthograde label. We suggest that, despite the absence of regularly mapped functions in rat V1 (e.g. regularly arranged orientation specificity), which in other species (e.g. primates and cats) relate to the patchy connectional patterns, the rat visual cortex intra- and inter-areal anatomical connections follow similar patterns and scaling factors to those in other species.

Animals↗
PubMed2001

A correlative physiological and morphological analysis of monosynaptically connected propriospinal axon-motoneuron pairs in the lumbar spinal cord of frogs.

Intracellular stimulation of single propriospinal axons evoked excitatory postsynaptic potentials (EPSPs) in lumbar motoneurons. Mean EPSP amplitudes differed by two orders of magnitude when measured in different connections. After analyzing the distribution of mean amplitudes of 47 single-fiber EPSPs, two populations of responses could be defined: (1) those with mean amplitudes between 0.1 and 1.2 mV (mean+/-S.D.: 0.48+/-0.30 mV, 34 pairs), which is in the range of values typical for single-fiber EPSPs evoked by stimulation of supraspinal fibers and primary muscle afferents, (2) those with mean amplitudes between 1.6 and 8 mV (4.2+/-2.0 mV, 13 pairs). Both populations of responses had similarly short latencies and rise times and responded similarly to paired-pulse stimulation, consistent with monosynaptic transmission. However, the high-efficacy connections had significantly smaller coefficients of variation of EPSPs, as well as increased quantal content and quantal size. Tetanic stimulation gradually depressed the amplitude of large EPSPs by 81-86%, but did not affect small EPSPs. Recovery of large EPSPs was exponential with a time constant of 3-5.6 min. During post-tetanic depression the amplitude ratio between the test and conditioned EPSPs evoked by paired-pulse stimulation was not changed but the coefficient of variation was increased, suggesting that the depression was due to depletion of synaptic vesicles available for release.Intracellular labeling of seven electrophysiologically studied propriospinal axon-motoneuron pairs revealed that the number of axon varicosities establishing close appositions with dendrites of the labeled motoneuron was higher for connections where large-amplitude EPSPs were recorded. These varicosities were more often located on proximal dendrites of motoneurons than those of low-efficacy connections. In addition, the number of boutons in highly effective connections was several times lower than the maximal number of available quanta estimated from physiological data, implying that the large EPSPs may be generated by multivesicular release from presynaptic boutons. We conclude that the efficacy and related mode of use-dependent modulation of propriospinal connections is determined by a number of factors, including the number and position of synaptic contacts and the number of active zones or vesicles available for release.

Animals↗
PubMed2002

The connections between the frustrated chaos and the intermittency chaos in small Hopfield networks.

In a previous paper we introduced the notion of frustrated chaos occurring in Hopfield networks [Neural Networks 11 (1998) 1017]. It is a dynamical regime which appears in a network when the global structure is such that local connectivity patterns responsible for stable oscillatory behaviors are intertwined, leading to mutually competing attractors and unpredictable itinerancy among brief appearance of these attractors. Frustration destabilizes the network and provokes an erratic 'wavering' among the orbits that characterize the same network when it is connected in a non-frustrated way. In this paper, through a detailed study of the bifurcation diagram given for some connection weights, we will show that this frustrated chaos belongs to the family of intermittency type of chaos, first described by Berge et al. [Order within chaos (1984)] and Pomeau and Manneville [Commun. Math. Phys. 74 (1980) 189]. Indeed, the transition to chaos is a critical one, and all along the bifurcation diagram, in any chaotic window, the duration of the intermittent cycles, between two chaotic bursts, grows as an invert ratio of the connection weight. Specific to this regime are the intermittent cycles easily identifiable as the non-frustrated regimes obtained by altering the values of these same connection weights. We will more specifically show that anywhere in the bifurcation diagram, a chaotic window always lies between two oscillatory regimes, and that the resulting chaos is a merging of, among others, the cycles at both ends. The strength (i.e. the duration of its oscillatory phase before the chaotic burst) of the first cycle decreases while the regime tends to stabilize into the second cycle (with the strength of this second cycle increasing) that will finally get the control. Since in our study, the bifurcation diagram concerns the same connection weights responsible for the learning mechanism of the Hopfield network, we will discuss the relations existing between bifurcation, learning and control of chaos. We will show that, in some cases, the addition of a slower Hebbian learning mechanism onto the Hopfield networks makes the resulting global dynamics to drive the network into a stable oscillatory regime, through a succession of intermittent and quasiperiodic regimes. Finally, we will present a series of possible logical steps to manually construct a frustrated network.

Computer Simulation↗
PubMed2002

Lateral connectivity and contextual interactions in macaque primary visual cortex.

Two components of cortical circuits could mediate contour integration in primary visual cortex (V1): intrinsic horizontal connections and feedback from higher cortical areas. To distinguish between these, we combined functional mapping with a new technique for labeling axons, a recombinant adenovirus bearing the gene for green fluorescent protein (GFP), to determine the extent, density, and orientation specificity of V1 intrinsic connections and V2 to V1 feedback. Both connections cover portions of V1 representing regions of visual space up to eight times larger than receptive fields as classically defined, though the intrinsic connections are an order of magnitude denser than the feedback. Whereas the intrinsic connections link similarly oriented domains in V1, V2 to V1 feedback displays no such specificity. These findings suggest that V1 intrinsic horizontal connections provide a more likely substrate for contour integration.

Adenoviridae↗
PubMed1999

Management of late complications after classic Fontan procedure by conversion to total cavopulmonary connection.

Classic Fontan procedures, such as atriopulmonary connection or atrioventricular connection, are associated with right atrial dilatation and several late complications. Seven patients with univentricular heart who presented with exercise intolerance (n = 7), severely dilated right atrium (n = 7) with pulmonary vein compression (n = 3), atrial arrhythmias resistant to medical treatment (n = 4), cyanosis (n = 4), diffuse effusions and oedema (n = 1), and protein-losing enteropathy (n = 1), underwent conversion to total cavopulmonary connection 5.8-14.4 years after a previous atriopulmonary connection (n = 6) or atrioventricular connection (n = 1). A 14-year-old boy who, preoperatively, was in ventricular failure and a very poor state died early after conversion because of low cardiac output. All survivors had either marked or partial clinical improvement with regression of cardiomegaly, absence of pulmonary vein compression or cyanosis, and recovery of sinus rhythm. Conversion to total cavopulmonary connection appears to be effective in the treatment of late complications after classic Fontan procedures. It should be considered early in symptomatic patients, before significant ventricular dysfunction and clinical deterioration ensue.

Adolescent↗
PubMed2000

Neonatal pulmonary artery banding does not compromise the short-term function of a Damus-Kaye-Stansel connection.

BACKGROUND: The surgical approach of neonates with a functionally univentricular heart, transposition of the great arteries and excessive pulmonary bloodflow remains a challenge. Pulmonary artery banding remains a valuable option, but may induce ventricular hypertrophy, restriction of the bulboventricular foramen and dysplastic changes of the pulmonary valve. These secondary changes might compromise a later Damus-Kaye-Stansel connection because of pulmonary regurgitation but also a subsequent Fontan repair because of ventricular hypertrophy. The aim of this study is to investigate whether a previous pulmonary artery banding might compromise the function of a Damus-Kaye-Stansel connection. METHODS: Thirteen neonates underwent pulmonary artery banding for functionally univentricular heart, transposition of the great arteries and pulmonary hypertension. Coarctation repair was associated in seven patients. All but one survived the operation. The twelve survivors underwent at a second stage a Damus-Kaye-Stansel connection after a mean interval of 1.1 years. The length of this interval was dictated by the degree of ventricular hypertrophy, the restriction of the bulboventricular foramen and by the degree of cyanosis. The Damus-Kaye-Stansel connection was constructed without any foreign material and with resorbable sutures. Associated procedures were: Glenn/hemi-Fontan (8 pts), Blalock-shunt (2 pts), biventricular correction with a homograft (1 pt), Fontan repair (1 pt). Four patients underwent successfully a Fontan repair at a third stage; seven patients are waiting for such repair. RESULTS: All patients survived the second and third stage of this surgical approach. The mean follow-up after the Damus-Kaye-Stansel connection was 2.5 years. Echocardiography at the last follow-up revealed: PR grade 0 (1 pt), grade 1 (8 pts), and grade 2 (3 pts). All patients - except one patient with a systolic gradient of 24 mmHg - had laminar flow without any gradient in the ascending aorta. All patients, including those who underwent a definitive repair, are doing extremely well. CONCLUSION: This experience demonstrates that a neonatal pulmonary artery banding does not compromise the function neither of a Damus-Kaye-Stansel connection nor a Fontan repair.

Abnormalities, Multiple↗
PubMed2003

Combined functional MRI and tractography to demonstrate the connectivity of the human primary motor cortex in vivo.

In this study, we combined advanced MR techniques to explore primary motor cortex (M1) connectivity in the human brain. We matched functional and anatomical information using motor functional MRI (fMRI) and white matter tractography inferred from diffusion tensor imaging (DTI). We performed coregistered DTI and motor task fMRI in 8 right-handed healthy subjects and in 1 right-handed patient presenting with a left precentral tumour. We used the fast-marching tractography (FMT) algorithm to define 3D connectivity maps within the whole brain, from seed points selected in the white matter adjacent to the location of the maximum of fMRI activation. Connectivity maps were then anatomically normalised and analysed using statistical parametric mapping software (SPM99) allowing group comparisons (left versus right hemisphere in control subjects and patient versus control subjects). The results demonstrated, in all control subjects, strong connections from M1 to the pyramidal tracts, premotor areas, parietal cortices, thalamus, and cerebellum. M1 connectivity was asymmetric, being more extensive in the dominant hemisphere. The patient had differences in M1 connectivity from the control group. Thus, fMRI-correlated DTI-FMT is a promising tool to study the structural basis of functional networks in the human brain in vivo.

Adult↗
PubMedDate not supplied

Afferent connectivity to different functional zones of the optic tectum in goldfish.

This work studies the afferent connectivity to different functionally identified tectal zones in goldfish. The sources of afferents contributed to different degrees to the functionally defined zones. The dorsocentral area of the telencephalon was connected mainly with the ipsilateral anteromedial tectal zone. At diencephalic levels, neurons were found in three different regions: preoptic, thalamic, and pretectal. Preoptic structures (suprachiasmatic and preoptic nuclei) projected mainly to the anteromedial tectal zone, whereas thalamic (ventral and dorsal) and pretectal (central, superficial, and posterior commissure) nuclei projected to all divisions of the tectum. In the mesencephalon, the mesencephalic reticular formation, torus longitudinalis, torus semicircularis, and nucleus isthmi were, in the anteroposterior axis, topographically connected with the tectum. In addition, neurons in the contralateral tectum projected to the injected zones in a symmetrical point-to-point correspondence. At rhombencephalic levels, the superior reticular formation was connected to all studied tectal zones, whereas medial and inferior reticular formations were connected with medial and posterior tectal zones. The present results support a different quantitative afferent connectivity to each tectal zone, possibly based on the sensorimotor transformations that the optic tectum carries out to generate orienting responses.

Afferent Pathways↗
PubMedDate not supplied

Comparative structural connectivity spectra analysis (CoSCoSA) models of steroid binding to the corticosteroid binding globulin.

A three-dimensional quantitative spectrometric data-activity relationship (3D-QSDAR) model was developed that is built by combining NMR spectral information with structural information in a 3D-connectivity matrix. The 3D-connectivity matrix is built by displaying all possible carbon-to-carbon connections with their assigned carbon NMR chemical shifts and distances between the carbons. Selected 2D (13)C-(13)C COrrelation SpectroscopY (COSY) (through-bond nearest neighbors) and selected theoretical 2D (13)C-(13)C distance connectivity spectral slices from the 3D-connectivity matrix to produce a relationship among the spectral patterns for 30 steroids binding to corticosteroid binding globulin. We call this technique a comparative structural connectivity spectra analysis (CoSCoSA) modeling. A CoSCoSA principal component linear regression model based on the combination of (13)C-(13)C COSY and (13)C-(13)C distance spectra principal components (PCs) had an r(2) of 0.96 and a leave-one-out (LOO) cross-validation q(2) of 0.92. A CoSCoSA parallel distributed artificial neural network (PD-ANN) model based on the combination of (13)C-(13)C COSY and (13)C-(13)C distance spectra had an r(2) of 0.96, a leave-three-out q(3)(2) of 0.78, and a leave-ten-out q(10)(2) of 0.73. CoSCoSA modeling attempts to uniquely combine the quantum mechanics information from the NMR chemical shifts with internal molecular atom-to-atom distances into an accurate modeling technique. The CoSCoSA modeling technique has the flexibility and accuracy to outperform the cross-validated variance q(2) of previously published quantitative structure-activity relationship (QSAR), quantitative spectral data-activity relationship (QSDAR), self-organizing map (SOM), and electrotopological state (E-state) models.

Binding Sites↗
PubMed1996

The Four-Connected Net in the CeCu(2) Structure and Its Ternary Derivatives. Its Electronic and Structural Properties.

The crystallochemistry of and the bonding in the orthorhombic four-connected nets of BaIn(2) (CeCu(2) structure) and of CaPtSn (TiNiSi structure, a derivative of the CeCu(2) structure) are analyzed with approximate molecular orbital calculations. Following the Zintl concept, in BaIn(2) the In(-) ions are isoelectronic with group IV tin and should adopt a four-connected structure. In contrast to alpha-tin, which has a cubic diamond structure, the indium ions in BaIn(2) build up an orthorhombic three-dimensional four-connected net containing distorted tetrahedra and ladder polymers of four-membered rings. In the CeCu(2) structure (space group Imma) two bond angles in these distorted tetrahedra are fixed at 90 degrees. The four-connected net in the CeCu(2) structure is topologically related to the layers in black phosphorus (space group Cmca). In CaPtSn (TiNiSi structure) the orthorhombic four-connected net is formed by (PtSn)(2)(-) ions in an ordered arrangement. Calculations on BaIn(2) and CaPtSn show that the four-connected nets are increasingly stabilized as the valence electron count is increased from 16 to 30 valence electrons per 4 formula units. For more than 30e, the nets are destabilized due to filling of M-E antibonding states. Structural data obtained by precise single crystal investigations for the TiNiSi series CaPdIn (20e), CaPdSn (24e), CaPdSb (28e), and CaAgSb (32e), confirm the results of the extended Hückel calculations. We find an interesting and understandable angular asymmetry of the tetrahedral sites in these ternary compounds.

Journal Article↗
PubMedDate not supplied

Post-tetanic modification of the efficiency of excitatory transmission in neural networks including interhemispheric connections.

This is the first report of modifiable reciprocal transcallosal monosynaptic excitatory connections, detected in in vivo experiments in the rat motor cortex by recording of multineuron activity and cross-correlation analysis. High-frequency microstimulation of a small group of cortical neurons in one hemisphere was shown to alter the efficiency of transcallosal excitatory connections, and also altered the efficiency of ipsilateral connections in both hemispheres. Post-tetanic changes consisted of long-term potentiation and depression. Neurons producing spike trains were found to have better conditions (compared with other neurons) for long-term potentiation of inputs converging on them. Synapses formed by axon collaterals of a given callosal cell on several neurons could simultaneously induce both long-term potentiation and long-term depression, while a given callosal neuron could simultaneously show long-term potentiation in some synapses and long-term depression in others. After microstimulation there were increases in the number of background-active callosal neurons, along with increases in the number and efficiency of transcallosal connections, while the number and efficiency of ipsilateral connections decreased. These data lead to the conclusion that ipsilateral inhibition is more effective than transcallosal inhibition. Microstimulation modified the pattern of initially existing connections between the many elements of ensembles including callosal cells in both hemispheres.

Action Potentials↗
PubMedDate not supplied

Cell type specificity of local cortical connections.

The function of the cerebral cortex is dependent on the precise organization of the circuits formed by its component neurons. The connections between neurons are not random, but are specific at multiple levels of organization. For example, each cortical area connects to only a selected subset of other areas and within any given area the axonal and dendritic arbors of individual neurons arborize in precise, layer-specific patterns (for review see Felleman & Van Essen, 1991; Callaway, 1998). In each layer there are dendrites from multiple cell types including cells with somata both within and outside that layer. Anatomical studies have shown that axons arborizing in a particular cortical layer can connect selectively onto dendrites of some cell types in the layer, while avoiding the dendrites of other cell types (e.g. Freund & Gulyas, 1991; Hornung & Celio, 1992; Staiger et al., 1996). These cell type specific connections are, however, difficult to elucidate with anatomical methods, so the frequency of such specificity has remained elusive. Recent experimental methods combining intracellular recording of single neurons with focal neuronal stimulation by uncaging glutamate with light ("photostimulation") have made the analysis of cell type specific cortical connections more tractable. These studies show that cell type specificity of connections is prevalent in cortex. Here I review photostimulation-based studies investigating the laminar sources of cortical input to distinct cell types in the visual and somatosensory cortices of rats and the primary visual cortex of monkeys.

Animals↗
PubMed2003

Non-invasive mapping of connections between human thalamus and cortex using diffusion imaging.

Evidence concerning anatomical connectivities in the human brain is sparse and based largely on limited post-mortem observations. Diffusion tensor imaging has previously been used to define large white-matter tracts in the living human brain, but this technique has had limited success in tracing pathways into gray matter. Here we identified specific connections between human thalamus and cortex using a novel probabilistic tractography algorithm with diffusion imaging data. Classification of thalamic gray matter based on cortical connectivity patterns revealed distinct subregions whose locations correspond to nuclei described previously in histological studies. The connections that we found between thalamus and cortex were similar to those reported for non-human primates and were reproducible between individuals. Our results provide the first quantitative demonstration of reliable inference of anatomical connectivity between human gray matter structures using diffusion data and the first connectivity-based segmentation of gray matter.

Adult↗
PubMed2004

The corporo-glans ligament: description and functional significance of a ligament connecting the corpora cavernosa to the glans penis.

The two corpora cavernosa (CC) end blindly under cover of the glans penis (GP). The method of attachment of the CC to the GP could not be traced in the literature. The current communication investigated the hypothesis of a ligamentous attachment existing between the two corporal ends and the GP. In all, 18 male cadaveric specimens were studied by direct dissection and histologically. Six were neonates and 12 adults (mean age 32.3+/-10.6 s.d. y). After examining and photographing the connection between the CC and GP, sagittal, parasagittal, and coronal sections of the connection were stained and studied microscopically. A triangular fibrous tissue band connected the distal blind ends of the two CC with the GP. The base of this band was attached to the tunica albuginea of the two CC, while the apex was continuous with the fibrous septa between the sinusoids of the cavernous tissue of the GP. Microscopically, the ligament consisted of collagen and elastic fibers; in some sections, the collagen fibers of the tunica albuginea were continuous with those of the band. A band of collagen and elastic fibers could be identified connecting the two CC to the GP; we term it the 'corporo-glans ligament'. This ligament presumably affords the connection with rigidity, flexibility, and tissue strength. We suggest that it firmly connects the GP to the CC during penile thrusting. Further studies are required to assess the possible role of this ligament in erectile dysfunction.

Adolescent↗
PubMed2005

Altered functional connectivity related to white matter changes inside the working memory network at the very early stage of MS.

Functional magnetic resonance imaging (fMRI) using paced auditory serial addition test (PASAT) as paradigm was used to study the functional connectivity in 18 patients at the very early stage of multiple sclerosis (MS) compared with 18 controls, to determine the existence of circuitry disturbance inside the working memory network and its relationship with white matter abnormalities assessed by conventional MRI and magnetization transfer ratio (MTR) imaging. The left BA 45/46 was selected as the seed region to compute correlation maps with other brain regions. After obtaining the correlation map for each subject, between-group comparisons were performed using random effect procedure. Compared with controls, patients did not show any greater functional connectivity between left BA 45/46 and other regions during PASAT. In contrast, decrease in functional connectivity was observed in patients between left BA 45/46 and left BA 9, right BA 3, and the anterior cingulate cortex (BA 24). In patients, no correlations were found between altered functional connectivity and clinical data. However, functional connectivity observed between left BA 45/46 and BA 24 in patients was correlated with the MTR of normal appearing white matter, and with brain T(2) lesion load. Altered functional connectivity is present inside the working memory network of patients at the very early stage of MS and is related to the extent of diffuse white matter changes.

Acoustic Stimulation↗
PubMed2000

Connectivity and HIV-1 infection: role of CD4(+) T-cell counts and HIV-1 RNA copy number.

Following primary infection with human immunodeficiency virus (HIV)-1, antibodies against specific HIV-1 epitopes are elicited. However, non-HIV-1 specific antibodies, including autoantibodies, also arise. In fact, it has been proposed that such autoantibodies have an important role in the pathogenesis of HIV-1 infection. Because an imbalance in connectivity has been associated with autoimmune processes, we investigated the connectivity status of HIV-1-infected individuals. Moreover, we tested the possible role of viral load and CD4(+) T-cell counts, in connectivity, because these parameters appear to be important in the prognosis of HIV-1 infection. Results show that indeed, there is an alteration in connectivity in these patients, both for immunoglobulin (Ig)G and IgM, which is an immune alteration not previously identified in HIV-1 infection. In addition, our results show that viral load and CD4(+) T-cell counts are both equally important in defining the characteristic pattern of connectivity in HIV-1-infected individuals, and that neither is independently responsible for alterations in patient connectivity status.

Adult↗
PubMed2001

Connectivity patterns in tuberculosis and leprosy patients are indistinguishable from that of healthy donors.

Connectivity, the self-defined interactions between antigen-recognising molecules in a network system can in part be assessed by measuring the reactivity of a given serum against an ordered set of immunoglobulin (Ig)G F(ab')2 fractions, separated by means of isoelectric focusing so that, the serum reactivity against the whole set of fractions defines a characteristic pattern of connectivity. Deviations from the normal condition (healthy donors) have so far been documented for two autoimmune diseases: systemic lupus erythematosus (SLE) and pemphigus vulgaris, as well as for human immunodeficiency virus (HIV)-1 infection. We tested here if bacterial infections lead to alterations in connectivity. In addition, we wanted to test if two antigenically related bacteria would produce similar or otherwise distinctive connectivity patterns. Connectivity analysis was applied on the sera from tuberculosis and leprosy patients and the sera from healthy donors were used as control. No statistically significant differences between the three groups studied were found. These results have implications for theories that set the origin of autoimmune diseases in microbial infections. To the best of our knowledge, this is the first attempt to analyze the connectivity status in bacterial infections.

Adult↗