Polydeoxyribonucleotides and nitric oxide release from guinea-pig hearts during ischaemia and reperfusion.

1. Two polydeoxyribonucleotides, produced by the controlled hydrolysis of DNA of mammalian lung (defibrotide and its lower molecular weight fraction, P.O. 085 DV), were studied for their ability to modify the release of nitrite and the coronary flow in perfusates collected from isolated, normally perfused hearts of guinea-pigs and from hearts subjected to regional ischaemia and reperfusion. 2. In guinea-pig normally perfused hearts, both defibrotide (DFT) and its fraction, P.O. 085 DV, increase the amount of nitrite appearing in perfusates in a concentration-dependent fashion. At the highest concentration studied (10(-6) M), P.O. 085 DV was more effective than DFT. A concomitant increase in the coronary flow was observed. 3. The increase in nitrite in perfusates and the increase in coronary flow induced by both DFT and P.O. 085 DV were significantly reduced by NG-monomethyl-L-arginine (L-NMMA, 10(-4) M), an inhibitor of nitric oxide synthase (NOS). 4. The endothelium-dependent vasodilator, acetylcholine (ACh), enhances the formation of nitrite and the coronary flow. Both the increase in coronary flow and in the formation of nitrite were significantly reduced by L-NMMA (10(-4) M). 5. In guinea-pig hearts subjected to ischaemia and reperfusion, the effect of both compounds in increasing the amount of nitrite in perfusates was more evident and more pronounced with P.O. 085 DV. 6. Reperfusion-induced arrhythmias were significantly reduced by both compounds to the extent of complete protection afforded by compound P.O. 085 DV. 7. The cardioprotective and antiarrhythmic effects of DFT and P.O. 085 DV are discussed.     

IFNgamma and TNFalpha account for a pro-clonogenic activity secreted by activated murine peritoneal macrophages

In the present study, we found that murine peritoneal macrophages elicited by BCG or Listeria monocytogenes release into the media an activity capable of stimulating the lung colonization as well as the expression of MHC class I antigens in B16 melanoma cells. A similar activity has previously been found in media conditioned by Corynebacterium parvum-elicited macrophages. Analysis by gel filtration chromatography of media conditioned by Corynebacterium parvum-, BCG- or Listeria monocytogenes-elicited macrophages revealed that the material responsible for the pro-clonogenic activity concentrated in chromatographic fractions corresponding to molecular weights (25 to 52 kDa) which are characteristic of certain cytokines. Thus, we challenged the various macrophage-conditioned media with polyclonal antibodies against IFNγand TNFα, and found that the macrophage pro-clonogenic activity was completely abolished in the presence of anti-IFNγantibodies, but only partially inhibited by anti-TNFαantibodies. This finding suggests a cooperative participation of the two cytokines to the pro-clonogenic activity of the media conditioned by Corynebacterium parvum-, BCG- or Listeria monocytogenes-elicited macrophages. This revised version was published online in July 2006 with corrections to the Cover Date.     

Biological properties associated with the enhanced lung-colonizing potential in a B16 murine melanoma line grown in a medium conditioned by syngeneic Corynebacterium parvum-elicited macrophages

A previous study by our laboratory showed that the peritoneal murine Corynebacterium parvum-elicited macrophages released into their growth medium an activity which enhanced the ability of B16-F10 melanoma cells to form experimental metastases in the lung of syngeneic mice. In the present study, we used a clone of B16-F10 line (F10-M3 cells) to investigate whether the increase in lung-colonizing potential due to the pro-clonogenic activity released by C. parvum-elicited macrophages was associated with biological properties characteristic of a metastatic phenotype. We have found that the pulmonary retention, growth rate in lung parenchyma, invasiveness through Matrigel, adhesiveness to IL-1-activated endothelium and MHC class I expression were increased in F10-M3 cells stimulated by the macrophage pro-clonogenic activity. By using an in vitro experimental protocol, the enhancement of lung-colonizing potential in the stimulated melanoma cells turned out to be a transient phenomenon as was the increase of invasiveness through Matrigel and the higher expression of MHC class I antigens. In conclusion, the melanoma cells stimulated by the pro-clonogenic activity released by C. parvum-elicited macrophages showed changes in biological parameters which are relevant to metastatic diffusion. These changes appeared as a temporary phenomenon which sustains the view that the metastatic phenotype represents a transient biological character influenced by host factors. This revised version was published online in July 2006 with corrections to the Cover Date.     

Effects of nucleus basolateralis amygdalae neurotoxic lesions on aversive conditioning in the rat

After bilateral stereotaxic administration of ibotenic acid on the n. basolateralis amygdalae, male adult rats were tested in the light-dark box apparatus to measure the time-course of the acquisition and retention of passive and active avoidance responses. The results show that after the lesions both passive avoidance and active avoidance acquisition were impaired. Passive avoidance responses were retained quite well, while active avoidance responses disappeared quickly. Conditioned freezing was almost completely absent. Thus it appears that the n. basolateralis plays a facilitatory role in all the conditioned responses which were investigated.     

Nitric oxide modulates cardiac and mast cell anaphylaxis

Anaphylaxis in the isolated guinea-pig heart was associated with a sudden release of histamine with a long-lasting release of nitrite (NO ₂ ^– ), an oxidation product of NO.N ^G-monomethyl-l-arginine (MeArg, 300 M) increased the severity of cardiac anaphylaxis, as shown by the decrease in the coronary flow and by a prolonged duration of antigen-induced arrhythmias. Concomitantly, MeArg increased the release of histamine while decreasing the release of nitrite. Sodium nitroprusside (NaNP, 10^–5–10^–4 M) reduced the severity of cardiac anaphylaxis by increasing coronary flow and shortening the duration of antigen-induced arrhythmias. Concomitantly, NaNP decreased the release of histamine while increasing the release of nitrite. In mast cells isolated from actively sensitized guinea-pigs, the release of histamine elicited by specific antigen was increased by MeArg and decreased by NaNP.In conclusion, endogenous and exogenous NO antagonizes the effect of vasoconstrictor mediators released after antigen challenge and plays a protective role in anaphylactic reactions in vitro,     

Syncope in cardiac amyloidosis and chronic ischemic heart disease: A case report

Primary systemic amyloidosis is a relatively uncommon disease characterized by the production and deposition of pathological insoluble fibrillar proteins in organs and tissues. It has been estimated that between one-third and one-half of all patients with primary amyloidosis experience clinically significant cardiac involvement. The present study reports a case involving a 77-year-old woman with ischemic heart disease who presented to the cardiology department because of syncope due to slow atrial fibrillation. Laboratory tests revealed a monoclonal spike in the gamma fraction and impairment of renal function, normocytic anemia, mild hypercalcemia, hypoalbuminemia and increased levels of beta-2 microglobulin. Suspicion of cardiac involvement was supported by the echocardiographic pattern and increased levels of troponin I and brain natriuretic peptide, along with clinical signs of heart failure and systemic amyloidosis diagnosis, confirmed by abdominal fat aspiration.     

Pediatric medial epicondyle fractures with intra-articular elbow incarceration

BackgroundIntra-articular incarceration of the epicondylar fragment occurs in 5–18 % of all cases of medial epicondyle fracture. It requires stable fixation to allow early motion, since elbow stiffness is the most common complication following medial epicondyle fracture. In this retrospective study, we report the clinical and functional outcomes and the complications that occurred following open reduction and screw fixation of medial epicondyle fractures with intra-articular fragment incarceration.MethodsThirteen children who had a fracture of the medial epicondyle with incarceration of the fragment in the elbow joint (type III) were surgically treated in our university hospital between 1998 and 2012. There were eight male and five female patients. The mean age at the time of injury was 13 years (range 9–16). Operative treatment consisted of open reduction and internal fixation with one or two 4.0-mm cannulated screws under fluoroscopic control.ResultsAll of the patients were clinically reviewed at an average follow-up of 29 months. The overall range of motion limitation was about 5° for flexion–extension and 2° for pronation–supination. The score was excellent in all patients (mean 96.3). Complications occurred in four (31 %) children: two cases of symptomatic screw head prominence, irritation with partial lesion of the distal triceps myotendinous junction in one patient, and median nerve entrapment syndrome in one patient.ConclusionsIn conclusion, open reduction and screw fixation yielded excellent clinical and functional outcomes for the treatment of medial epicondyle fractures with intra-articular fragment incarceration. However, particular attention is should be paid when treating these potentially serious injuries in order to minimize the risk of possible complications.

Level of evidence

Therapeutic IV.