Ontogeny of B-lymphocyte function. III. In vivo and in vitro studies on the ease of tolerance induction in B lymphocytes from fetal, neonatal, and adult mice

The ease of tolerance induction in B lymphocytes from fetal, neonatal, and adult mice was studied in vivo, in a cell transfer system, and in vitro. Three different tolerogens were used: ultracentrifuged BGG, DNP(6)-D-GL, and ultracentrifuged DNP(22)-BGG. Irradiated thymectomized mice were reconstituted with B cells from fetal or neonatal liver or adult spleen or bone marrow. The mice were injected with tolerogen 1 day later. They were given normal thymus cells and challenged with either BGG or DNP(44)-BGG between 4 and 14 days after tolerance induction. With BGG no difference in ease of B-cell tolerance induction was observed in mice reconstituted with B cells from 17-day fetal liver, neonatal liver, 8- day-old spleen, adult spleen, or adult bone marrow. B cells from 14-day fetal donors are relatively resistant to tolerance induction. In contrast, with DNP(6)-D-GL and DNP(22)-BGG B cells from neonatal donors were clearly more susceptible to tolerance induction than were B cells from adult donors. Comparable results were obtained in studies on tolerance induction in vitro. Neonatal B cells were more susceptible than adult B cells to tolerance induction upon culture with DNP(6)-D-GL or DNP(22)-BGG. However, neonatal and adult B cells were identical with respect to ease of tolerance induction in vitro with deaggregated BGG. The results suggest that there are multiple mechanisms for B-cell tolerance induction. Immature B cells appear to be more susceptible to tolerance induction by some mechanisms but not by others. It is suggested that immature B cells are more susceptible to tolerance induction with moderately polyvalent antigens such as hapten-carrier conjugates. With antigens like BGG which do not haverepeated epitopes no difference between mature and fetal B cells in regard to ease of tolerance induction is observed. These observations raise questions about the importance of relative ease of tolerance induction in immature B cells as a mechanism controlling the normal induction of self tolerance.     

Cellular infiltration and cytokine mRNA expression in perennial allergic rhinitis

BACKGROUND: Allergen challenge in allergic rhinitis patients leads to local eosinophilia and Th2-type cytokine expression. Natural exposure to grass pollen is additionally characterized by epithelial mast-cell infiltration. We hypothesized that perennial allergic rhinitis is also associated with T-cell and eosinophil infiltration of the nasal mucosa, local Th2-type cytokine expression, and increased numbers of nasal epithelial mast cells. METHODS: Nasal biopsies from perennial allergic rhinitis patients and controls were analysed by immunocytochemistry for different cell populations and in situ hybridization for cytokine mRNA-expressing cells. RESULTS: Perennial allergic rhinitis was associated with increased numbers of submucosal CD3+ T cells (P=0.05), EG2+ activated eosinophils (P=0.01), and CD68+ macrophages (P=0.01) compared to controls. Epithelial, but not submucosal, tryptase-positive mast cells were also elevated in rhinitics compared to controls (P=0.01). The numbers of cells expressing interleukin (IL)-5 were higher (P=0.01) and the numbers of cells expressing IL-2 were lower (P=0.04) in rhinitic patients than controls. There were no significant differences for either IL-4 or interferon-gamma between the groups. CONCLUSIONS: Perennial allergic rhinitis is characterized by mast-cell migration into the epithelium; submucosal infiltration by T cells, eosinophils, and macrophages; and an imbalance in local T-cell cytokine production in favour of enhanced IL-5 and reduced IL-2 expression.     

Extradural cavernous haemangioma simulating a disc protrusion

Cavernous haemangiomas confined to the epidural space are rare and are therefore infrequently considered in the differential diagnosis of spinal epidural masses. In order to draw attention to this diagnosis, a case in which an epidural cavernous haemangioma simulates a lateral/foraminal disc protrusion is presented.     

A randomized, controlled trial of nurse home visiting to vulnerable families with newborns

OBJECTIVE: This project aimed to evaluate the impact of a home visiting programme that targeted families where the child, for environmental reasons, was at great risk of poor health and developmental outcomes. METHODOLOGY: Women in the immediate postpartum period were recruited to a randomized double-blind controlled trial on the basis of self-reported vulnerability factors and were randomly assigned to receive either a structured programme of nurse home visiting, supported by a social worker and paediatrician (n = 90), or assigned to a comparison group receiving standard community child health services (n = 91). Parenting stress and maternal depression were measured at enrollment and at 6 weeks. Preventive health behaviour, service satisfaction and home environment outcomes were tested at 6 weeks, as were child health outcomes. RESULTS: At six weeks, women receiving the home-based programme had significant reductions in postnatal depression screening scores as well as improvements in their experience of the parental role and improvement in the ability to maintain their own identity. Maternal-infant interactions were more likely to be positive, with significantly higher (better) scores in aspects of the home environment related to optimal development in children, particularly maternal-infant secure attachment. Intervention group mothers were significantly more satisfied with the community child health service. CONCLUSIONS: This form of intervention for families is effective in promoting secure maternal-infant attachment, preventing maternal mood disorder and is welcomed by the families receiving it. These findings may predict long-term benefits for the healthy development of children otherwise at risk of a range of poor health and development outcomes.     

cis-Retinoic acid stimulates the clonal growth of some myeloid leukemia cells in vitro

We studied the effects of cis-retinoic acid (cisRA) on the clonogenic growth of samples of leukemic cells from 35 patients with acute nonlymphocytic leukemia (ANLL). We observed significant inhibition of leukemic colony growth in 17 samples by 10(-7) to 10(-6)M cisRA. However, we found that retinoid exposure resulted in striking stimulation of clonal growth in ten samples at the same drug concentrations. With the exception of cases with promyelocytic features, there was no morphologic or functional evidence that cisRA induced the leukemic blasts to differentiate. Both inhibition and stimulation were dose-dependent and observable at pharmacologically achievable levels of cisRA. Leukemic cells with monocytic features more frequently demonstrated a stimulatory response than did those without monocytic features. Depletion of T lymphocytes and monocytes did not alter the type of growth response. Assays for cellular retinoic acid- binding protein (CRABP) were performed on five samples (two with inhibitory growth responses, two with stimulatory responses, and one with no growth) and failed to reveal detectable levels of CRABP in any case. The addition of cisRA to liquid suspensions of leukemic cells produced no significant change in the number of viable cells. We conclude that the effects of cisRA on leukemic colony growth are not cytotoxic and not mediated by T lymphocytes, monocytes, or CRABP. More importantly, cisRA appears to enhance the growth of certain human leukemia cells in vitro. Taking into account the increasing use of retinoids in clinical trials for patients with leukemia, the latter findings may represent a significant cautionary note.     

Proton magnetic resonance spectroscopy in the brain: report of AAPM MR Task Group #9

AAPM Magnetic Resonance Task Group #9 on proton magnetic resonance spectroscopy (MRS) in the brain was formed to provide a reference document for acquiring and processing proton (1H) MRS acquired from brain tissue. MRS is becoming a common adjunct to magnetic resonance imaging (MRI), especially for the differential diagnosis of tumors in the brain. Even though MR imaging is an offshoot of MR spectroscopy, clinical medical physicists familiar with MRI may not be familiar with many of the common practical issues regarding MRS. Numerous research laboratories perform in vivo MRS on other magnetic nuclei, such as 31P, 13C, and 19F. However, most commercial MR scanners are generally only capable of spectroscopy using the signals from protons. Therefore this paper is of limited scope, giving an overview of technical issues that are important to clinical proton MRS, discussing some common clinical MRS problems, and suggesting how they might be resolved. Some fundamental issues covered in this paper are common to many forms of magnetic resonance spectroscopy and are written as an introduction for the reader to these methods. These topics include shimming, eddy currents, spatial localization, solvent saturation, and post-processing methods. The document also provides an extensive review of the literature to guide the practicing medical physicist to resources that may be useful for dealing with issues not covered in the current article.     

Leïomyosarcome de la prostate: Neoplasie rare

The prostatic leïomyosarcoma is a very uncommon tumor of the adult. It is often diagnosed to an advanced stage, because of the clinical and radiological non specificity. Its prognosis is very dark.The objective of our study is to illustrate the important role of the imagering, represented by the CT and especially the MRI in the balance of extension and the post-therapeutic follow-up of this tumor.We report a 49 years old patient's observation, allowed for unrests mictionnels evolving since 6 months in a context of change of the general state. To the clinical exam, the prostate was increased of volume and nodular. A radiological balance made of US, CT and abdomino-pelvic MRI has been achieved. It showed an heterogeneous prostate, infiltrating the grease of neighborhood and the ureteral meats, with important bilateral urétéro-hydronephrosis of uphill. One also noted the presence of suspected hepatic nodules. A trans-perineal prostatic biopsy has been achieved, concluded to a prostatic leïomyosarcoma. Because of the bad general state and the importance of the local extension and from afar of the prostatic tumor, a trans-ureteral resection has been achieved, associated to a chemotherapy. The evolving have been marked by the patient's death after his second cure of chemotherapy.The CT and especially the MRI had a primordial role in the balance of local extension and from afar of the prostatic léïomyosarcoma and the only means to affirm the diagnosis is the histology completed by an immuno-histochimical study. Their therapeutic handling is not codified at the present time and their prognosis remained very dark.