The development of bone mineral lateralization in the arms.

UNLABELLED: Bone mineral content (BMC) is known to be greater in the dominant arm after the age of 8 years. We studied a group of children and found that BMC sidedness gradually increased up to the age of 6 years and then remained stable into late adolescence. INTRODUCTION: Bone mineral content (BMC) exhibits sidedness in the arms after the age of 8 years, but it is not known whether BMC is greater in the dominant arm from birth or whether lateralization develops in early childhood. To address this, we examined bone mineral status in relation to handedness and age. METHODS: Subjects (N = 158) were children recently initiating glucocorticoids for underlying disease (leukemia 43 %, rheumatic conditions 39 %, nephrotic syndrome 18 %). Handedness was determined by questionnaire and BMC by dual-energy X-ray absorptiometry. RESULTS: Median age was 7.2 years (range, 1.5 to 17.0 years), 49 % was male, and the spine BMD Z-score was -0.9 (SD, 1.3). By linear regression, BMC sidedness in the arms was significantly related to age (r = 0.294, p = 0.0005). Breakpoint analysis revealed two lines with a knot at 6.0 years (95 % CI, 4.5-7.5 years). The formula for the first line was: dominant:nondominant arm BMC ratio = 0.029 × age [in years] + 0.850 (r = 0.323, p = 0.017). The slope of the second line was not different from 0 (p = 0.332), while the slopes for the two lines were significantly different (p = 0.027). CONCLUSIONS: These results show that arm BMC sidedness in this patient group develops up to age 6 years and then remains stable into late adolescence. This temporal profile is consistent with mechanical stimulation of the skeleton in response to asymmetrical muscle use as handedness becomes manifest.

Short- and long-term outcome of linear morphoea in children.

BACKGROUND: Linear morphoea (LM) is a rare fibrosing disorder of the limbs or the face that may cause functional disability and severe aesthetic sequelae. Despite a wide range of therapeutics reported for LM, there is currently a lack of consensus on the optimal therapy. Little is known about the long-term outcome of this disease. OBJECTIVES: To describe the short- and long-term outcome of a large series of patients with LM acquired in childhood. METHODS: A retrospective chart review of 52 paediatric patients with LM seen in our centre during a 20-year span (1990-2010) and a telephone survey in 2011 to assess the long-term outcome of these patients. RESULTS: Limbs were affected twice as often as the face, with a higher proportion of female patients. Stabilization was obtained after a mean disease duration of 5·4 years. Patients sometimes experienced long stretches of disease quiescence followed by reactivation; 31% of patients reported active disease after 10 years. All but one patient had aesthetic sequelae, and 38% had functional limitations. The effectiveness of methotrexate and systemic corticosteroids was apparent in the short term. CONCLUSIONS: LM needs prolonged monitoring as the disease can have very long periods of quiescence followed by reactivation. The combination of methotrexate and systemic corticosteroids was effective in the early stages of the disease but did not seem to prevent long-standing active disease or relapse in the long term.

Immunologic and enzymatic studies of two breeding lines of NZB mice that differ in chromosome breakage.

Two sublines of NZB/BI mice were developed by selective matings according to chromosome breakage frequencies. These sublines--HB, a line with high chromosome breakages, and LB, a line with low or normal breakage rates--were studied in regard to the age of the animals as it related to two different aspects. The first aspect was immunologic: A decreased response to T-cell mitogens was found in old NZB mice, but this response was more pronounced in HB mice. The response to the B-cell mitogen (lipopolysaccharide) was increased in both sublines as compared to that in BALB/c mice. The percentages of IgG-positive and theta-positive spleen cells were evaluated in both sublines: Some increase in IgG-positive cells was observed in the spleens of 2- to 8-month-old NZB mice and a slight decrease was seen after age 8 months. The percentage of theta-positive cells diminished according to the age of the mice, and the decrease occurred earlier in HB than in LB mice. The second aspect studied was enzymatic and concerned the levels of DNA alpha- and beta-polymerases and terminal DNA nucleotidyltransferase in the thymuses and spleens of these animals. The major finding noted was an augmentation of 100-200% in the terminal DNA nucleotidyltransferase levels in HB thymuses by comparison with LB thymuses. The levels of both polymerases were increased in spleen cells of HB mice as compared to those of LB mice.

Circulating immune complexes in sera of hamsters bearing simian virus 40-induced tumours.

Reported previously in certain human carcinomas and rat and mouse experimental tumor systems, circulating immune complexes (IC) have now been detected in Syrian hamsters bearing tumors produced by injection with syngeneic TSV5Cl2 cells. IC were detected by the Raji cell radioimmune assay, adapted for use in hamster sera. A novel feature of this test is the use of a stable covalently linked hamster immunoglobulin G aggregate as the reaction standard. Stable over six months on storage at -70 degrees and showing no tendency to form precipitates on thawing or during test procedures, this preparation greatly facilitated quantitation of hamster IC by Raji cells. Seven of 19 sera of hamsters bearing SV40-induced tumors from 60 to 128 days had IC concentrations exceeding 40 microgram aggregated hamster immunoglobulin G equivalents per ml, as contrasted to IC levels of less than 25 microgram for 19 age-matched normal hamsters. There appeared to be no significant correlation between IC levels and tumor weight or duration of tumor within the hamster host. The results suggest a complex relationship between IC and a number of factors connected with tumor growth.

Isolation of two immunoglobulin G subclasses, IgG2 and IgG1, from hamster serum using protein A-sepharose.

The isolation of hamster immunoglobulin classes and subclasses by affinity chromatography on protein A and selective elution was studied using 0.1 M phosphate buffer, pH 8. The IgG fraction was completely absorbed, while IgM did not bind. Sequential application of buffers of decreasing pH allowed the elution of pure IgG2 (eluted at pH 6) and IgG1 (eluted at pH 5). Both subclasses were fully recovered. IgG2 could be subfractionated into 2 peaks eluted respectively at pH 6.5 and 6. Immunodiffusion of the whole IgG2 fraction against anti-hamster immunoglobulin serum gave 2 precipitation lines. One of these lines was missing in the pH 6.5 fraction. Until now only 2 IgG subclasses have been described and these results suggest heterogeneity of hamster IgG2.

Spleen cell populations in normal and tumor-bearing hamsters.

Spleen cell subpopulations from normal and tumor-bearing hamsters (TBH) were quantified using Petri dishes coated with specific antibodies, and by flow cytometric immunofluorescence analysis. The relative numbers of T cells (Thy + cells) decreased, by both methods, as a function of tumor growth, while the number of B cells (bearing surface Ig) increased. Cells without T or B markers (null cells) were more numerous in the spleen of TBH and a large number of them expressed the receptor for the Fc fragment of IgG. Splenic cells were also sorted according to their light-scattering properties, and electron microscopic analysis was performed on the sorted fractions. It showed the presence of secreting plasmocytes and activated macrophages in the spleen of TBH.

Nude Syrian hamsters: some immunological and histological characteristics.

Nude mutants appeared in our colony of Syrian hamsters. They were hairless and just had rudiments of thymus. Only 3.5% of splenic cells were killed by rabbit anti-hamster thymocytes serum + C' whereas 55.5% of these cells were lyzed by an anti-hamster IgG + C' and 60-70% fixed the fluorescent protein A, but could not respond either to B-cell mitogens or to rat cell mitogens. The natural cytotoxic activity of the spleen cells from nude hamsters was evaluated in comparison with the same activity expressed by spleen cells of golden Syrian hamsters.

Induction of simian virus 40 transplantation immunity in hamsters by gel-purified SV40 large T antigen.

Simian virus 40 (SV40) large T antigen and p53 cellular protein were isolated from an SV40-transformed hamster cell line by immunoprecipitation with anti-T sera and purified by sodium dodecyl sulfate-gel electrophoresis. These two protein were tested in hamsters for the presence of SV40 transplantation rejection antigenic sites by in vivo transplantation rejection assay. The large T antigen immunized the hamsters against a challenge of SV40 tumor cells and the protected animals generated cytotoxic spleen cells. Hamsters immunized with the p53 cellular protein were not protected against SV40-induced tumor but there was some delay in the appearance of tumor.

Evolution of DNA polymerase alpha, beta and terminal deoxynucleotidyl transferase in hamster lymphoid populations during the development of different types of tumors.

We followed the evolution of DNA polymerase alpha, beta and terminal deoxynucleotidyl transferase (TdT) in the thymus, spleen and bone marrow of tumor bearing hamsters. Tumors were induced by spontaneously transformed fibroblasts (EHB), by SV40 (ZD) or by 20-methylcholanthrene (MCH2) transformed fibroblasts. We have shown that, in the thymus, the TdT activity of the various tumor bearing hamsters is generally inferior to the TdT activity of the control. In the spleen of animals bearing viral or spontaneously induced (ZD or EHB) tumors, the TdT activities were higher than in the controls. Moreover, DNA polymerase alpha and DNA polymerase beta activities in the spleen of the EHB tumor bearing hamsters were higher than in the controls. This fact, however, was not observed in the two other kinds of tumor, possibly because EHB tumors were growing much faster and led to earlier changes in DNA polymerases activities, as well as in spleen size and cellular populations. Finally, in the bone marrow, TdT, polymerase alpha and beta of ZD and EHB tumor bearers reached much higher activities than in the controls; for the MCH2 tumor bearing hamsters, no difference with the controls could be observed.

[Differences in the fixation of antibodies in presence or absence of complement on SV40 transformed cells (author's transl)]. / Comparaison de la fixation d'anticorps en présence ou en absence de complément sur des cellules transformées par SV 40.

The fixation of antibodies directed against viral induced antigens was observed on SV40 transformed hamster fibroblasts. These cells were incubated for various periods of time with sera of tumor bearing hamster in the presence or absence of fresh guinea pig complement. The fixation of antibodies was revealed by an anti hamster immunoglobulins immune serum labeled with 125 iodine. Autoradiographic observations were made by optic and electron microscopy. The fixation of antibodies is quite different in the presence or in the absence of complement. Cells incubated with antibodies alone show a regular label on the plasma membrane with no decrease in the total cell population as compared to the controls. When the complement is added, one fraction of the cells is heavily labeled detached and progressively destroyed. Some of the cells (2/10) still attached on the flask are heavily labeled on the plasma membrane, the major part being nearly negative.

Prevalent vertebral fractures among children initiating glucocorticoid therapy for the treatment of rheumatic disorders.

OBJECTIVE: Vertebral fractures are an under-recognized problem in children with inflammatory disorders. We studied spine health among 134 children (87 girls) with rheumatic conditions (median age 10 years) within 30 days of initiating glucocorticoid therapy. METHODS: Children were categorized as follows: juvenile dermatomyositis (n = 30), juvenile idiopathic arthritis (n = 28), systemic lupus erythematosus and related conditions (n = 26), systemic arthritis (n = 22), systemic vasculitis (n = 16), and other conditions (n = 12). Thoracolumbar spine radiograph and dual x-ray absorptiometry for lumbar spine (L-spine) areal bone mineral density (BMD) were performed within 30 days of glucocorticoid initiation. Genant semiquantitative grading was used for vertebral morphometry. Second metacarpal morphometry was carried out on a hand radiograph. Clinical factors including disease and physical activity, calcium and vitamin D intake, cumulative glucocorticoid dose, underlying diagnosis, L-spine BMD Z score, and back pain were analyzed for association with vertebral fracture. RESULTS: Thirteen vertebral fractures were noted in 9 children (7%). Of these, 6 patients had a single vertebral fracture and 3 had 2-3 fractures. Fractures were clustered in the mid-thoracic region (69%). Three vertebral fractures (23%) were moderate (grade 2); the others were mild (grade 1). For the entire cohort, mean +/- SD L-spine BMD Z score was significantly different from zero (-0.55 +/- 1.2, P < 0.001) despite a mean height Z score that was similar to the healthy average (0.02 +/- 1.0, P = 0.825). Back pain was highly associated with increased odds for fracture (odds ratio 10.6 [95% confidence interval 2.1-53.8], P = 0.004). CONCLUSION: In pediatric rheumatic conditions, vertebral fractures can be present prior to prolonged glucocorticoid exposure.

Humoral and cellular immune response during the growth of an SV40 induced tumour in hamsters.

Hamster fibroblasts transformed in vivo by the SV40 virus (TSV5Cl2) induce tumours when injected into adult hamsters and antibodies present in sera of tumour-bearing animals are used to demonstrate the presence of the antigens specific for the viral transformation. These tumours are a very useful tool in studying the evolution of the immune response during the tumour growth. A systematic histological examination of the spleen, thymus and lymph nodes was undertaken and the results thus obtained were correlated with a parallel study of the cells of the peritumoral region, the thymus and the spleen by immunofluorescence using antisera of different specificities. We were able to show that the plasma cells which make up the early peritumoral reaction and the lymphoblasts found later in spleen and thymus both synthesize antibodies directed against virus induced antigens. Circulating antibody directed against the same antigens is first detected at/or about the time that the peritumoral plasma cell reaction disappears and increases progressively as tumour weight increases.

[Neoantigens on cells transformed by SV40. IV. - A quantitative study of antigenic sites in a cell line (TSV5C12) (author's transl)]. / Néo-antigenes des cellules transformées par le virus SV40. IV. - Etude quantitative des sites antigéniques d'une lignée cellulaire (TSV5C12)

The antigenic sites at the membrane of SV40-transformed hamster fibroblasts (TSV5C12) were studied using isotope techniques. A specific fixation of antibodies directed against SV40 coded antigen had previously been shown using a cytotoxicity test in presence of fresh guinea pig complement. Using the "paired-label" technique, described by Boone et al., approximatively 7.2. 10(7) fixing site for the specific antibodies against SV40 coded antigen(s), were found. The fixation of antibodies onto the cells varied with the time of culture of cells. It was not possible to determine whether the number of antigenic sites, or their accessibility to the antibodies, or their susceptibility to complement, was dependent on the cell cycle.

Cyclophosphamide induction of splenic suppressor cells in hamsters.

Injection of hamsters with a single sublethal dose of cyclophosphamide induced splenic atrophy followed by considerable hypertrophy. During the splenomegaly phase, the in vitro reactivity of spleen cells to concanavalin A (ConA) or protein A (ProtA) was decreased. The spleens of 6-8-month old animals contained cells able to suppress the in vitro reactivity of normal lymphocytes to ConA or ProtA. These cells were absent in 2-month old animals, and some suppressor activity could be shown in 3-month old hamsters. Suppressor activity was abolished by removal of adherent cells and by silica treatment, but antisera against thymocytes or IgG were ineffective.

Immunological and clinical differences between juvenile and adult onset of systemic lupus erythematosus.

INTRODUCTION: Systemic lupus erythematosus (SLE) in children usually follows a more severe course than in adults, but sometimes in the previous studies reported there are many confounding factors. OBJECTIVE: To analyse the immunological and clinical characteristics of SLE juvenile onset and SLE adult onset. METHODS: We studied 179 patients with SLE, 49 patients were aged 6-18 yrs at onset of disease. Anti-dsDNA antibodies were detected by radioimmunoassay and antibodies to extractable nuclear antigens (ENA): anti-nRNP, anti-Sm, anti-Ro/SS-A and anti-La/SS-B antibodies by ELISA, counterimmuno-electrophoresis and immunoblotting. RESULTS: Juvenile-onset SLE shows a higher frequency of cutaneous vasculitis (44.8% vs 27.6%; P < 0.05), seizures (18.3% vs 7.6%; P < 0.05) nephropathy (67.3% vs 48.4%; P < 0.025), and discoid lupus erythematosus (26.5% vs 13.8%; P < 0.05). The incidence of articular manifestations is lower than in adults (85.7% vs 96.1%; P < 0.025). No significant differences were found between the two groups in relation with the prevalence of antinuclear antibodies. CONCLUSIONS: Juvenile-onset SLE has more frequent neurological and renal manifestations than adult-onset SLE, but immunological markers are similar in both groups. These features suggest the most severe clinical manifestations in the juvenile-onset SLE group are not related with the presence of studied antibodies by different methods.

[Demonstration of antigen-antibody complex of TSV5C12 cell membranes by means of guinea pig fluorescent anti-complement antibodies]. / Mise en évidence du complexe antigène-anticorps sur la membrane des cellules TSV5Cl2 à l'aide d'anticorps fluorescents anti-complément de cobaye

The application of rabbit anti-guinea pig complement fluorescent antibody to SV40 transformed cells demonstrated the presence of immune complexes on the cell membrane surface. The presence of such complexes was not detectable by using fluorescent rabbit anti-hamster immunoglobulins antisera.

[Cellular and humoral response to tumor antigens in the hamster]. / Réponse cellulaire et humorale aux antigènes tumoraux chez le hamster

Studies on the histological of the lympoid organs and the evolution of the immune response were done during the growth of a tumour induced by SV40 transformed cells. The immune response was characterized by a high level of circulating antibodies and presence in the thymus and spleen of lymphoid cells containing IgG with antibody function.