Factors produced by activated macrophages reduce accumulation of Alzheimer's beta-amyloid protein in vascular smooth muscle cells.

Smooth muscle cells (SMCs) isolated from amyloid-angiopathy affected brain vessels accumulate intracellularly amyloid-beta peptide (A beta). Now we demonstrate that accumulation of A beta in SMCs can be reduced by factors secreted by macrophages - IL-1alpha, IL-6, TNF-alpha, TGF-beta1 or PGE2 - probably by stimulating the non-amyloidogenic processing of A beta precursor protein (PP). It is suggested that brain macrophages may regulate A betaPP/A beta metabolism under physiological conditions and prevent beta-amyloidosis. The disturbance of this regulatory function of brain macrophages may result in excessive production and accumulation of A beta.

Promotion of synthetic amyloid beta-peptide fibrillization by cell culture media and cessation of fibrillization by serum.

Dulbecco's modified Eagle's medium promotes aggregation and fibrillization of the synthetic amyloid beta 1-40 and beta 1-42 peptides more than RPMI and OPTI media. Fibrillization in all of these media is faster than in phosphate-buffered saline and Tris buffer. Normal and heat-inactivated fetal bovine and human serum abolish amyloid fibril formation in buffers and cell culture media. Fibrillar amyloid formed during 2-day-long incubation in cell culture media and buffers is defibrillized by 1-day-long treatment with human and bovine serum. This study indicates that amyloid beta fibrillogenesis in cell culture should be studied in serum-free media or in media with a low concentration of serum.

Angioplasty for the treatment of visceral ischemia.

PURPOSE: To evaluate percutaneous transluminal angioplasty (PTA) in the treatment of visceral ischemia. PATIENTS AND METHODS: Over a 14-year period, 25 focal visceral artery stenoses were treated with PTA in 16 patients with acute or chronic visceral ischemia. Thirteen patients were women and three were men, with a mean age of 64.7 years (range, 54-79 years). PTA was performed in seven celiac arteries, 17 superior mesenteric arteries, and one inferior mesenteric artery. RESULTS: PTA was technically successful in 14 of 16 patients (88%). Two patients were lost to follow-up. Nine of 12 patients (75%) demonstrated primary patency with relief of clinical symptoms at a mean follow-up of 2.3 years (range, 0.3-5 years). The remaining three patients underwent successful repeat PTA for recurrent symptoms. There was one postprocedural death, and one patient subsequently underwent successful surgical bypass for recurrent visceral ischemia. CONCLUSIONS: Angioplasty of the visceral arteries may provide relief for select patients with intestinal ischemia, but redilation may be required in some patients.

Stereotactic needle biopsy of nonpalpable breast masses.

One hundred two patients with nonpalpable breast masses that presented as mammographic densities with or without calcification were studied consecutively. Using the Stereotix stereotactic device, fine-needle aspirations were obtained with subsequent hook-wire placement followed by surgical excision. Pathology results were reached separately and then compared to the cytologic diagnoses. For patients with adequate cytologic material, sensitivity was 95% and specificity was 100%. There were six suspicious or equivocal diagnoses: three were determined to be benign, while three were malignant. There was inadequate tissue in 13%. Although this technique had limitations, for patients with adequate cytologic and histologic material the accuracy was excellent.

Spontaneous renal rupture: evaluation by computerized tomography.

We report an unusual case of spontaneous renal rupture, including intrarenal and perirenal hemorrhage, which was evaluated by computerized tomography. Various causes of spontaneous rupture are discussed and a possible mechanism in this patient is suggested.

Binding of calmodulin to the neuronal cytoskeletal protein kinase type II cooperatively stimulates autophosphorylation.

The kinetics of autophosphorylation of the cytoskeletal form of the neuronal calmodulin-dependent protein kinase type II were studied as a function of calmodulin binding under the same conditions. Whereas calmodulin binding was noncooperative with respect to calmodulin concentration (Hill coefficient = 1), the activation of autophosphorylation and the phosphorylation of exogenous substrates showed marked positive cooperativity (Hill coefficient greater than or equal to 1.6). Reduction of the active calmodulin concentration by the addition of the calmodulin antagonist trifluoperazine confirmed the cooperative nature of enzyme activation, because autophosphorylation was more sensitive to the drug than was binding at high concentrations of calmodulin. At intracellular levels of calmodulin the binding and activation of autophosphorylation were cooperative functions of magnesium and calcium concentration. The calmodulin-dependent cooperative activation seems to be a unique feature of the cytoskeletal, but not the soluble, form of the protein kinase and may result from the supramolecular organization of the cytoskeletal enzyme. These observations suggest that interactions among the subunits of the oligomeric cytoskeletal calmodulin-dependent protein kinase regulate enzyme activation, enhancing the sensitivity of the enzyme to small changes in the intracellular calcium levels that may be particularly relevant to signaling at the synapse.

Competitive binding assay for drugs that interfere with calmodulin function.

A direct 125I-calmodulin-binding system utilizing a particulate cytoskeletal preparation of the neuronal calmodulin-dependent protein kinase type II provides a simple, rapid filtration-based method for assessing anti-calmodulin drug activity. The binding assay avoids potential artifacts due to direct drug effects on the standard phosphodiesterase enzyme assay while obtaining comparable IC50 values for a spectrum of drugs. It also provides a tool to probe mechanisms of action of putative anticalmodulin agents which may help elucidate selective pharmacologic modifications of pathophysiological processes.

A comparison of Hexabrix and Renografin 60 in peripheral arteriography.

Fifty-one patients were analyzed after a randomized double-blind study comparing Hexabrix and Renografin 60 in peripheral arteriography. The arteriographic studies and the volumes of contrast material used in both groups were similar. Hexabrix caused significantly less pain and discomfort than Renografin 60, and the diagnostic quality of the radiographs was comparable. A slightly higher incidence of minor side effects was noted in the Hexabrix group, mostly nausea and vomiting and urinary retention.

A nonoperative technique for establishment of a gastrostomy in the dog.

Gastrostomies have been performed nonoperatively under local anaesthesia using a simultaneous percutaneous and endoscopic approach. This technique has been modified to be done under fluoroscopy without the need for endoscopy. The technique and results in five dogs are described.

A comparison of hexabrix and Renografin 60 in peripheral arteriography.

Fifty-one patients were analyzed after a randomized double-blind study comparing Hexabrix and Renografin 60 in peripheral arteriography. The arteriographic studies and the volumes of contrast material used in both groups were similar. Hexabrix caused significantly less pain and discomfort than Renografin 60, and the diagnostic quality of the radiographs was comparable. A slightly higher incidence of minor side effects was noted in the Hexabrix group, mostly nausea and vomiting and urinary retention.

The cervical split: a pseudofracture.

A horizontal lucent line projecting over a cervical vertebral body on lateral radiographs and simulating a fracture is described. The pseudofracture line results from the lucency between contiguous proliferative osteophytes at the uncinate process/vertebral articulation. Associated disc space narrowing was seen in all of our eleven cases. The origin of this pseudofracture line, cases illustrating this phenomenon, and additional projections helpful for clarification are presented.

Ultrasonic visualization of the posterior thoracic aorta in long axis: diagnosis of a saccular mycotic aneurysm.

A saccular aneurysm arising from the descending thoracic aorta was identified ultrasonically in a 60-year-old man with a subsequent pathologic diagnosis of a Listeria monocytogenes mycotic aneurysm. A cross-sectional scanning technique, which permitted visualization of the descending thoracic aorta in long axis, demonstrated a 3 X 5 cm relatively echo-free mass between the heart and the aorta. A communication between the mass and the aorta established the diagnosis of an aneurysm.