Extended HLA profile of an inbred isolate: The Schmiedeleut Hutterites of South Dakota

HLA-A, -B, -C, -DR, and -DQ typings of the Schmiedeleut Hutterites of South Dakota were collected as part of an ongoing genetic-epidemiologic study of HLA and fertility. A total of 1,082 individuals, including 852 married adults representative of the reproductive population of this isolate, were characterized for five-locus HLA haplotypes. HLA-A1, A2, A3, and A24 accounted for 75% of observed HLA-A alleles and HLA-B27, B35, B51, and B62 accounted for 55% of observed HLA-B alleles. S-leut Hutterites are derived from 68 or fewer ancestors. However, only 48 ancestral HLA haplotypes were observed and nine of these accounted for over 52% of the observed haplotypes. Measures of two-locus linkage disequilibrium derived from these haplotypes indicated that one-third to half of the observed HLA-A/B, B/DR, and A/DR allele combinations exhibited highly statistically significant linkage disequilibrium. Allele and haplotype frequencies did not differ between males and females. Recombination rates of 0.004% and 0.005% between HLA-A and -C and between HLA-B and -DR, respectively, were observed. This HLA profile points out a paucity of HLA alleles and haplotypes in this population and marked linkage disequilibrium among the HLA alleles that are present. © Wiley-Liss, Inc.     

Wallstent metallic biliary endoprosthesis: MR imaging characteristics.

Image quality and safety of magnetic resonance (MR) imaging were evaluated in vitro and in eight patients with the most commonly employed metallic biliary endoprosthesis. In vitro, the stent produced no tip deflection at 0.6 or 1.5 T. Trace magnetic susceptibility artifact, similar to artifact from a column of air, paralleled the stent. In patients, image degradation was minimal with conventional pulse sequences. Middle-field-strength spin-echo images revealed minimal artifacts indistinguishable from those produced by pneumobilia.     

The G-protein-coupled receptor kinases beta ARK1 and beta ARK2 are widely distributed at synapses in rat brain.

The beta-adrenergic receptor kinase (beta ARK) phosphorylates the agonist-occupied beta-adrenergic receptor to promote rapid receptor uncoupling from Gs, thereby attenuating adenylyl cyclase activity. Beta ARK-mediated receptor desensitization may reflect a general molecular mechanism operative on many G-protein-coupled receptor systems and, particularly, synaptic neurotransmitter receptors. Two distinct cDNAs encoding beta ARK isozymes were isolated from rat brain and sequenced. The regional and cellular distributions of these two gene products, termed beta ARK1 and beta ARK2, were determined in brain by in situ hybridization and by immunohistochemistry at the light and electron microscopic levels. The beta ARK isozymes were found to be expressed primarily in neurons distributed throughout the CNS. Ultrastructurally, beta ARK1 and beta ARK2 immunoreactivities were present both in association with postsynaptic densities and, presynaptically, with axon terminals. The beta ARK isozymes have a regional and subcellular distribution consistent with a general role in the desensitization of synaptic receptors.     

Use of calcium alginate to pack abscess cavities: a controlled clinical trial.

Many conventional dressings are painful when removed, and may be detrimental to healing. In a pilot study ten consecutive abscesses, requiring incision and drainage, were packed with a calcium alginate dressing: this was well tolerated, its removal causing minimal pain. No adverse effects were attributable to its use. A controlled trial was therefore carried out to compare calcium alginate with the more traditional saline-soaked gauze for packing abscess cavities, following incision and drainage. Patients were randomized to receive either calcium alginate (16 patients) or gauze dressing (18 patients). At the first dressing change the patient marked on a linear analogue scale the pain experienced; the nurse noted similarly the ease of removal of the dressing. Calcium alginate was significantly less painful to remove after operation (P less than 0.01), and also easier to remove (P less than 0.01) than gauze dressings. If abscess cavities are packed after incision and drainage, calcium alginate appears to be an improvement on conventional dressings.     

Development of a new wound dressing with antimicrobial delivery capability

A bilaminar wound dressing composed of an outer membrane and an inner three-dimensional matrix of a fabric or a sponge may be considered to constitute an ideal structure that promotes wound healing: the outer membrane prevents body fluid loss, controls water evaporation, and protects the wound surface from bacterial invasion, and the inner matrix encourages adherence by tissue growth into the matrix. Using this concept, we developed a biosynthetic wound dressing with a drug delivery capability. This medicated wound dressing is composed of a spongy sheet of a chitosane derivative and collagen mixture that is laminated to an antimicrobial-impregnated polyurethane membrane. In this study, a gentamycin sulfate-impregnated wound dressing was prepared and evaluated. The antimicrobial efficacy of this wound dressing was examined on an agar plate seeded with Pseudomonas aeruginosa. Also, the cytotoxicity of an antimicrobial released from this wound dressing was examined in an in vitro system with cultured skin substitutes. Both in vitro tests have shown that this wound dressing is capable of suppressing bacterial growth and minimizing cellular damage. In addition, in the treatment of wounds inflicted on rats and rabbits, this wound dressing was shown to be efficacious in covering full-thickness and split-thickness skin defects. Finally, the efficacy of this wound dressing was evaluated in a nonrandomized open-label study of 31 clinical cases. In 31 cases treated with this wound dressing, good or excellent wound healing was achieved.     

Detection and partial purification of a potent mitogenic factor for human thyroid follicular cells.

Normal adult human thyroid follicular cells have an extremely limited proliferative capacity in vitro. No previously studied mitogen, including thyrotropin (TSH) or epidermal growth factor (EGF), has in our hands resulted in a significant improvement over the 3-4% nuclear [3H]thymidine pulse-labelling index (LI) obtainable with 10% fetal calf serum. Here we report the detection in the conditioned medium from a sub-clone of NIH3T3 fibroblasts of a mitogenic activity capable of increasing this response up to 10-fold, to an LI of over 20%, together with an even greater relative stimulation of mitotic activity. Preliminary characterisation has excluded EGF and TGF alpha, and demonstrated that the activity is bound reversibly by heparin-Sepharose, thus pointing to a member of the heparin-binding fibroblast- or hepatocyte-growth factor families. This material should have wide practical application in facilitating primary culture of follicular cells, and may reveal new mechanisms of stromal-epithelial interaction regulating normal and neoplastic thyroid growth in vivo.