Chronic immune thrombocytopenic purpura--immunological analyses of a patient pre- and post-HIV seroconversion

A seven year follow-up of immune parameters is reported for a patient with chronic immune thrombocytopenic purpura (ITP) pre and post human immunodeficiency virus (HIV) seroconversion. Therapies such as intravenous IgG, prednisone, vincristine, or Ciclosporin A had no clear-cut beneficial effect on platelet counts. A long-term normalization of platelet counts was achieved by splenectomy. At splenectomy the patient was seropositive for HIV, most likely transmitted by blood products received half a year prior to laparatomy. Mean plasma levels of the second component of complement, C2, were half of the normal values prior to and within the lowest normal range post HIV seroconversion. Nevertheless, the T cell-dependent B cell response to HIV, which is dependent on the activation of C3 via the classical pathway of complement, was normal: Western blot analysis of total IgG and of IgG subclass responses to individual HIV antigens proved to be unimpaired.     

Adhesion of canine and human uropathogenicEscherichia coli andProteus mirabilis strains to canine and human epithelial cells

Escherichia coli strains causing urinary tract infections in dogs produce fimbriae composed of fimbrial subunits closely related to the F12 and F13 fimbriae of human uropathogenic strains [4]. The adhesins carried by the fimbriae of human and canine isolates differ, however, as concluded from a different hemagglutination pattern and from the fact that the dog strains do not agglutinate latex beads coated with P-fimbriae receptor. This possible difference in adhesive specificity was confirmed by experiments in which the adhesion of human and dog isolates to dog kidney epithelial cells (MDCK cells) and human bladder epithelial cells (T24 cells) was compared. Dog uropathogenic strains, in contrast to human uropathogenicE. coli strains, adhere to MDCK cells but hardly to T24 cells. Adhesion to MDCK cells correlates with the presence of F12 or F13 fimbriae on the dog strains. These results suggest that homologous fimbrial subunits can carry different adhesin molecules and that these adhesin molecules can be responsible for species-specific adherence. On the contrary, adhesion of a number of dog uropathogenicProteus mirabilis strains to MDCK and T24 cells was not species specific; it depended on the mere presence of fimbriae.     

Application of the dual-cell coulometric detector: a method for assaying monoamines and their metabolites

A new HPLC assay technique for monoamines and their metabolites, using a controlled potential coulometric detector equipped with a dual working electrode cell of fully porous graphite through which the samples flow, is described in comparison with a classical amperometric detector equipped with a glassy carbon electrode. Different potentials can be applied at each cell of the coulometric detector to improve sample resolution and detection sensitivity. The signal-to-noise ratio (s/n) calculated in similar conditions was 10 times lower for the coulometric detector than for the amperometric one. The dual-coulometric detector does not undergo daily decay or variation, and needs no particular care or preparation. It is therefore possible to achieve stable routine sensitivity in a range of 10 fmol. This new technique has been applied for assaying monoamines and their precursors and metabolites by direct injection of clear supernatant after centrifugation and for determination of catecholamine turnover in rat pineal gland and neuro- and adenohypophysis in samples purified by Al2O3 adsorption.     

Phytosociological characteristics of theRondeletio correifoliae-Andropogonetum multinervosi ass. nova (Sierra de la Siguanea,Isla de la Juventud,Cuba)

The contribution deals with the phytocenological analysis of theRondeletio correifoliae-Andropogonetum multinervosi, an endemic savanna association occuring on the Siguanea Hills (Sierra de la Siguanea) near the Colony Hotel.     

Specific photoaffinity labeling of the digitalis binding site of the sodium and potassium ion activated adenosinetriphosphatase induced by energy transfer

A ouabain p-aminobenzenediazonium derivative with a high specific radioactivity has been synthesized from ouabain and used as a photolabel for the (sodium plus potassium)-activated adenosinetriphosphatase from Electrophorus electricus electric organ and from dog kidney. In the dark it binds reversibly to the digitalis receptor site, with binding characteristics comparable to those of ouabain. The photoactivation of the ouabain derivative to produced covalent labeling of the receptor was obtained by energy transfer from a tryptophan residue in the (Na+,K+)ATPase to the ouabain p-aminobenzenediazonium molecule bound at the active site. The great advantage of this procedure compared to previous methods is that free molecules of the photoactivatable derivative are not photodecomposed. Analysis of the photolabeled polypeptides on sodium dodecyl sulfate gel electrophoresis showed that over 90% of the total radioactivity incorporated was found in the large molecular weight alpha-chain of the kidney enzyme (Mr 93 000). The same specific labeling of the alpha-subunit was obtained with a crude microsomal fraction from Electrophorus electricus. A mild tryptic fragmentation of the subunit into two peptide fragments of Mr 58 000 and 41 000, respectively, shows that the digitalis receptor is located in the N-terminal 41 000 fragment.     

Curing of the killer character of Saccharomyces cerevisiae with acridine orange

Acridine orange, an intercalating dye usually employed in the curing of bacterial plasmids, was tested for its ability to cure K1 and K2 killer strains (laboratory and wine strains). The results showed a high curing percentage of the killer character. This was demonstrated by the loss of M1 or M2 dsRNAs (responsible for toxin production and resistance to it) and because the meiotic products exhibited non-Mendelian segregation. The curing percentages varied, depending on the strain but not on the killer type, and showed similar efficiency as compared with other known curing agents.     

Production of human to mouse xenografts by umbilical cord blood

Utilizing human umbilical cord blood, it has been possible to create in irradiated animals a human to mouse xenograft. To facilitate hematopoietic reconstitution, SJL/J mice, which are functionally low in natural killer (NK) cells, were treated with anti-Asialo GM1 antibodies (anti-NK) and irradiation prior to injection of cord blood mononuclear cells. In contrast, SJL/J mice with the "beige" (bg/bg) mutation, which confers a functional NK cell deficiency, required only irradiation for successful transplantation. Human cells, detected by means of DNA probes, were demonstrated in the lungs and lymph nodes of irradiated animals up to 6 months after injection of the human cord blood cells.     

Mouse submandibular salivary epithelial cell growth and differentiation in long-term culture: Influence of the extracellular matrix

Summary The adult mouse submandibular salivary gland provides a good model system to study gene regulation during normal and abnormal cell behavior because it synthesizes functionally distinct products ranging from growth factors and digestive enzymes to factors of relevance to homeostatic mechanisms. The present study describes the long-term growth and differentiation of submandibular salivary epithelial cells from adult male mice as a function of the culture substratum. Using a two-step partial dissociation procedure, it was possible to enrich for ductal cells of the granular convoluted tubules, the site of epidermal growth factor synthesis. Long-term cell growth over a period of 2 to 3 mo. with at least 3 serial passages was obtained only within three-dimensional collagen gels. Cells grew as ductal-type structures, many of which generated lumens with time in culture. Electron microscopic analysis in reference to the submandibular gland in vivo revealed enrichment for and maintenance of morphologic features of granular convoluted tubule cells. Reactivity with a keratin-specific monoclonal antibody established the epithelial nature of the cells that grew within collagen. Maintenance of cell differentiation, using immunoreactivity for epidermal growth factor as criterion, was determined by both cytochemical and biochemical approaches and was found to be dependent on the collagen matrix and hormones. Greater than 50% of the cells in primary collagen cultures contained epidermal growth factor only in the presence of testosterone and triiodothyronine. In contrast, cells initially seeded on plastic or cycled to plastic from collagen gels were virtually negative for epidermal growth factor. Biochemical analysis confirmed the presence of a protein with an apparent molecular weight of 6000 which comigrated with purified mouse epidermal growth factor. Epidermal growth factor was also present in detectable levels in Passage 1 cells. This culture system should permit assessment of whether modulation of submandibular gland ductal cell growth can be exerted via a mechanism that in itself includes epidermal growth factor and its receptor and signal transduction pathway. This work was supported by Public Health Service grant DE07766 from the National Institute of Dental Research, National Institutes of Health, Bethesda, MD.     

Chromosome 14 and late-onset familial Alzheimer disease (FAD)

Familial Alzheimer disease (FAD) is genetically heterogeneous. Two loci responsible for early-onset FAD have been identified: the amyloid precursor protein gene on chromosome 21 and the as-yet-unidentified locus on chromosome 14. The genetics of late-onset FAD is unresolved. Maximum-likelihood, affected-pedigree-member (APM), and sib-pair analyses were used, in 49 families with a mean age at onset ≥60 years, to determine whether the chromosome 14 locus is responsible for late-onset FAD. The markers used were D14S53, D14S43, and D14S52. The LOD score method was used to test for linkage of late-onset FAD to the chromosome 14 markers, under three different models: age-dependent penetrance, an affected-only analysis, and age-dependent penetrance with allowance for possible age-dependent sporadic cases. No evidence for linkage was obtained under any of these conditions for the late-onset kindreds, and strong evidence against linkage (LOD score ≤ –2.0) to this region was obtained. Heterogeneity tests of the LOD score results for the combined group of families (early onset, Volga Germans, and late onset) favored the hypothesis of linkage to chromosome 14 with genetic heterogeneity. The positive results are primarily from early-onset families. APM analysis gave significant evidence for linkage of D14S43 and D14S52 to FAD in early-onset kindreds (P < .02). No evidence for linkage was found for the entire late-onset family group. Significant evidence for linkage to D14S52, however, was found for a subgroup of families of intermediate age at onset (mean age at onset ≥60 years and <70 years). These results indicate that the chromosome 14 locus is not responsible for Alzheimer disease in most late-onset FAD kindreds but could play a role in a subset of these kindreds.