Stent coating with titanium-nitride-oxide for reduction of neointimal hyperplasia.

BACKGROUND: Coronary stents prevent constrictive arterial remodeling but stimulate neointimal hyperplasia. Stainless steel induces a metallic foreign body reaction, which is absent for titanium. The hypothesis of the present study was that titanium renders the stent surface biologically inert, with reduced platelet and fibrinogen binding. METHODS AND RESULTS: Twelve pigs were instrumented with a stainless steel and 2 titanium-nitride-oxide-coated stents (TiNOX 1, ceramic; TiNOX 2, metallic). Animals were restudied after 6 weeks. Histological specimens of stented segments were analyzed by digital morphometry. Platelet adhesion and fibrinogen binding studies were performed in the perfusion chamber. Under in vitro conditions, TiNOX 1 showed reduced platelet adhesion (65+/-3%) compared with TiNOX 2 (72+/-5%; P<0.05) and stainless steel (71+/-4%; P<0.05). Platelet adhesion 48 hours after incubation with human plasma, however, was not different between TiNOX 1 (17+/-3%) and 2 (15+/-3%) but was significantly higher with stainless steel (23+/-2%; P<0.05). Fibrinogen binding was significantly reduced with TiNOX 2 (54+/-3%) compared with TiNOX 1 (82+/-4%, P<0.05) or stainless steel (100%, P<0.05). Histomorphometry revealed a significantly larger neointimal area in stainless steel (2.61+/-1.12 mm(2)) than in TiNOX 1-coated (1.47+/-0.84 mm(2), P<0.02) or TiNOX 2-coated (1.39+/-0.93 mm(2), P<0.02) stents. The reductions were 44% and 47%, respectively. CONCLUSIONS: TiNOX coating significantly reduces neointimal hyperplasia in stainless steel stents. The antiproliferative effect was similar for both TiNOX coatings, suggesting that the electrochemical properties are more important for attenuation of neointimal proliferation than the observed differences in platelet adhesion and fibrinogen binding.

Does captopril have a direct pro-apoptotic effect?

The beneficial effect of ACE inhibitors on cardiovascular remodelling from hypertension and ischemic disease may be due to the effect of these drugs on the proliferation/cell death balance. We therefore investigated the effect of the addition of captopril in vitro, on the onset of apoptosis in human vascular myocytes, by using a propidium iodide fluorescence analysis and a morphological analysis using the acridine orange technique. Captopril (0.23 mM) caused an increase in apoptotic phenomena that was more than 3. 5-fold than in controls both at the 24th (7.7 vs. 2%) and the 48th h (10.1 vs. 3.8%). The addition of propranolol strengthened the effect on apoptosis. The induction of apoptotic phenomena may be a mechanism by which ACE inhibitors affect cardiovascular remodelling and it might also explain the favorable effect these drugs have on diseases such as IgA nephropathy and diabetic nephropathy.

[Acute cholangiopancreatitis in a patient with a duodenal diverticulum at Vater's ampulla]. / Colangiopancreatite acuta in un paziente con papilla di Vater in diverticolo duodenale.

A case of duodenal diverticulum complication (cholangiopancreatitis) in a patient of 62 years old is reported. It has been treated successfully by endoscopic sphincterotomy technique.

[Effect of the resection margin and the extrarectal spread on the recurrence following 2 types of surgical procedures in rectal cancer]. / Influencia del margen de sección y de la diseminación extrarrectal en la recidiva después de dos tipos de intervenciones por cáncer de recto.

A prospective unrandomized clinical study was conducted to determine the incidence of local recurrences after radical surgery and to ascertain whether the anterior resection could be an effective approach in cases of the tumours of the rectum, also in presence of the unsatisfied distal clearance and the extraparietal spread. For this purpose the length of the rectum below the tumor, mesorectum included, was cut in little cubes of 1 square cm and 10 microslices/cm at random were histologically examined to locate the intramural diffusion and extraparietal spread. Sixty-one patients undergoing curative surgery for rectal cancer entered the trial. Thirty-seven of them have been operated on by anterior resections (AR) and twenty-four by abdominal-perineal amputation. Thirteen local recurrences (21.3%) have been recorded during a five-year follow-up: 9 after AR and 4 after Miles operation. Nine relapses were among the cases with distal clearance less than 3 cm an eight of these have undergone anterior resections. No recurrence was seen in cases with distal clearance greater than 5 cm. Spread was found in 11 (18%) patients. Five recurrences were recorded all belonging to the group with anterior resection. No statistical difference exists between conservative surgical procedure and abdominal-perineal operation. We have been able to demonstrate only the direct relationship between relapse and Dukes C stage after curative rectal surgery.

Phospholipid metabolism of stimulated lymphocytes. Composition of phospholipid fatty acids.

Lymph node lymphocytes and thymocytes from different species were isolated. Rabbit and calf thymocytes were stimulated in vitro with concanavalin A. Phospholipid fatty acids of these cells were analyzed and their positional distribution was determined. When compared with liver, phosphatidylcholine of unstimulated lymphocytes was found to contain relatively high amounts of palmitic acid in position 2 and oleic acid in position 1. After stimulation of rabbit thymus cells, the content of polyunsaturated fatty acids (linoleic and arachidonic acid) increased. Thus the ratio of polyenoic acids (18:2 + 20:4) to saturated fatty acids was doubled when compared to control cells. Similar results were obtained after in vivo stimualtion with Mycobacterium Calmette Guerin. The correlation of these findings with the activation of acyl-CoA:lysolecithin acyltransferase, and their relevance for changes of membrane fluidity during lymphocyte stimulation is discussed.