Variants of lymphoid lines produced with ricin A-chain monoclonal antibody conjugates

Conjugates of ricin A-chain with monoclonal anti-light chain antibodies specifically killed cells hearing kappa or lambda immunoglobulin (Ig) light chains. Exposure of cells from B-lymphoblastoid cell lines (B-LCL) to conjugate for less than 30 h had only a slight effect on cell growth, but on 48 h exposure a marked killing effect was achieved. After recovery of growth, cells were re-exposed to conjugate for 9-14 days. Treatment of cells from the EB4 line (sIgG lambda) in this way yielded 4 variants which showed a marked reduction in levels of surface Ig lambda and secreted Ig lambda with slight, or no, reduction in MHC class II expression and similar growth rates to the parent line. Variant lines retained their phenotype over long periods of culture.     

The release of adenosine triphosphate from frog skeletal muscle in vitro

1. Active frog sartorius muscle in vitro liberates a substance into the bathing solution which has a pronounced stimulatory action on the frog heart.2. The stimulatory effect is not due to an increase in the K(+) concentration of the bathing solution, nor is it due to the liberation of catecholamines.3. In a molecular sieve chromatography procedure the stimulatory substance can be eluted in a single fraction which shows a maximum absorption of U.V. light at a wave-length of 265 nm, indicative of the presence of substances containing a purine ring.4. Low concentrations (10(-7)-10(-8) g/ml.) of adenosine triphosphate (ATP), adenosine diphosphate (ADP) and uridine triphosphate (UTP) have a marked stimulatory action on the frog heart. The action of ATP and ADP on the heart is qualitatively very similar to that of the muscle bathing solution, while the action of UTP is distinctly different. The triphosphates of inosine, cytidine and guanosine stimulate the heart when in high concentration only. Adenosine and adenosine monophosphate do not stimulate the heart.5. Incubation of the muscle bathing solution and of solutions of ATP with the enzyme apyrase for the same time produces a similar marked reduction in the stimulatory action of both on the heart. Apyrase catalyses the break-down of nucleotide triphosphates to monophosphates.6. The elution behaviour of the stimulatory substance determined by molecular sieve chromatography is the same as that for ATP.7. The muscle bathing solution causes light to be emitted from firefly lantern extract, the pattern of light emission being similar to that produced by nucleotide triphosphates.8. The concentrations of ATP having the same quantitative action on the frog heart and on firefly extract as a given muscle bathing solution are almost identical, whereas the matching concentrations of ADP and UTP in the two methods of assay are widely different.9. It is concluded that ATP is released from active frog skeletal muscle in vitro. This release may play an important part in the reactive hyperaemia of muscular exercise since ATP has a powerful vasodilator action.     

Heterologous radioimmunossay of monkey alpha-fetoprotein.

Immunoelectrophoresis showed that rabbit anti-human alpha-fetoprotein (AFP) cross-reacts with monkey AFP which was not detectable in the serum from an adult non-pregnant monkey. A heterologous radioimmunoassay of monkey AFP was developed using this antiserum which circumvented the need for purified monkey AFP. The radioimmunoassay is of sufficient sensitivity to measure AFP in maternal and fetal serum and amniotic fluid in the rhesus monkey.     

Expression of superoxide dismutase and xanthine oxidase in myometrium, fetal membranes and placenta during normal human pregnancy and parturition

Superoxide, an agent which attenuates the half-life of nitric oxide, is metabolized and synthesized by superoxide dismutase (SOD) and xanthine oxidase, respectively. Over the last few years much work has focused on the role of nitric oxide in human parturition. The aim of this study was to determine whether the onset of human parturition is associated with a change in the expression of copper/zinc superoxide dismutase (Cu/Zn SOD), manganese superoxide dismutase (Mn SOD) or xanthine oxidase within the uterus. Samples of myometrium, placenta, decidua and fetal membranes were obtained from women before and after the onset of labour at term. Immunocytochemistry was used to localize Cu/Zn SOD, Mn SOD and xanthine oxidase and measure SOD enzyme activity. Cu/Zn and Mn SOD-like immunoreactivity was detected in syncytiotrophoblast cells, villous stromal cells and endothelial cells of blood vessels in the placenta. In the myometrium Cu/Zn and Mn SOD were localized to myocytes and endothelial cells and to some vascular smooth muscle cells. In the fetal membranes we observed staining for Cu/Zn SOD and Mn SOD in the amnion, chorion, extravillous trophoblast and decidua. There was no difference in SOD enzyme activity or staining intensity for SOD between different cell types before and during labour. Xanthine oxidase immunoreactivity was identified in each of the tissues examined and again there was no difference in immunostaining in tissues obtained from women delivered before or after the onset of labour. These results show that the pregnant uterus is capable of both synthesizing and degrading superoxide and suggest that superoxide dismutase and xanthine oxidase may play a role in the maintenance of uterine quiescence during pregnancy, but not in the initiation of parturition.      

Effect of modified alpha 2macroglobulin on leucocyte locomotion and chemotaxis.

The effects of human alpha 2macroglobulin (alpha 2M) on locomotion of human neutrophils and monocytes in micropore filter assays in vitro were studied. Native alpha 2M had no effect on cell locomotion. In contrast, alpha 2M which had been modified by interaction with proteases (trypsin, collagenase), or with ammonium sulphate, stimulated locomotion of both cell types. The degree of locomotory response induced in the cells by alpha 2M correlated closely with changes in molecular conformation of alpha 2M as estimated by measurements of binding of the fluorescent probe, 1-anilinonaphthalene-8-sulphonic acid (ANS). However neutrophil locomotion stimulated by modified alpha 2M appeared to be solely chemokinetic, whereas monocytes showed both chemokinetic and chemotactic responses to modified alpha 2M. The reason for this difference in response between the two cell types is unclear, but it is reflected in the lack of specific binding of alpha 2M-protease complexes by neutrophils. Earlier workers had shown specific binding of such complexes by mononuclear phagocytes.     

Hydrosalpinges adversely affect markers of endometrial receptivity

While in-vitro fertilization (IVF) was initially developed in women with tubal factor infertility, recent clinical studies have suggested that the presence of hydrosalpinges lowers implantation and pregnancy rates. We postulated that these hydrosalpinges cause impaired endometrial receptivity. A total of 103 women with hydrosalpinges were prospectively evaluated, and compared with 55 infertile and 44 fertile controls. All women had endometrial biopsies during the window of implantation, analysed by conventional histological criteria, and also stained for three integrin markers of endometrial receptivity (alpha1beta1, alpha4beta1 and alpha vbeta3). Women with hydrosalpinges (cases) expressed significantly less of the alpha vbeta3 integrin compared with controls. There was no difference in expression of alpha1beta1 or alpha4beta1 among groups. A significantly greater number of cases had out of phase histology and missing alpha vbeta3 (type I defects) and absent integrin expression despite normal histological maturation (type II) defects, compared with controls. Of 20 women with impaired endometrial receptivity who were also biopsied after hydrosalpinx surgery, 70% demonstrated increased alpha vbeta3 expression. Seventy-seven percent of type I and 57% of type II defects were corrected postoperatively. Using markers of endometrial receptivity, this study demonstrates that inflammatory hydrosalpinges have an adverse effect on endometrial receptivity, which in some cases may be overcome by surgical treatment of the hydrosalpinx.      

Constitutive retinal CD200 expression regulates resident microglia and activation state of inflammatory cells during experimental autoimmune uveoretinitis

Recent evidence supports the notion that tissue OX2 (CD200) constitutively provides down-regulatory signals to myeloid-lineage cells via CD200-receptor (CD200R). Thus, mice lacking CD200 (CD200(-/-)) show increased susceptibility to and accelerated onset of tissue-specific autoimmunity. In the retina there is extensive expression of CD200 on neurons and retinal vascular endothelium. We show here that retinal microglia in CD200(-/-) mice display normal morphology, but unlike microglia from wild-type CD200(+/+) mice are present in increased numbers and most significantly, express inducible nitric oxide synthase (NOS2), a macrophage activation marker. Onset and severity of uveitogenic peptide (1-20) of interphotoreceptor retinoid-binding protein-induced experimental autoimmune uveoretinitis is accelerated in CD200(-/-) mice and although tissue destruction appears no greater than seen in CD200(+/+) mice, there is continued increased ganglion and photoreceptor cell apoptosis. Myeloid cell infiltrate was increased in CD200(-/-) mice during experimental autoimmune uveoretinitis, although NOS2 expression was not heightened. The results indicate that the CD200:CD200R axis regulates retinal microglial activation. In CD200(-/-) mice the release of suppression of tonic macrophage activation, supported by increased NOS2 expression in the CD200(-/-) steady state accelerates disease onset but without any demonstration of increased target organ/tissue destruction.     

<Emphasis Type="Italic">TCF7L2</Emphasis>variant genotypes and type 2 diabetes risk in Brazil: significant association,but not a significant tool for risk stratification in the general population

Background  

Genetic polymorphisms of the TCF7L2 gene are strongly associated with large increments in type 2 diabetes risk in different populations worldwide. In this study, we aimed to confirm the effect of the TCF7L2 polymorphism rs7903146 on diabetes risk in a Brazilian population and to assess the use of this genetic marker in improving diabetes risk prediction in the general population.     

CD34+ corneal stromal cells are bone marrow-derived and express hemopoietic stem cell markers

Previous studies have suggested that corneal stromal keratocytes express the CD34 antigen. We wished to investigate CD34 antigen expression in normal mouse cornea using dual- and triple-staining techniques. Whole-mount preparations of mouse and rat corneas were examined with confocal microscopy using single, dual, or triple immunostaining to study their morphology, phenotype, and distribution. Single-cell suspensions from normal mouse corneas were also prepared and analyzed by flow cytometry. After short-term culture of corneal stromal explants, nonadherent cells were harvested and cytospins were prepared and stained for different markers.Combined staining for F-actin and leukocyte differentiation markers clearly showed that the corneal stroma contains a population of CD45(+) resident bone marrow-derived cells, whereas most cells were CD45-F-actin(+) keratocytes. A significant proportion (two thirds) of CD45(+) cells in the normal corneal stroma expressed CD34(+), whereas no CD45(-) cells (i.e., keratocytes) coexpressed CD34. In addition, CD34(+) cells were CD11c(-) and CD11b(+). Fewer than 10% of the CD34(+) cells also coexpressed Sca-1(+), but no CD34(+) cells coexpressed major histocompatibility complex (MHC) class II(+). In contrast, the remaining population of CD45(+)CD34(-) cells in the corneal stroma expressed CD11b, MHC class II(+) but not CD11c and were found mostly in the anterior and peripheral part of stroma. These cells are in intimate contact with corneal keratocytes, which stained only for F-actin and were negative for all leukocyte markers. Very few CD45(+) cells expressed the B220 marker, suggesting a plasmacytoid dendritic cell phenotype. Flow cytometry analyses confirmed the morphometric data showing that 68% of CD45(+) cells coexpress CD34 and CD11b, whereas 22% are CD11b(+)CD34(-).We conclude that the normal mouse cornea contains two populations of bone marrow-derived leukocytes, both of which are distinct from stromal keratocytes. The larger population resembles CD34(+) hemopoietic stem cells, whereas the smaller population are CD34(-)CD11b(+) MHC class II(+) macrophages. A very small percentage comprises plasmacytoid dendritic cells.     

Reliability of the acetabular teardrop as a landmark

Summary This study investigated the effect of tilt and observer reliability on radiographic measurements of the position of a prosthetic acetabular cup in seven dry bone pelves using the teardrop as a landmark. Coronal or sagittal tilt of more than five degrees was easily recognisable and there was effectively no observer variation in the measurements up to this limit. In addition, 90 out of 100 randomly selected antero-posterior pelvic radiographs from an outpatient department were not significantly rotated and 93 demonstrated a clearly defined teardrop. Measurements about the teardrop on routine radiographs are therefore sufficiently accurate to allow assessment of prosthetic position.

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La valeur du sourcil cotyloidien comme repère d'analyse radiologique

Résumé Cette étude, conduite sur 7 bassins secs, apprécie l'effet de l'inclinaison du bassin sur la qualité de l'analyse radiographique de la position d'une cupule prothétique de hanche en utilisant le sourcil cotyloïdien comme repère. Une inclinaison du bassin dans les plans coronal et sagittal est aisément détectable et il n'existe pas de variation d'analyse entre les différents observateurs en dessous de 5° d'inclinaison. De plus, sur 100 radiographies antéro-postérieures de bassin choisies au hasard dans les dossiers de consultation, 90 avaient été réalisées sans incidence particulièrement adaptée et l'on pouvait repérer facilement le sourcil sur 93% d'entre elles. Les mesures faites sur des radios de routine sont donc suffisamment précises pour permettre l'évaluation de la position d'une prothèse à partir du sourcil cotyloïdien.