Small isolated paraspinal arteriovenous fistula.

We report a case of a small, isolated paraspinal arteriovenous fistula (AVF) that arose in an adult without obvious trauma. The fistula, despite its extraspinal location and small size, caused hypertension of the intrathecal venous system and produced symptoms that were similar to those of spinal dural AVF. Detecting such a small lesion is difficult, but contrast-enhanced MR imaging can prove helpful in this regard.     

NMR Microscopy of Single Neurons Using Spin Echo and Line Narrowed 2DFT Imaging

NMR microimages of single neural cells were acquired at 500 MHz using a conventional spin echo pulse sequence and a line-narrowing sequence that eliminates susceptibility effects. The data show that any contribution to the measured T₂ relaxation rate arising from diffusion in local field inhomogeneities using spin echo sequences at high fields and high spatial resolution is relatively small. We conclude that the measured T₂ difference between the nucleus and cytoplasm in these cells represents primarily a true T₂ relaxation effect arising from the interactions of water with macromolecules in the two compartments and does not result from microsusceptibility differences. These observations have implications regarding water compartmentation in single cells and the interpretation of the MR characteristics of tissues in vivo.     

Coexpression of galanin and adrenocorticotropic hormone in human pituitary and pituitary adenomas.

Galanin is a neuropeptide that regulates the secretion of several pituitary hormones, including prolactin (PRL) and growth hormone (GH). Galaninlike immunoreactivity (Gal-IR) and galanin mRNA in the rat anterior pituitary is cell lineage specific, with predominant expression in lactotrophs and somatotrophs. The authors examined the cellular distribution of human Gal-IR in seven normal postmortem pituitaries and 62 pituitary tumors by immunoperoxidase staining. In contrast to the rat, Gal-IR in human anterior pituitaries was present in corticotrophs scattered throughout the gland, but not in lactotrophs, somatotrophs, thyrotrophs, or gonadotrophs. Distinct Gal-IR also was present in hyperplastic and neoplastic corticotrophs in 19 of 22 patients with Cushing's disease. In noncorticotroph cell tumors, unequivocal Gal-IR was present in 5 of 11 GH-secreting tumors associated with clinical acromegaly, 9 of 18 nonfunctioning pituitary adenomas, and 2 of 14 prolactinomas. Of these galanin-positive tumors, four of the five GH-secreting adenomas, six of the nine nonfunctioning adenomas, and both of the prolactinomas also contained adrenocorticotropic hormone immunoreactivity (ACTH-IR). Immunostaining and in situ hybridization on adjacent sections using an 35S-labeled probe complementary to human galanin mRNA demonstrated predominant galanin expression in normal corticotrophs. Immunoelectron microscopy confirmed the presence of Gal-IR in pituitary cells characteristic of corticotrophs in both normal and neoplastic pituitaries. Thus, as in the rat, galanin gene expression in the human pituitary is cell-type specific. Unlike the rat, however, human galanin gene expression is restricted to the corticotroph lineage. Studies of tumors confirmed the observed coexpression of galanin and adrenocorticotropic hormone. The divergent cell type specificity of galanin production in human and rat pituitaries reflects different patterns of gene activation in these two species. In addition, these results suggest that galanin in the human pituitary may participate locally in the regulation of the hypothalamic-pituitary-adrenal axis.     

Drosophila awd, the homolog of human nm23, regulates FGF receptor levels and functions synergistically with shi/dynamin during tracheal development

Human nm23 has been implicated in suppression of metastasis in various cancers, but the underlying mechanism of such activity has not been fully understood. Using Drosophila tracheal system as a genetic model, we examined the function of the Drosophila homolog of nm23, the awd gene, in cell migration. We show that loss of Drosophila awd results in dysregulated tracheal cell motility. This phenotype can be suppressed by reducing the dosage of the chemotactic FGF receptor (FGFR) homolog, breathless (btl), indicating that btl and awd are functionally antagonists. In addition, mutants of shi/dynamin show similar tracheal phenotypes as in awd and exacerbate those in awd mutant, suggesting defects in vesicle-mediated turnover of FGFR in the awd mutant. Consistent with this, Btl-GFP chimera expressed from a cognate btl promoter-driven system accumulate at high levels on tracheal cell membrane of awd mutants as well as in awd RNA duplex-treated cultured cells. Thus, we propose that awd regulates tracheal cell motility by modulating the FGFR levels, through a dynamin-mediated pathway.     

Use of multivariate statistical methods to identify immunochemical cross‐reactants

Quantitative competition immunoassays with appropriate combinations of antibodies give consistent dose‐response patterns which may be used to identify and estimate amounts of cross‐reacting compounds. Previously reported methods of analyzing cross‐reaction patterns include multiple regression, principal components analysis and minimum estimates of variance (MEV). Four other techniques which are preferable in theory have been surveyed: discriminant analysis (DA), maximum likelihood estimates (MLE), classification and regression trees (CART), and computational neural networks (NN). MLE and simple back‐propagation neural networks can estimate the concentration, as well as the identity, of individual compounds. These four methods worked well with unfitted, unscaled data from monoclonal assays of triazines, phenylureas and avermectins. Immunoassays must be properly designed to provide adequate data for pattern recognition. Cross‐reactivity pattern analysis will make multi‐analyte, multi‐antibody immunoassays feasible for many applications in toxicology and hazard assessment.     

Alterations in the genomes of avian sarcoma viruses

We have identified polypeptides specific to region Elb (map position [mp] 4.6–112) of adenovirus 2 (Ad2) that are synthesized in six lines of Ad-transformed rat or human cells (F17, F4, T2C4, 8617, 5RK clone I, 293), and in Ad2 early infected KB cells. [³⁵S]Methionine-labeled polypeptides were immunoprecipitated using antisera against F17 cells, an Ad2-transformed rat cell line that retains only El. To determine whether they are viral coded, these polypeptides were compared by tryptic peptide mapping with polypeptides translated in vitro from Ela-specific mRNA (mp 1.3–4.5) and Elb-specific mRNA. Polypeptides of 19,000 daltons early infected KB cells. The 19K, 20K, and 53K could be translated from Elb-specific mRNA and thus are coded by Elb. The 19K was precipitated from all transformed cell lines, the 20K was immunoprecipitated from F4, 8617, and T2C4 cells, and the 53K was immunoprecipitated from F4, 8617, T2C4, and 293 cells. These results suggest that the 19K, and perhaps the 20K and 53K, may be important in adenovirus-induced cell transformation. The 20K and 53K share methionine-containing tryptic peptides with each other, but not with the 19K. These results, together with the Ad2 Elb DNA sequence (T. Gingeras and R. Roberts, personal communication), suggest that 19K is translated in a different reading frame from 53K and 20K.     

C3d antiglobulin haemagglutination of human red blood cells. A demonstration of two types of cell-bound C3d by means of typsin digestion.

Washed human red blood cells from blood collected in EDTA were tested by Auto-Analyzer for a percentage of maximum antiglobulin haemagglutination (AH) using monospecific antisera to human C3d and C3c. The cells from normal persons were found to be agglutinated by anti-C3d but not by anti-C3c. To a fixed dilution of antiserum, the normal C3d AH values (X +/- 2 SD) were 34 +/- 19% for adult cells (n = 29) and 14 +/- 19% for cord cells (n = 19); the difference was significant (P less than 0.0001). By pretreatment of these cells with trypsin the C3d AH was either completely abolished or markedly reduced. Its difference between the adult and cord cells was eliminated as the observed values were 4 +/- 7% and 3 +/- 4% respectively (P = 0.15). The supernatant fluid of cell-trypsin mixture, treated with trypsin inhibitors, was found to be inhibitory to C3d AH but not to C3c AH. In contrast, the AH of C3d-coated red blood cells resulting from complement fixation in vivo (ie, cold agglutinin disease) or in vitro (eg, sucrose water reaction) was resistant to trypsin treatment. The difference between the trypsin-sensitive and trypsin-resistant cell-bound C3d is postulated to be at its attachment mechanism to the cell membranes. In addition, both the advantage and limitation of using trypsinised cells for C3d antiglobulin tests are demonstrated.     

The syndrome of ectrodactyly, ectodermal dysplasia and cleft lip and palate: report of a family demonstrating a dominant inheritance pattern

The syndrome of ectrodactyly, ectodermal dysplasia and cleft lip and palate (EEC syndrome) is described in a mother and 3 of her 4 children. Autosomal dominant inheritance was suggested in this family. However, genetic heterogeneity may exist in this syndrome. The significance of associated finClings, incluCling carcinoma of the cervix uteri, lacrimal duct stenosis and urinary tract strictures in patients with ectodermal dysplasia is considered.     

Specific and nonspecific immune factors in dental plaque fluid and saliva from young and old populations.

Separate samples of supragingival dental plaque overtly free of blood were centrifuged to obtain the free fluid phase (plaque fluid). Bound protein was eluted from the plaque bacteria and matrix by washing the plaque with a low-pH buffer. The plaque fluid, low pH eluate, and whole saliva were assayed for immunoglobulins A, G, and M, the third component of complement, lysozyme, lactoferrin, and lactoperoxidase. Concentrations of total protein and albumin were also determined. Antibody reactive with specific plaque bacteria was detected by indirect immunofluorescent microscopy. Specific and nonspecific immune proteins were present in plaque fluid from adult subjects at significantly greater concentrations than in their saliva, which suggests that these proteins are concentrated in dental plaque. The results indicate that both saliva and gingival exudate contribute to the immunological proteins found in the free fluid phase of dental plaque. The observation that immunoglobulin A antibody reactive with plaque bacteria could be detected in plaque fluid suggests that a wide variety of immunological reactions may occur in the dental plaque. These potential interactions between host, plaque bacteria, and their products could serve to influence the plaque flora and its ability to induce disease.