Type II pneumocytes modulate surfactant production in response to cigarette smoke constituents: Restoration by vitamins A and E

This study was to evaluate the effects of cigarette smoke constituents upon type II pneumocyte surfactant production in vitro, and how vitamins A and E may alter the response. Freshly isolated type II pneumocytes from Sprague–Dawley rats were incubated 20 h in medium with fetal bovine serum that was or was not treated with cigarette smoke. The number of adherent cells was inversely related to the dose of smoke or benzo(a)pyrene. Despite the decreased number of treated cells, the total amount of surfactant per culture well was unchanged, whereas surfactant production per cell was significantly increased (P < 0.05). Vitamin A concentration was significantly (P < 0.05) lower in the smoke-treated serum compared with untreated serum. When vitamin A or E was added to the cigarette smoke-treated serum, cell adherence and surfactant production returned to control values. In conclusion, cigarette smoke constituents or benzo(a)pyrene alone decreased the number of adherent type II pneumocytes, but did not alter surfactant amounts because of an increased production of surfactant per cell. Type II pneumocytes seem to adjust surfactant production dependent upon the number of type II pneumocytes to produce it and vitamin A or E enhance cell attachment in the presence of the smoke toxins.     

Slow degeneration of zebrafish Rohon-Beard neurons during programmed cell death.

Rohon-Beard cells are large, mechanosensory neurons located in the dorsal spinal cord of anamniote vertebrates. In most species studied to date, these cells die during development. We followed labeled Rohon-Beard cells in living zebrafish embryos and found that they degenerate slowly, over many days. During degeneration, the soma shrinks and finally disappears, and the processes become beady in appearance and finally break apart, but they do not retract. Zebrafish Rohon-Beard cells apparently fragment their DNA, as revealed by terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling (TUNEL) labeling, before undergoing degenerative morphologic changes. We also followed the development of labeled dorsal root ganglion neurons, as they are developing at the same stages that Rohon-Beard cells are degenerating. We found that, although axons of both cell types extend into similar regions, Rohon-Beard cells degenerate normally in mutants lacking dorsal root ganglia, providing evidence that interactions between the two cell types are not responsible for Rohon-Beard cell degeneration. Developmental Dynamics 229:30-41,2004.     

Cephalosporin C acylase in the autolysis of filamentous fungi

Cephalosporin C acylase activity was studied using fluorescamine determination of free--NH2 groups produced in the deacylation of cephalosporin C by the enzyme. Fourteen fungi from different genera were studied and low extracellular cephalosporin C acylase activity was found in the genera Aspergillus, Fusarium and Penicillium. Forty one fungi of these genera were checked but not all presented acylase activity. The enzyme was generally found to be an extracellular enzyme and during the process of autolysis its activity increased with incubation time and with increasing pH of the medium. In no case was beta-lactamase activity detected. Penicillium rugulosum and Penicillium griseofulvum were identified as good cephalosporin C acylase producers. Deacetyl esterase activity was also detected in these fungi.     

A "grapple hook" technique using a deflectable tip catheter to facilitate complex proximal circumflex interventions.

We present two patients with angulated, proximal left circumflex lesions, one a chronic total occlusion and one an acute subtotal occlusion. In both cases, use of the deflectable tip Venture Catheter (Velocimed, Minneapolis, MN) facilitated guide wire passage and successful percutaneous coronary intervention (PCI) after prior attempts at guide wire passage with standard wires were unsuccessful.