Natural Clostridium botulinum type C toxicosis in a group of cats

Clinical signs of botulism were observed in a group of eight cats, four of which died, after being fed pelican carrion. Clostridium botulinum type C was isolated from one cat. The microorganism and its toxin were found in the pelican. This is apparently the first report of natural botulism in cats.     

Mild Brachmann–de Lange syndrome: Changes of phenotype with age

We present a girl with mild manifestations of the Brachmann-de Lange syndrome (BDLS) with gradual change of the phenotype. Her findings support the hypothosis of variability of the phenotypic spectrum of the disorder.     

Expression of the chemokine receptors CCR4, CCR5, and CXCR3 by human tissue-infiltrating lymphocytes.

Differential expression of adhesion molecules and chemokine receptors has been useful for identification of peripheral blood memory lymphocyte subsets with distinct tissue and microenvironmental tropisms. Expression of CCR4 by circulating memory CD4(+) lymphocytes is associated with cutaneous and other systemic populations while expression of CCR9 is associated with a small intestine-homing subset. CCR5 and CXCR3 are also expressed by discrete memory CD4(+) populations in blood, as well as by tissue-infiltrating lymphocytes from a number of sites. To characterize the similarities and differences among tissue-infiltrating lymphocytes, and to shed light on the specialization of lymphocyte subsets that mediate inflammation and immune surveillance in particular tissues, we have examined the expression of CCR4, CXCR3, and CCR5 on CD4(+) lymphocytes directly isolated from a wide variety of normal and inflamed tissues. Extra-lymphoid tissues contained only memory lymphocytes, many of which were activated (CD69(+)). As predicted by classical studies, skin lymphocytes were enriched in CLA expression whereas intestinal lymphocytes were enriched in alpha(4)beta(7) expression. CCR4 was expressed at high levels by skin-infiltrating lymphocytes, at lower levels by lung and synovial fluid lymphocytes, but never by intestinal lymphocytes. Only the high CCR4 levels characteristic of skin lymphocytes were associated with robust chemotactic and adhesive responses to TARC, consistent with a selective role for CCR4 in skin lymphocyte homing. In contrast, CXCR3 and CCR5 were present on the majority of lymphocytes from each non-lymphoid tissue examined, suggesting that these receptors are unlikely to determine tissue specificity, but rather, may play a wider role in tissue inflammation.     

Defects in regulation of apoptosis in caspase-2-deficient mice

During embryonic development, a large number of cells die naturally to shape the new organism. Members of the caspase family of proteases are essential intracellular death effectors. Herein, we generated caspase-2-deficient mice to evaluate the requirement for this enzyme in various paradigms of apoptosis. Excess numbers of germ cells were endowed in ovaries of mutant mice and the oocytes were found to be resistant to cell death following exposure to chemotherapeutic drugs. Apoptosis mediated by granzyme B and perforin was defective in caspase-2-deficient B lymphoblasts. In contrast, cell death of motor neurons during development was accelerated in caspase-2-deficient mice. In addition, caspase-2-deficient sympathetic neurons underwent apoptosis more effectively than wild-type neurons when deprived of NGF. Thus, caspase-2 acts both as a positive and negative cell death effector, depending upon cell lineage and stage of development.     

Antibody to Mycoplasma pneumoniae in Nasal Secretions and Sputa of Experimentally Infected Human Volunteers

After experimental infection with Mycoplasma pneumoniae, 42% of 67 volunteers developed a threefold or greater rise in antibody in nasal secretions as measured by radioimmunoprecipitation. Development of an antibody increase in sputum was detected more often, i.e., in 73% of the volunteers. Each of the antibody increases involved immunoglobulin (Ig) A. Twelve rises in IgG antibody were detected in the specimens which exhibited a rise in IgA antibody. In almost every instance the rise in IgA antibody exceeded that seen with IgG antibody. Analysis of the response to experimental challenge with M. pneumoniae of volunteers with different levels of preexisting respiratory tract IgA antibody suggested that this secretory antibody was related to host resistance to M. pneumoniae disease. Further, respiratory tract IgA antibody appeared to be more directly related to host resistance than was antibody in serum.     

Differences in lectin binding of malignant pleural mesothelioma and adenocarcinoma of the lung.

In order to differentiate between malignant pleural mesothelioma and adenocarcinoma of the lung, the glycoconjugate profiles of 6 reactive mesothelial lesions, 23 mesotheliomas (17 epithelial, 1 desmoplastic, 2 biphasic, and 3 fibrous types), and 28 well-differentiated pulmonary adenocarcinomas were evaluated with the use of 8 lectins in addition to anti-carcinoembryonic, anti-keratin and anti-epithelial membrane antigen. Formalin-fixed, paraffin-embedded tissues were stained with the avidin-biotin peroxidase complex method. Reactions of wheat germ (WGA) and peanut (PNA) agglutinin with neuraminidase treatment lectins were positive in 5 of 6 (83%) and 3 of 6 (50%) cases, respectively, in reactive mesothelial lesions. Thirteen of 23 (57%) malignant mesotheliomas of the pleura showed a positive reaction for WGA and PNA with neuraminidase treatment; other lectins were low-positive, below 9%. In contrast, pulmonary adenocarcinomas showed positive reactions in 27 of 28 cases (96%) for PNA, 26 of 28 (93%) for Ricinus communis (RCA-I), 25 of 28 (89%) for WGA, and 22 of 28 (79%) for succinylated WGA (SucWGA). The findings suggest that malignant pleural mesothelioma and pulmonary adenocarcinoma have consistent and distinct glycoconjugate profiles, and that stains for RCA-I and SucWGA may be useful for differential diagnosis.     

Microtiter solid-phase radioimmunoassay for detection of Escherichia coli heat-labile enterotoxin.

The development of a microtiter solid-phase radioimmunoassay for the detection of Vibrio cholerae enterotoxin and heat-labile Escherichia coli enterotoxin is described. The test is based on the immunological similarity between V. cholerae toxin and E. coli heat-labile toxin. The assay is easy to perform, quantitative, and at least as sensitive and specific as the Y-1 adrenal cell system.     

A blood-borne antigen induces rapid T-B cell contact: a potential mechanism for tolerance induction

Understanding the difference between the development of a productive T‐cell response and tolerance is central to discerning how the immune system functions. Intravenous injection of soluble protein is thought to mimic the presentation of self‐serum and orally introduced antigens. It is generally toleragenic. The current view is that this outcome reflects the failure of ‘immunogenic’ dendritic cells to relocate to the T‐cell zone of the secondary lymphoid tissues. Here, using a peptide/I‐E^k tetramer and antibodies to stain splenic sections, we showed that antigen‐specific T cells were activated in the spleen within hours of injection or feeding of protein. The activated T cells were found to be located at the T–B junction, the bridging zone and the B‐cell area, interacting directly with B cells. In addition, B cells gain the ability to present antigen. Our results suggest a way for T cells to be stimulated by blood‐borne antigen presented by naïve B cells, a potential mechanism of tolerance induction.     

Effect of heterogeneity and assumed mode of inheritance on lod scores.

Heterogeneity is a major factor in many common, complex diseases and can confound linkage analysis. Using computer-simulated heterogeneous data we tested what effect unlinked families have on a linkage analysis when heterogeneity is not taken into account. We created 60 data sets of 40 nuclear families each with different proportions of linked and unlinked families and with different modes of inheritance. The ascertainment probability was 0.05, the disease had a penetrance of 0.6, and the recombination fraction for the linked families was zero. For the analysis we used a variety of assumed modes of inheritance and penetrances. Under these conditions we looked at the effect of the unlinked families on the lod score, the evaluation of the mode of inheritance, and the estimate of penetrance and of the recombination fraction in the linked families. 1. When the analysis was done under the correct mode of inheritance for the linked families, we found that the mode of inheritance of the unlinked families had minimal influence on the highest maximum lod score (MMLS) (i.e., we maximized the maximum lod score with respect to penetrance). Adding sporadic families decreased the MMLS less than adding recessive or dominant unlinked families. 2. The mixtures of dominant linked families with unlinked families always led to a higher MMLS when analyzed under the correct (dominant) mode of inheritance than when analyzed under the incorrect mode of inheritance. In the mixtures with recessive linked families, assuming the correct mode of inheritance generally led to a higher MMLS, but we observed broad variation.(ABSTRACT TRUNCATED AT 250 WORDS)