Nucleases in immunity. I. The effect of immunization on RNase and DNase activity in lymphoid tissues

The level of RNase and DNase in the spleen, lymph nodes and thymus glands of mice immunized with sheep erythrocytes was determined. Within 12 hr after immunization there was a moderate decrease in the level of specific RNase activity in the spleen. The depression persisted for several days and then returned to normal. The level of DNase activity also decreased in the spleen of immunized animals, returning to near normal levels on day 4 to 5 and increasing moderately by day 6 and 8.

RNase activity in the lymph nodes and thymus increased rapidly after immunization, reaching a peak level several fold higher than in control animals on days 2 and 6. The level of DNase activity in lymph nodes and thymus was also elevated during the first few days after immunization, but to a lesser extent. The changes in total enzyme activity generally preceded the appearance of haemolytic plaque forming cells. Most of the antibody forming cells were present in the spleen, with peak numbers at day 4. Much fewer antibody forming cells were present in the lymph nodes, and even fewer in the thymus. The relationship between immunogenesis and nucleic acid metabolism in lymphoid tissue was discussed.

     

1141635485Genetic stress (IL-10 deficiency) and toxicant (PCB)-induced disruption of pregnancy

Several epidemiologic studies have provided evidence that a significant number of pregnant women living within the World Trade Center disaster area experienced a high rate of low birth weight and premature deliveries. Our hypothesis is that these women were predisposed to pregnancy disruption effects of toxicants detected in the dust of the disaster area. We sought to examine the effects of PCB on pregnancy outcome in an IL-10^-/- mouse model. IL-10^-/- or congenic wild type mice of 6–8 weeks age were given i.p injections of Aroclor 1254 (PCB) at doses of 50 or 500 μg/mouse in 100 μL corn oil on gestational day (gd) 1 and 7 or an equivalent (100 μL) amount of corn oil. Mice were sacrificed on gd 13 and uteri and spleen were excised and collected. Uterine mononuclear cells (UMC) and splenic mononuclear cells (SMC) were isolated. These cell populations were subjected to phenotypic and functional characterization. A portion of uterine tissue was either snap frozen for placental PCB contents or for histology. No doses of Aroclor 1254 affected the pregnancy outcome in wild type mice. However, IL-10^-/- mice experienced fetal resorption when injected with high dose (500 μg/mouse) of Aroclor 1254. Local immune dysregulation and placental anomalies including apoptosis and immunocyte infiltration are currently being investigated. Our results strongly suggest that IL-10 deficiency and PCB-mediated immunotoxicity lead to adverse pregnancy outcomes.
Acknowledgement:  Supported by NIEHS Superfund Basic Research Program Award P42ES13660.     

Phagocytic cell killing mediated by secreted cytotoxic factors of Vibrio cholerae

Vibrio cholerae strain VB1 secretes a number of enzymes into the outside medium that utilize ATP as a substrate. Such enzymes are found in the outside medium during the mid-log phase of growth, when the optical density at 650 nm is about 0.4, and they demonstrate nucleoside diphosphate kinase (Ndk), 5' nucleotidase, and adenylate kinase (Ak) activities. We report that the filtered growth medium of V. cholerae, as well as the flowthrough fraction of a green Sepharose column during fractionation of the growth medium, had very little cytotoxicity by itself towards macrophages and mast cells but exhibited significant cytotoxicity in the presence of exogenous ATP. Such fractions, harboring 5' nucleotidase, Ndk, and presumably other ATP-utilizing enzymes, demonstrated enhanced macrophage and mast cell death; periodate-oxidized-ATP (oATP)-treated macrophage and mast cells or such cells exposed to 0.1 mM Mg(2+), where surface-associated P2Z receptors could not be activated, were not susceptible to subsequent ATP addition. Microscopic visualization of mast cells clearly demonstrated cell morphological changes such as swelling, vacuolization, and nuclear fragmentation following treatment with ATP and the growth medium of V. cholerae; however, these effects were suppressed if the mast cells were pretreated with oATP. These results strongly imply that the secreted ATP-utilizing enzymes of V. cholerae modulate the external ATP levels of the macrophage and mast cells, leading to their accelerated death, presumably through activation of P2Z receptors. Thus, development of inhibitors for such enzymes may reduce the level of V. cholerae infection; alternatively, mutations in such genes may eliminate V. cholerae survival in the gut and contribute to a safer live vaccine.     

Relationship of staphylococcal toxins and enzymes with serological and phage types

A study has been made of 523 strains of staphylococci on the basis of biological properties, phage typing, and serology. The value of serology in the identification of pathogenic staphylococci has been assessed.     

Pathophysiological manifestations in mice exposed to anthrax lethal toxin

Pathophysiological changes associated with anthrax lethal toxin included loss of plasma proteins, decreased platelet count, slower clotting times, fibrin deposits in tissue sections, and gross and histopathological evidence of hemorrhage. These findings suggest that blood vessel leakage and hemorrhage lead to disseminating intravascular coagulation and/or circulatory shock as an underlying pathophysiological mechanism.     

颅眶沟通性脑膜瘤14例

1临床资料经病理检查证实为颅眶沟通性脑膜瘤的14(男5,女9)例患者,年龄12～68岁,病程1～5 a.临床表现主要有头痛、突眼、视力减退、眼球运动受限、视乳头水肿,首发症状为头痛者8例,突眼者4例,视力减退者2例;肿瘤大小: 颅内>眶内10例,眶内>颅内4例.     

Alder–Reilly Anomaly in Hurler’s Syndrome in a Neonate: A Rare Case Report

A 22-days-old male newborn baby presented with persistence of neonatal jaundice since birth. On clinical examination he had coarse facial features, a prominent forehead, enlarged tongue, icterus, hepatosplenomegaly, skeletal deformities and bilateral inguinal hernia. On investigation the peripheral smear revealed Alder–Reilly anomaly in the neutrophils suggesting mucopolysaccharidosis. Mucopolysaccharide excretion spot test of the urine was positive; and an assay for glycosaminoglycans in the urine was also high, which confirmed the clinical diagnosis of Hurler’s syndrome. We present this rare case to highlight the association of Alder–Reilly anomaly and bilateral inguinal hernia in Hurler’s syndrome even in neonates.     

Prevalence of celiac disease in an urban area of Brazil with predominantly European ancestry

AIM: To determine the prevalence of celiac disease in a group of volunteer blood donors at a blood bank in the city of Curitiba, Brazil through detection of the serum marker immunoglobulin A (IgA) antitransglutaminase antibody.METHODS: Blood samples collected from 2086 healthy and Hemotherapy in Curitiba were submitted to ELISA testing for the IgA antitransglutaminase antibody.Positive samples received IgA antiendomysium antibody test through indirect immunofluorescence using human umbilical cord as substrate. Subsequently, patients who were positive on both tests underwent small bowel (distal duodenum) biopsy.RESULTS: Six subjects, four males and two females,tested positive for the two serum markers. Five of the six were submitted to intestinal biopsy (one declined the procedure). Biopsy results revealed changes in the distal duodenum mucosa (three classified as Marsh Ⅲb lesions and two as Marsh Ⅱ lesions). Most donors diagnosed having celiac disease presented multiple symptoms (gastrointestinal tract complaints). One donor reported having a family history of celiac disease (in a niece).CONCLUSION: Among apparently healthy blood donors,the prevalence of biopsy-confirmed celiac disease was approximately 1:417, similar to that seen in European countries.     

Inhibitory effect of 1-O (2 methoxy) hexadecyl glycerol and phenylbutyrate on the malignant properties of human prostate cancer cells

The ability of the naturally occurring ether lipid, 1-O (2 methoxy) hexadecyl glycerol (MHG), and phenylbutyrate (BP) to inhibit cellular proliferation, anchorage-independent growth and cellular invasion in the human prostate cancer LnCap and DU145 cells was determined. Both MHG and PB inhibited the malignant properties of these prostate cancer cells. The concentrations required to achieve similar inhibitory effect, however, were significantly different for these two agents. MHG inhibited cell growth with equal potency in these cell lines with an IC-50 value of 93 μM for LnCap, and 97 μM for DU145. The IC-50 values for PB were 1.3 mM and 7.3 mM, respectively, for LnCap and DU145 cells. Both MHG and PB (IC-50 concentrations) inhibited the anchorage-independent growth and cellular invasion in these cells. Over 50% inhibition of anchorage-independent growth was achieved for both LnCap and DU145 cells by PB, while a lesser degree of inhibition was achieved with MHG. Both MHG- and PB-treated cells showed a reduced propensity to invade matrigels. Invasion of PB-treated LnCap and DU145 cells was reduced, respectively, by approximate 41 and 30% when compared to untreated control cells, while invasion of MHG-treated LnCap and DU145 cells was reduced to a lesser extent. Because differentiation-inducing agents may possess chemopreventive properties, the use of naturally occurring MHG and nontoxic PB in the chemoprevention of malignant diseases warrants further investigation. This revised version was published online in July 2006 with corrections to the Cover Date.