Rotational ablation of balloon angioplasty failures

In this series, we evaluated the use of rotational ablation in stenoses that were previously refractory to balloon angioplasty. Forty-one stenoses were treated; in 26, the balloon did not adequately expand within the lesion and in 15 the balloon could not be delivered to the stenosis. Rotational ablation was technically successful in 40 of 41 (97.6%) of the lesions attempted. Twenty-four patients have been followed (mean time = 9 +/- 5 months) and the restenosis rate was similar to that of balloon angioplasty. Rotational ablation appears well suited and may be the treatment of choice for heavily calcified, severely angulated, and diffusely diseased vessels.     

Achalasia of the Cardia Associated with Hereditary Cerebellar Ataxia

Achalasia of the cardia, a disorder associated with degenerative loss of esophageal myenteric ganglion cells, is reported in association with a recently described progressive neurological disorder, "early onset cerebellar ataxia with retained reflexes." This form of cerebellar ataxia is thought to be inherited as an autosomal recessive disorder. The occurrence of these two very rare neurodegenerative disorders in a single individual is of interest because of the potential genetic and pathogenetic implications of the association.     

Two distinct quisqualate receptors regulate Ca2+ homeostasis in hippocampal neurons in vitro

Addition of quisqualate to mouse hippocampal neurons in vitro elicited two types of changes in [Ca2+]i as assessed by fura-2-based microfluorimetry. The first was a transient spike or group of oscillations and the second was a long lasting "plateau" response. The long-lasting response was abolished on removal of either Ca2+ or Na+ from the external medium or by blocking voltage-sensitive Ca2+ channels. Furthermore, the novel glutamate antagonist 6-nitro-7-cyano-quinoxaline-2,3-dione was a competitive inhibitor of this response. In contrast, none of these manipulations abolished the transient [Ca2+]i spike. Transient [Ca2+]i spikes or oscillations could also be produced by the alpha 1-adrenergic agonist phenylephrine. Production of such an alpha 1-response reduced the size of a subsequently elicited quisqualate response. However production of transient [Ca2+]i spikes with caffeine did not alter the size of the quisqualate-induced spike. We conclude that hippocampal neurons possess two different types of quisqualate receptors. The first mediates quisqualate-induced depolarization and the second mediates Ca2+ mobilization from intracellular stores.     

Experimental Induction of Atheroarteriosclerosis by the Synergy of Allergic injury to Arteries and Lipid-Rich Diet: II. Effect of Repeatedly Injected Foreign Protein in Rabbits Fed a Lipid-Rich, Cholesterol-Poor Diet

Rabbits fed a lipid-rich, cholesterol-poor diet and given concomitant injections of foreign protein, over a period as long as 17 months, developed in their coronary arteries both a) proliferative fibromuscular intimal thickening closely resembling the diffuse intimal thickening that commonly occurs in coronary arteries of man, and b) fatty-proliferative fibromuscular intimal thickening that closely resembles coronary atherosclerosis in man. In contrast, rabbits of another group that were concurrently fed the same diet for as long as 22 months without injections of foreign protein developed changes in arteries of their hearts that resemble neither coronary atherosclerosis nor diffuse intimal thickening in man. Fatty-proliferative changes in aortas of the first group of rabbits are strikingly greater and more closely resemble human aortic atherosclerosis than those in the latter group. In the course of the experiments, the average serum cholesterol was not significantly different in the two groups of rabbits. It was approximately 200 to 250 mg%, which is the average serum cholesterol in adult humans in the United States. These experiments support the hypothesis that the synergy of arterial injury, in particular immunologic injury, and a diet rich in lipid can lead to atherosclerosis in man.     

Visceral target organs in systemic St. Louis encephalitis virus infection of hamsters

Ultrastructural aspects of St. Louis encephalitis virus infection of the major extraneutral organs and tissues of suckling hamsters were examined. In the pancreas, both the exocrine and endocrine portions were equally affected by the virus. A feature apparently unique to flaviviruses was the accumulation of virus particles in all types of secretory granules in this organ. Virus particles were seen within myocardial fibers and within the smooth muscle cells and endothelial cells of small blood vessels of the heart. In the intestines, the lamina propria was the most severely infected, with virus particles accumulated in all cell types.     

Evaluation of screened blood donations for human immunodeficiency virus type 1 infection by culture and DNA amplification of pooled cells

BACKGROUND. Reports of transmission of the human immunodeficiency virus type 1 (HIV-1) from transfusions of screened blood and reports of silent, antibody-negative HIV-1 infections in persons at high risk continue to foster concern about the safety of the blood supply. Previous estimates of the risk of HIV-1 range from 1 in 38,000 to 1 in 300,000 per unit of blood but are based on either epidemiologic models or the demonstration of seroconversion in recipients. METHODS. We isolated peripheral-blood mononuclear cells from blood that was fully screened and found to be seronegative, combined them into pools of cells from 50 donors, and tested them for HIV-1 by viral culture and the polymerase chain reaction, using protocols specifically adapted for this analysis. RESULTS. The 1530 pools of mononuclear cells were prepared from 76,500 blood donations made in San Francisco between November 1987 and December 1989. Of these pools, 1436 (representing 71,800 donations) were cultured successfully; 873 (43,650 donations) were evaluated by the polymerase chain reaction. Only one pool was confirmed as HIV-1--infected by both methods. After adjustment for sample-based estimates of the sensitivity of the detection systems using culture and the polymerase chain reaction, the probability that a screened donor will be positive for HIV-1 was estimated as 1 in 61,171 (95 percent upper confidence bound, 1 in 10,695). CONCLUSIONS. Silent HIV-1 infections are exceedingly rare among screened blood donors, so the current risk of HIV-1 transmission from blood transfusions, even in high-prevalence metropolitan areas, is extremely low.     

Quantitative Studies on the Proliferation and Differentiation of Antibody-Forming Cells in Lymph

The transforming cells that appear in the efferent lymph from a lymph node responding to an antigenic challenge are part of a heterogeneous population which changes as the response progresses. Some cells containing small amounts of antibody appear early in the response and these cells have the cytologic characteristics of small and medium lymphocytes. They are, however, actively synthesizing DNA. As the immune response progresses, the antibody content of the cells in lymph increases. When incubated in vitro, cells in lymph appearing late in the response released 20 times more antibody per cell than those appearing early in the response. Large blast cells are the predominant antibody-forming cell in lymph. At the peak of a secondary challenge with horseradish peroxidase, up to 40% of the cells in lymph may be blast cells and, of these, two-thirds may contain specific antibody. It seems probable that most if not all of the blast cells responding to the antigen are involved directly in antibody and DNA synthesis. Cells in all stages of ultrastructural differentiation, and even mature plasma cells, were found to incorporate ³H-thymidine into their nuclear DNA.