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Supplemental Digital Content is available in the text., Background: Diagnosis and treatment for developmental dysplasia of the hip (DDH) varies greatly depending on condition severity, age at diagnosis, and professional opinion. Little is known about patient experiences across the globe. We aimed to characterize global patient and caregiver experiences during DDH care and to highlight patient-identified priorities. Methods: We developed a cross-sectional survey in collaboration with 7 DDH outreach organizations. DDH patients and/or their caregivers (above 18 y old) were invited to complete an international online survey about their experiences. Participants were recruited through web media of all collaborating organizations. Data collection took place over 3 months. Descriptive statistics were used to analyze quantitative results. Qualitative content analysis was used to categorize open-ended responses. Results: A total of 739 participants completed the survey, representing 638 (86.3%) parents/guardians of DDH patients, and 101 (13.7%) patients. Three hundred eighty-six (52.2%) participants received diagnosis by 3 months of age; mean age of diagnosis was 15.96 months (90% confidence interval=12.04, 19.91). Of 211 participants with family history of DDH, 68 (32.3%) did not receive DDH screening. Of 187 patients born breech, 82 (43.9%) did not receive DDH screening. In total, 36/94 (38.3%) participants with both family history and breech birth did not receive DDH screening. Most participants reported treatment (696/730, 95.3%), including bracing (n=461) surgery (n=364), and/or closed reduction (n=141). A total of 144 patients reported >1 surgery; 82 reported >3 surgeries. Participants reported a range of 1 to 400 visits to health care professionals for DDH care across 1 to 66 years. Lack of information and resources on treatment practicalities and timelines, along with emotional burden of diagnosis, were greatest challenges reported. Conclusion: Results demonstrate that DDH diagnosis and treatment can pose significant burden on patients and caregivers. Reliable public information is needed to support those affected. Global educational efforts are needed to raise awareness of DDH risk factors, signs, and symptoms among care providers, to increase awareness and improve identification, screening, and monitoring of at-risk children.

Purpose Imaging the carotid arteries at 7T ideally requires a flexible multichannel array that allows B1-shimming and conforms to different neck sizes. The major challenge is to minimize coupling between closely spaced coils and to make the coupling relatively insensitive to loading conditions. Methods We have designed a five-channel flexible transceive array composed of shielded-coaxial-cable coils placed on the anterior part of the neck and conforming to the anatomy. In vivo imaging of the carotid arteries in three subjects has been performed. Results The measured noise correlation matrices show the decoupling level between the individual elements to be -12.5 dB and better. Anatomical localizer imaging of the carotids shows both carotids in every subject well visualized after B1-shimming. In vivo black-blood, carotid images were acquired with very high in-plane spatial resolution (0.25 × 0.25 mm2 ) with clear depiction of the vessel walls. Conclusions The flexibility of the proposed coil has been demonstrated by imaging subjects with different neck circumferences. To the best of our knowledge, the in-plane resolution of 0.25 × 0.25 mm2 is the highest reported at 7T.

In 2015, the Lancet Commission on Global Surgery published six global surgery goals, one of which was to provide 80% of the world’s population with timely access to the Bellwether Surgical procedures. Little is known about the prevalence or efficacy of subsequent interventions implemented in under-resourced countries to increase timely access to Bellwether surgical procedures. A systematic review of articles and grey literature published in MEDLINE, Embase, Cochrane, CINAHL, and Web of Science databases was conducted. Two independent reviewers evaluated 1923 captured abstracts using explicit inclusion and exclusion criteria. Following a thematic analysis, two reviewers conducted data extraction on the eleven manuscripts included in the final review. The studied innovations, sparse in number, centred on improved educational resources, the development of orthopaedic devices, and models for assessing surgical access disparity. Eight papers were centred around timely access to caesarean sections, three around open fracture reduction, and three around laparotomy; all focused on adult populations. Five papers addressed innovations in West Africa, two in East Africa, two in South Asia, and one in Southeast Asia. Common outcome metrics were not used to assess improvements to timely surgical access. Few published interventions have been implemented since the publication of the 2015 Lancet Commission on Global Surgery goals that have or will longitudinally increase the availability of timely surgical access in Low and Middle-Income Countries (LMIC). Tangible outcome measures in existing literature are lacking. An up-scaling and wider adoption of successful strategies is necessary and possible.

Background Global neurosurgery operates at the intersection of neurosurgery and public health. Although most global neurosurgery initiatives have targeted neurosurgeons and trainees, medical students represent the future of global neurosurgery. Methods A narrative review of the literature regarding research methodology, education, economics, health policy, health advocacy, relevant to global neurosurgery was conducted. Results We summarize pearls that all medical students interested in global neurosurgery should know. Discussion To become effective agents of change within global neurosurgery, medical students must master competencies of motivation, organization, collaborativeness, dependability, flexibility, resilience, creative problem-solving, ethical thinking, cultural humility, and global awareness and gain knowledge and skills regarding research, education, policy making, and advocacy. Discussions with neurosurgeons and trainees, neurosurgery interest groups, conferences, university global neurosurgery initiatives, and student organizations represent opportunities for learning and becoming involved in global neurosurgery.

Background Profiling the entire genome at base pair resolution in a single test offers novel insights into disease by means of dissection of genetic contributors to phenotypic features. Methods We performed genome sequencing for a patient who presented with atypical hereditary sensory and autonomic neuropathy, severe epileptic encephalopathy, global developmental delay, and growth hormone deficiency. Results Assessment of the variants detected by mapped sequencing reads followed by Sanger confirmation revealed that the proband is a compound heterozygote for rare variants within RETREG1 (FAM134B), a gene associated with a recessive form of hereditary sensory and autonomic neuropathy, but not with epileptic encephalopathy or global developmental delay. Further analysis of the data also revealed a heterozygous missense variant in DNM1L, a gene previously implicated in an autosomal dominant encephalopathy, epilepsy, and global developmental delay and confirmed by Sanger sequencing to be a de novo variant not present in parental genomes. Conclusions Our findings emphasize the importance of genome‐wide sequencing in patients with a well‐characterized genetic disease with atypical presentation. This approach reduces the potential for misdiagnoses.

Western life style, and high calorie diet in particular is causing major health problems such as insulin resistance, hepatic steatosis and heart disease in the modern age. High fat diet (HFD) induces similar changes in mice, such as increased body weight, hypercholesterolemia and accumulation of triglycerides in the liver. These changes can be ameliorated by the administration of some Lactobacillus species. The focus of this study was to analyze the fatty acid content of liver, heart and brain tissues of mice fed HFD and administered with either Lactobacillus plantarum WCFS1 or Lactobacillus rhamnosus LA68, and to analyze the fatty acid content of these organs after a two months washout period. The fatty acid composition of mouse liver tissue changed significantly due to probiotic administration during a 12 weeks HFD regime and active Lactobacillus administration had a slightly reversing effect toward the standard mouse diet group, but after the washout period these changes disappeared. The fatty acid composition of the heart and brain tissues was significantly changed in the HFD regime but probiotic administration had no significant influence on the fatty acid profile of these two organs. Upon the 8 weeks washout period the only remaining beneficial effect was the significantly lower mouse weight in the supplemented groups compared to the HFD group.

Citation Zivkovic I, Stojanovic M, Petrusic V, Inic-Kanada A, Dimitrijevic L. Induction of APS after TTd hyper-immunization has a different outcome in BALB/c and C57BL/6 mice. Am J Reprod Immunol 2011; 65: 492–502 Problem The antiphospholipid syndrome (APS) is a systemic autoimmune disease characterized by vascular thrombosis and/or pregnancy complications (lower fecundity and lower litter size), as well as by an increase in anti-β2 glycoprotein I (β2GPI)-specific autoantibody titer. We have investigated how the genetic background of the immune system [T helper (Th) prevalence] and the type of animal model of APS influence the induced pathology. Method of Study Antiphospholipid syndrome induced by tetanus toxoid (TTd) hyper-immunization and by intravenous application of monoclonal anti-β2GPI-specific antibody 26 was compared in C57BL/6 (Th1 prone) and BALB/c (Th2 prone) mice. Results Tetanus toxoid hyper-immunization of BALB/c mice led to reduction in fertility, but in C57BL/6 mice a decrease in fecundity occurred. In both cases, pathology was caused by anti-β2GPI antibodies, the production of which was adjuvant and strain dependent. Conclusion We conclude that TTd immunization and i.v. application of monoclonal antibody 26 induced the same reproductive pathology and that the type of pathology is strain dependent.

Results are presented concerning our attempts to create a suitable model system for studying the connection between microbial antigen (micAg), autoimmunity and autoimmune disease on the basis of hyper-immunization and application of micAg in different contexts. Our research was focused on tetanus toxoid (TTd) as a model micAg. Non-pretreated and complete Freund's adjuvant pretreated BALB/c mice were immunized with high doses of TTd mixed with glycerol or aluminum hydroxide as adjuvants. The main aims of the experiments were to evaluate the properties of induced humoral immune responses, evaluate the pathological potential of induced immune responses and determine possible correlations between the properties of a humoral immune response and its pathological potential. The production of TTd-specific and self-reactive beta(2)-glycoprotein I (beta(2)-GP I)-specific antibodies (Abs) was detected in all groups but with specific, context-related properties. Analysis of pregnancy-related pathology (anti-beta(2)-GP I Abs-associated) showed differences in the pathological potential of the induced immune response. It was demonstrated that severity of pathology is positively correlated to the abundance of IgG that recognizes beta(2)-GP I adsorbed onto phosphatidylserine, and to IgG affinity. Furthermore, it was demonstrated that molecular mimicry, which results in generation of anti-beta(2)-GP I Abs upon TTd immunization, is necessary but not sufficient for the development of pregnancy-related pathology.

A murine monoclonal IgG1 antibody, marked as MAb26, specific for tetanus toxoid has been immunochemically characterized. By performing en- zyme-linked immunosorbent assays (ELISAs) and western blot analyses, it was demonstrated that MAb26 reacted with tetanus toxoid, tetanus toxin and β2-gly- coprotein I (β2GPI). According to the results, MAb26 recognized the sequential epitope on the tetanus heavy chain. The affinity constant, calculated from Scat- chard plots of MAb26 binding to tetanus toxoid, was 1.145×10 8 M -1 and the measurement of the relative affinity of MAb26 by ELISA using thiocyanate elution showed a significantly higher affinity of MAb26 to the toxoid (p = = 0.0012) in comparison to the toxin. Additionally, the reactivity of MAb26 toward the toxoid forms increased when the tetanus toxin was detoxified using 8 mM and higher formaldehyde concentrations. The similarity of the tetanus toxoid to several sera proteins, either at the level of its conformation (IL-1α) or at the level of peptide sequences (β2GPI, laminin) favors its role in auto- immunity by the mechanism of molecular mimicry. As the induction of an au- toimmune disease is dependent on the breakdown of tolerance, which could be the result of an overt hyperstimulation, the control of the presence and concen- tration of self-reactive epitopes in vaccine preparations is a prerequisite. In this study, it was shown that MAb26 can: 1) discriminate between the tetanus toxin and different toxoid forms, which makes it a good candidate for antibody con- trol during vaccine preparation; 2) due to its cross-reactivity with β2GPI, it could provide information on the presence of a potentially dangerous sequential epi- tope expressed at the protein surface.

PROBLEM Studies on experimental antiphospholipid syndrome (APS) models proved that molecular mimicry between plasma protein beta(2)-glycoprotein I (beta(2)GPI) and structure within micro-organisms or their products, might be a cause for experimental APS. Considering the heterogeneity of polyclonal antiphospholipid antibodies (aPLs), it is important to define the precise characteristics of pathogenic aPLs. To avoid the influence of polyclonality and to further analyse the connection between molecular mimicry and APS, we produced monoclonal antibodies (MAbs) against tetanus toxoid (TTd) and tested their reactivity against beta(2)GPI. METHOD OF STUDY In this report, we analysed the characteristics of MAb26 raised against TTd and cross-reactive with beta(2)GPI: its binding properties in various in vitro immunoassays, its specific interactions with surface epitopes expressed on apoptotic cells and its role in vivo. RESULTS We have demonstrated that MAb26: (i) binds beta(2)GPI being immobilized on an appropriate surface: irradiated polystyrene plates, non-irradiated plates pre-coated with anionic phospholipids and polyvinylidene fluoride membrane; (ii) binds specifically to apoptotic but not to viable cells and the binding is beta(2)GPI-dependent; and (iii) induces a pathologic pregnancy outcome when passively injected into BALB/c mice. CONCLUSION This study concluded that certain subpopulations of antibodies raised against TTd and cross-reactive with beta(2)GPI, because of the molecular mimicry mechanism, could have pathologic potential.

Group I grass pollen allergens are major contributors to grass pollen-related seasonal allergic rhinitis, and as such a primary target for allergen specific immunotherapy. In this study the potential therapeutic role of oral application of Lactobacillus plantarum WCFS1, directing cell wall attachment of the recombinant Fes p1 allergen, from Festuca pratensis was tested in a mouse model of Fes p1 allergy. For surface expression of Fes p1 allergen in L. plantarum WCFS1 pSIP system with inducible expression was used. Balb/c mice were sensitized with Fes p1 protein in alum and subsequently received live recombinant L. plantarum orally. Antibody levels (IgE, total IgG, IgG1, IgG2a, and IgA) were determined by ELISA. Differential eosinophil count in peripheral blood was performed. Reduced peripheral blood eosinophilia and increased serum IgG2A levels was detected in both groups which received live L. plantarum orally. Specific serum IgA levels were increased only in mice treated with the recombinant bacteria. Oral application of L. plantarum WCFS1 has a beneficial therapeutic effect in a mouse model of Fes p1 allergy. Cell surface expression of Fes p1 allergen potentiates this phenomenon in an allergen specific way. (C) 2015 Elsevier B.V. All rights reserved.

In this study, two Lactobacillus strains (L. rhamnosus LA68 and L. plantarum WCFS1) were evaluated for their effects on high fat diet induced pathology in mice. The aim was to determine whether the administration of lactic acid bacteria had beneficial effects on ameliorating pathology. C57BL/6 mice fed a high fat diet were orally administered with the Lactobacillus strains. Both the metabolic and immunological parameters were analyzed. The administration of both of the strains had beneficial effects on mouse weight, serum cholesterol, TNF-alpha levels and liver histology. LA68 lowered the total cholesterol and HDL levels more prominently, whereas WCFS1 was more potent in lowering the TG and LDL levels. Leptin and adiponectin levels were increased in all experimental groups to different extents. The administration of L. plantarum WCFS1 led to a marked increase in leptin levels, as well as an increase in CD3+CD4+ and CD3+CD8+ cells, and a decrease of CD25+ cells, and had a lowering effect on IL-6 production and cell metabolic activity. In conclusion, active administration of both Lactobacillus strains had a positive effect on HFD-induced pathology. Although both of the tested strains had beneficial effects, oral administration of WCFS1 increased leptin levels and had a more prominent immunomodulatory effect, which should be taken into consideration in case of humane usage.

The aim of this study was to investigate the effects of centrally applied somatostatin-28 on morphometric characteristics of the thymus, the thymocyte subpopulations, as well as, on apoptosis and phases of cell cycle in thymocytes. For this purpose, peripubertal male rats were cannulated intracerebroventriculary and treated with repeated, nanomolar concentrations of somatostatin-28 (experimental group) or saline (control group). Animals were sacrificed and their thymuses were used for the analysis of thymocyte subpopulations, cell cycle and apoptosis by flow cytometry and for the evaluation of morphometric parameters by stereological analysis. Our results showed that somatostatin-28 caused decrease of the thymic mass and volume, as well as total thymocytes number. Stereological analysis revealed volume decrease of thymic cortex and medulla accompanied with cellularity decrease. Somatostatin in the deeper cortex decreased the number of thymocytes, per volume unit, while in outer cortex raised their number. A significant increase in the percentage of double-negative and both single-positive thymocyte subpopulations, in parallel with a diminished percentage of double-positive cells was found. The cellularity of double-positive and single-positive thymocyte subpopulations was decreased. Somatostatin-28 treatment augmented the percentage of apoptotic cells, while the percentage of the cells represented in phases of cell cycle was reduced. These results suggest that somatostatin-28 induce thymus hypotrophy as result of decreasing cortex and medulla volume and cellularity. Changes in the percentage and cellularity of thymocyte subpopulations and numerical density of thymocytes in outer and deeper cortex, indicate that somatostatin-28 evoked disturbance in transition of double-negative to double-positive thymocytes.

Recent reports suggest that the metabolic activity of the enteric microbiota may influence the fatty acid composition of the host tissue. There are many studies dealing with the influence of lactobacilli on various pathological conditions, and some of the effects are strain-specific. This study was designed to test the effects of a particular Lactobacillus strain, Lactobacillus rhamnosus LA68 on fatty acid composition of the liver and the brain of C57BL/6 mice in the absence of an underlying pathological condition. Female mice were supplemented with live L. rhamnosus LA68 bacteria for the duration of 1 month. Serum biochemistry was analyzed and liver and brain fatty acid composition was assessed by gas-liquid chromatography. Significant changes in liver and brain fatty acid composition were detected. In the liver tissue we detected an increase in palmitoleic acid (p = 0.038), while in the brain compartment we found an increase in palmitic (p = 0.042), stearic (p = 0.017), arachidonic acid (p = 0.009) and docosahexaenoic acid (p = 0.004) for control versus experimental group. These results show discrete changes caused by LA68 strain consumption. Even short duration of administration of LA68 influences the fatty acid composition of the host which adds to the existing knowledge about Lactobacillus host interaction, and adds to the growing knowledge of metabolic intervention possibilities.

Probiotic bacteria have been used in human nutrition for centuries and are now attracting more attention. In order to examine the immunological aspects of probiotic consumption,Lactobacillus rhamnosusLA68 was orally administrated using gavage to healthy C57BL/6 mice. After one month splenocytes were isolated, and analysed by flow cytometry. The magnitude of splenocyte proliferation upon stimulation with lipopolysaccharide and peptidoglycan and cytokine levels (IFN-γ, IL-6, IL-10 and IL-17) was assessed. Cytokine levels in the serum were also analysed. Oral application of strain LA68 leads to a significant decrease of CD3+, CD25+ and CD19+ cells, and an increase of CD11b+ and CD16/CD32+ positive cell populations in the mouse spleen. Increased sensitivity to stimulation through proliferation and IL-6 secretion was detected. Increased serum IFN-γ and decreased IL-10 levels were found. Our results show increased responsiveness of splenocytes, activation of the Th1 type of immune response, and a shift of leucocyte populations towards monocyte/granulocyte populations.

To investigate the differences between thymocytes development in vivo and in vitro, thymus lobe fragments from 12-weeks old male Albino Oxford rats were cultivated over a 7-days period. In the controls and cultivated thymic lobes fragments were evaluated and the viability, apoptosis and cell cycle of thymocytes, as well as the histological characteristics of thymic tissue. Additionally, we analyzed the expression of CD4, CD8 and TCRαβ on thymocytes by flow cytometry. The obtained results showed that thymus cellularity decreased during cultivated time due to expanded apoptosis, decreased proliferation and the absence of progenitors reseeding thymus. The relative proportion of thymocyte subsets in the first 24 hours of culture remained similar as in the control. However, cultivation for 3 and 7 days modulated the relative proportions between thymoctye subsets. The percentage of DP TCRαβlow increased, DP TCRαβhi subset remained unchanged, both SP TCRαβhi subsets decreased while the same mature SP phenotype dominated in culture media. These results demonstrate that cultivated thymic fragments retain the capacity for T cell development, although cultivation modulates this process. Sa namerom da ispitamo razlike između in vivo i in vitro sazrevanja timocita gajili smo fragmente lobusa timusa poreklom od mužjaka Albino Oksford pacova, starih dvanaest nedelja, u vremenskom periodu od sedam dana. Nakon kultivacije određivani su vijabilnost, apoptoza i ćelijski ciklus timocita, kao i histološke osobine timusnog tkiva. Takođe je analizirano ispoljavanje markera diferentovanja CD4, CD8 and TCRαβ na površini timocita metodom tečne citofluorometrije. Dobijeni rezultati su ukazali da sedmodnevna kultivacija dovodi do smanjenja broja ćelija u timusu usled povećane apoptoze, smanjene proliferacije i odsustva ulaska progenitora timocita. Tokom prvih 24 sata kultivacije ne dolazi do promena u odnosima timocitnih populacija. Međutim, duže vreme kultivacije - 3 i 7 dana moduliše relativne odnose između timocitnih subpopulacija - povećava se procenat DP TCRαβlow, procenat DP TCRαβhi timocita ostaje nepromenjen, dok su procenti ćelija oba subseta SP TCRαβhi smanjeni, mada je prisustvo pomenutih SP subsetova dominantno u medijumu za kultivaciju. Navedeni rezultati pokazuju da kultivisani fragmenti timusnog tkiva zadržavaju sposobnost da podrže sazrevanje timocita u jednostruko pozitivne T ćelije, mada je diferentovanje timocita donekle modulisano kultivacijom.

We have already demonstrated (Stojanovic et al., 2009) a connection between tetanus toxoid (TTd) hyperimmunization and the induction of anti-phospholipid syndrome (APS) in BALB/c mice. Here we show that C57BL/6 mice subjected to an identical procedure do not exhibit any like pathology attributable to anti-phospholipid antibodies; we explain that this absence results from idiotypic connectivity. Six groups of C57BL/6 mice were hyperimmunized with TTd in aluminum hydroxide or glycerol, with or without pretreatments. Pretreated mice had been injected with polyclonal or nonspecific immune stimulators, such as complete Freund's adjuvant (CFA) or glycerol. The epitope specificity of induced antibodies was tested by indirect ELISA using a tetanus toxoid immunogen and these autoantigens: phospholipids, gangliosides, laminin. Idiotypic connectivity was tested by competitive ELISA and gauged from the degree to which the interaction of idiotypic/anti-idiotypic complementary antibodies was inhibited in the presence of immunized sera antibodies. Higher idiotypic connectivity was noted amongst pretreated mice. There was a positive correlation between higher connectivity and autoantibody levels that acted to favor the participation of natural autoantibodies in the inhibitory process. We conclude that idiotypic connectivity plays a protective role in immunization-induced autoimmunity.

Lectins are widely used in many types of assay but some lectins such as banana lectin (BanLec) are recognised as potent immunostimulators Although BanLec's structure and binding characteristics are now familiar, its immunostimulatory potential has not yet been fully explored The synthesis by recombinant technology of a BanLec isoform (rBanLec) whose binding properties are similar to its natural counterpart has made it possible to overcome the twin problems of natural BanLec's microheterogeneity and low availability This study's aim is to explore the immunostimulatory potential of rBanLec in the murine model Analyses of the responses of Balb/c- and C57 BL/6-originated splenocytes to in vitro rBanLec stimulation were performed to examine the dependency of rBanLec's immunostimulatory potential upon the splenocytes' genetic background It is shown that the responses of Balb/c- and C57 BL/6-originated splenocytes to rBanLec stimulation differ both qualitatively and in intensity. The hallmarks of the induced responses are T lymphocyte proliferation and intensive interferon-gamma secretion Both phenomena are more marked in Balb/c-originated cultures; Balb/c-originated lymphocytes produce interleukin (IL)-4 and IL-10 following rBanLec stimulation Out results demonstrate that any responses to rBanLec stimulation are highly dependent upon genetic background. they suggest that genetic background must be an important consideration in any further investigations using animal models or when exploring rBanLec's potential human applications (C) 2009 Elsevier B V. All rights reserved

According to the recommendation of the World Health Organization (WHO), the use of an in vivo test for measuring of the potency of tetanus toxoid vaccine (TTdV) is still unavoidable, but the establishment of a convenient in vitro test would significantly improve the work in this field. A sandwich enzyme-linked immunosorbent assay (sELISA) was developed for a rapid and sensitive quantification of tetanus toxoid (TTd). We produced four monoclonal antibodies (MAbs) designated 41, 51, 62, and 71 that reacted with TTd and recognized, different antigenic determinants on TTd. We also used two of these antibodies for developing a sELISA, with MoAb 71 as an immobilized and MoAb 51 as a capture antibody. The measurement range of this assay was from 31-1000 ng/mL and the minimum detection limit for TTd was 31 ng/mL. This high sensitivity of this sELISA and its good reproducibility suggest that the developed method could be reliably used to estimate the concentration of TTd, which could be easily extrapolated to the estimation of vaccine potency.

In this paper we report on the generation of Abs possessing specificities similar to those of Abs used in immunization, and on the generation of Id and anti-Id specificities in the sera of mice immunized with commensal bacterial antigens.The human monoclonal antibody IgM DJ (VH3/VL2) expresses natural antibody properties, natural idiotope (Y7), and specificity towards Lactic acid bacteria (LAB). When used in immunization it generates LAB-specific antibodies. Immunization with LAB, as detected in the presence of biotin-labelled mouse monoclonal anti-idiotopic antibodies Y7 and IgM DJ generates Abs1 and Abs2, respectively. These findings may imply that the recognition of bacterial motifs accords with the rules of idiotypic network theory. This theory, first proposed by Jerne in 1974 and often overlooked since, has been subject to change during the course of immunological research. Recent experiments concerning the recognition of bacterial motifs and natural memory in the immune system have inspired us in our attempt at explaining the possible role of natural Id in immune memory.

In this paper we report data regarding the IgM Y7 cross-reactive idiotope (CRIo) obtained by analysis of: 1) its V-gene subgroup dependance, 2) the frequency of its expression on human monoclonal IgMs and IgM molecules from normal and pathological sera. Furthermore, comparison of epitopic repertoire and nature of binding of human monoclonal IgMs expressing Y7 CRIo was performed to confirm the natural antibody properties of these molecules. IgM isolated from sera of patient DJ (IgM DJ) which expresses the Y7 idiotope has been classified to V(H)3/V(L)2 subgroup. From ten IgMs tested only IgM from patient RD (IgM RD) has been shown to express Y7 idiotope. Y7(+) human IgMs bound to ssDNA, lactic acid bacteria, mouse laminin, porcine thyroglobulin and mouse IgG. Higher percentage of the expression of Y7 CRIo was detected in the sera of patients suffering from autoimmune diseases such as lupus, rheumatoid arthritis and psoriasis vulgaris as well as in patients suffering from chronic infections of the lower urinary tract. Antigen binding repertoire and properties of Y7(+) monoclonal IgM, frequency of Y7 expression on monoclonal IgMs and its concentration in normal and pathological sera indicate the important biological role of this CRIo within the immune system.