Interleukin-3, GM-CSF, and TPA induce distinct phosphorylation events in an interleukin 3-dependent multipotential cell line

The mechanism of action of the hemopoietic growth factor, murine interleukin-3 (mIL-3), was investigated using an mIL-3-dependent multipotential hematopoietic cell line, B6SUtA1. Murine granulocyte- macrophage colony-stimulating factor (mGM-CSF) was as potent as mIL-3 in stimulating these cells. In addition, sodium orthovanadate, an inhibitor of phosphotyrosine phosphatase, and 12-O-tetradecanoyl- phorbol-13-acetate (TPA), a known activator of protein kinase C, also stimulated DNA synthesis in these cells, suggesting that protein phosphorylation might be involved in the mechanism of action of mIL-3 and mGM-CSF. To assess this possibility, intact B6SUtA1 cells exposed for brief periods to mIL-3, mGM-CSF, and TPA were analyzed for changes in phosphorylation patterns using metabolic 32P-labeling and antibodies to phosphotyrosine. Both mIL-3 and mGM-CSF induced the serine-specific phosphorylation of a 68-Kd cytosolic protein, whereas all three agents stimulated the serine-specific phosphorylation of a 68-Kd membrane protein. Furthermore, mIL-3 stimulated tyrosine phosphorylation of the 68-Kd membrane protein, as well as of 140-, 90-, 55, and 40-Kd proteins. The 90-Kd protein was also tyrosine phosphorylated in response to mGM-CSF. These phosphotyrosine containing proteins were not detected in TPA-treated cells. These results indicate that protein phosphorylations on tyrosine and serine residues occur in B6SUtA1 cells following short-term incubation with mIL-3 or mGM-CSF and that most of these phosphorylation events are mediated by kinases other than protein kinase C (PkC).     

Experimental intrahepatic portacaval anastomosis: use of expandable Gianturco stents

Original Gianturco expandable stents and their modifications were used to create an experimental intrahepatic portacaval anastomosis (EIPCA) in 30 young domestic swine without portal hypertension. The study focused on the design of a suitable stent, the technique of its application, and the evaluation of short-term patency of the EIPCA. A stent with a 2.5-cm-long body and wire skirts on both ends was most suitable for EIPCA creation. Well-positioned stents shunted most of the portal blood in the inferior vena cava circulation and remained patent for 4-6 weeks. Ingrowth of liver parenchyma and abundant proliferation of the intima and connective tissue inside the stent lumen in these rapidly growing animals gradually decreased EIPCA patency, and thrombus formation with diminished blood flow closed them completely.     

Cat-301 antibody selectively labels neurons in the Y-innervated laminae of the cat superior colliculus

Cat-301 is a monoclonal antibody which recognizes a cell surface associated antigen of selected neurons in the central nervous system (CNS). In the visual system, cat-301 selectively labels Y-like cells in several visual structures, including portions of the lateral geniculate nucleus complex and visual cortex. The cat superior colliculus (SC) also receives Y input and contains cells driven by Y input which are selectively distributed in the deep superficial gray and deeper laminae. If cat-301 is selective to the Y-cell system in SC, labeled cells should be restricted to those laminae. To test this hypothesis, we have examined quantitatively the laminar distribution, percentage, size, and morphology of cells in SC labeled by the cat-301 antibody. Cat-301 labeled a variety of cells in the cat SC. Labeled cells were found within the deep portion of the superficial gray layer (6.6%), optic layer (27.6%), intermediate gray layer (26.9%), and the deep gray and white layers (38.5%). By contrast, only 2 of 667 labeled cells (0.3%) were found within that part of the upper superficial gray layer innervated exclusively by W input and thought to contain only W-driven cells. When considered as a percentage of the total cell population, cat-301 labeled cells represented less than 3% of cells in the superficial gray layer and approximately 15% in the deeper layers. Neurons labeled by cat-301 were all of medium to large size (mean average diameter = 33.3 microns; range = 15-84 microns) and included vertical fusiform and stellate cells in the upper layers and the very large neurons found in the intermediate gray and deeper layers. These results provide further evidence that the cat-301 antibody selectively recognizes the Y channel of the cat visual system.     

Transient synovitis of the hip in children: role of US

Transient synovitis of the hip remains a common diagnostic problem for the clinician. The physical signs are not pathognomonic of the condition, and the classic technical examinations are of little help. Therefore, the authors retrospectively studied the value of hip arthrosonography in 46 children with clinical symptoms suggesting pathologic hip conditions. In 20 of the 21 patients with a final diagnosis of transient synovitis, articular effusion was detected on ultrasound (US). Conventional radiography showed an increased medial joint space in only eight of these patients. Increased echogenicity of the articular fluid was found in both transient synovitis and septic arthritis. The high sensitivity of US in detecting intraarticular fluid was demonstrated by cadaver studies.     

3H]muscimol labels neurons in both the superficial and deep layers of cat superior colliculus

We examined the pattern of [3H]muscimol labeling in cat superior colliculus to determine if it matches that of [3H] gamma-aminobutyric acid ([3H]-GABA) labeling or GABA antibody immunoreactivity. Injections in the superficial layers labeled cell bodies in only the superficial layers. Of 204 labeled cells, 68% were located within the upper 200 microns of the superior colliculus, 31% within the deep superficial gray layer, and only 1% below that layer, a pattern similar to that seen with [3H]GABA labeling. By contrast, an injection in the deep layers of the colliculus resulted in cell labeling in both the superficial and deep layers, including 68% in the superficial gray layer, 24% in the optic layer, and 8% in the intermediate and deep gray layers. This pattern approximates that seen with GABA immunocytochemistry. We conclude that the pattern of accumulation of [3H]muscimol depends critically upon the location of the injection and reasonably matches the pattern of GABA immunoreactivity if the injection involves the deep layers of the colliculus.     

Renal artery stenosis: evaluation with intravenous digital subtraction angiography

The ability of diagnostic intravenous digital subtraction angiography (IVDSA) to demonstrate the degree of renal artery stenosis was compared with that of intraarterial angiography in 45 patients with 92 arteries. Stenotic lesions on both IVDSA and intraarterial studies were classified as normal (0% stenosis), minor (less than 50%), low grade (50%-80%), and high grade (80%-99%). There was agreement about the degree of stenosis in 90% of the cases. IVDSA grading was correct in 94% of atheromatous lesions and in 56% of the fibromuscular dysplastic lesions. In the high-grade atheromatous lesions, the degree of stenosis was slightly overestimated on IVDSA studies in 22.5% of the cases. In fibromuscular dysplasia, stenosis was underestimated in 33% of the cases.     

STREPTOCOCCAL ANTIBODY CROSS-REACTIVITY WITH HLA-DR4+VE B-LYMPHOCYTES. BASIS OF THE DR4 ASSOCIATED GENETIC PREDISPOSITION TO RHEUMATIC FEVER AND RHEUMATIC HEART DISEASE?

B-lymphocytes obtained from patients with either rheumatic feveror rheumatic heart disease and from normal subjects were reactedwith serum obtained from rabbits immunized with streptococcalcell wall antigen. The presence of cytotoxicity was sought usingan inverted phase microscope after differential uptake of eosindye. The serum was found to be significantly more cytotoxicto HLA-DR4 containing cells of both patients and normals comparedwith DR4 negative cells (P<0. 0001). KEY WORDS: Streptococcal cell wall antigen, Antiserum, Cytotoxicity