The Self-Assembling Peptide P11-4 Prevents Collagen Proteolysis in Dentin.

The major goal in restorative dentistry is to develop a true regenerative approach that fully recovers hydroxyapatite crystals within the caries lesion. Recently, a rationally designed self-assembling peptide P11-4 (Ace-QQRFEWEFEQQ-NH2) has been developed to enhance remineralization on initial caries lesions, yet its applicability on dentin tissues remains unclear. Thus, the present study investigated the interaction of P11-4 with the organic dentin components as well as the effect of P11-4 on the proteolytic activity, mechanical properties of the bonding interface, and nanoleakage evaluation to artificial caries-affected dentin. Surface plasmon resonance and atomic force microscopy indicated that P11-4 binds to collagen type I fibers, increasing their width from 214 ± 4 nm to 308 ± 5 nm ( P < 0.0001). P11-4 also increased the resistance of collagen type I fibers against the proteolytic activity of collagenases. The immediate treatment of artificial caries-affected dentin with P11-4 enhanced the microtensile bonding strength of the bonding interface ( P < 0.0001), reaching values close to sound dentin and decreasing the proteolytic activity at the hybrid layer; however, such effects decreased after 6 mo of water storage ( P < 0.05). In conclusion, P11-4 interacts with collagen type I, increasing the resistance of collagen fibers to proteolysis, and improves stability of the hybrid layer formed by artificial caries-affected dentin.

Arbovirus studies in Angola: Serological survey for antibodies to arboviruses.

A serological survey was made comprising 4,590 human sera collected in 16 areas of Angola, in order to determine the distribution of arboviruses. The results obtained with the hemagglutination inhibition (HI) test have shown that the activity of the arboviruses is more prevalent in northern Angola, where a larger number of sera reacted in the HI test against group A and B arboviruses (7% and 32..6%, respectively). Several sera with HI reactions against Bunyamwera, group C, and Rift Valley fever viruses were also found.

Early surgical results in the treatment of endomyocardial fibrosis. A Brazilian cooperative study.

This report summarizes the surgical experience and early results obtained at four surgical centers in the northeast and south of Brazil. From December 1977 to September 1986, 95 operations were performed on 93 patients, ages 11-59. Bilateral lesions occurred in 42 patients, right lesions in 39, and left lesions in 12. Ventricular decortication and removal of thrombi were performed in all. In right-sided lesions, the tricuspid valve was substituted by a bioprosthesis in 34 cases, and substituted by a tilting disk valve in 1 case. In 4 patients, the valve could be preserved. The left-sided lesions led to valve substition by a bioprosthesis in 11 cases, and preservation of the valve in 1. The bilateral lesions needed bioprosthesis in the mitral position in 37 patients, and a disk valve in 2. In these 39 instances, the valvular procedure was insertion of a tricuspid bioprosthesis. Three tricuspid and three mitral plasties were performed. The overall mortality was 20% (26.2% for bilateral lesions, 14.6% for the right-sided lesions, and 20% for the left-sided lesions). The main cause of death was low cardiac output. Aside from a variable degree of right and left ventricular failure, many other non-fatal complications clouded the postoperative course. Complete AV blocks occurred in 10 cases, with the need for permanent pacing in 7 survivors. The mortality and morbidity in the present series is in keeping with the results reported in current literature. Regarding the advanced stage of their patients' disease, the authors agree with the recommendation for earlier surgical intervention.

Long-term results of mammary artery implants.

Eighty out of eighty-six patients (93%) with mammary artery implants were followed postoperatively for an average of three and a half years. The immediate mortality rate was 7% (6 cases), and the late mortality was 6% (5 cases). All had angina preoperatively. Twenty-four had a history of myocardial infarction and thirty-one were on limited physical activity, because of the pain. After surgery, thirty-three (45%) became asymptomatic. The angina improved significantly in thirty-five (47%) and remained unchanged in six (8%). Improvement in ventricular repolarization on ECG was observed in 69% of the patients. Postoperative cineangiography was performed in twenty-three patients; thirteen with single and ten with double implants. Out of the total of thirty-three implants, four (12%) were obstructed and twenty-seven patent (82%); twenty were in two cases of double implant, only one implant could be satisfactorily studied effectively functioning (61%). No obstructions were seen in the single implants. Non functioning implants were found in five (38%) of the thirteen single implants and in two of the twenty double ones (10%). The highest incidence of obstruction or non-functioning implants occurred in the group that did not show improvement (43%). This rate fell to 40% in the group that had some improvement and to 29% in those that were completely asymptomatic. Twelve of the eighteen patent mammary implants (67%) on the anterior wall of the left ventricle and eight of nine (89%) on the lateroinferior wall, established collateral circulation to the coronaries. Indication for surgery was considered satisfactory for nineteen out of the twenty-three patients and poor in four. There were two cases of obstruction of the implant (7%) in the group where surgery was correctly indicated and three of the twenty-three (11%) patent implants were non-functioning. Clinical improvement of the angina occurred in 84% in the first group and 50% in the other. In conclusion, this technique of indirect revascularization of the myocardium is valid for patients with severe diffuse lesions of the coronaries with a collateral network and preserved myocardial contractility.

Bilateral carotid endarterectomy combined with myocardial revascularization during the same surgical act.

The best surgical approach for the treatment of patients with severe cerebral artery disease and simultaneous serious coronary artery disease still remains controversial. In this report we present a case of a 72-year-old female patient admitted to the hospital with unstable angina. Triple coronary artery obstructive disease and severe bilateral carotid artery stenosis were diagnosed. A combined, simultaneous surgical procedure was performed. After total circulatory by-pass with a membrane oxygenator, the patient's body temperature was lowered to 32 degrees C. During the cool-down period, three proximal anastomoses of segments of autologous saphenous veins were performed in the ascending aorta. Immediately afterwards, bilateral carotid endarterectomy was performed, followed by three distal anastomoses to coronary arteries. The patient showed a satisfactory post-operative outcome. It was concluded that the combination of moderate hypothermia, hemodilution with appropriate hemodynamic control, as used in this patient, was an effective method of cerebral protection. The simultaneous approach of carotid endarterectomy and coronary artery by-pass surgery should be seen as a safe option for the treatment of this type of patient.

[Partial median sternotomy in H. A new approach for cardiac surgery]. / Esternotomia parcial mediana em H. um novo acesso para a cirurgia cardíaca.

PURPOSE: To present our results with the minimally invasive thoracotomy (MIT) in patients with valve disease and to describe a new type of thoracotomy. METHODS: Twenty-five patients with valve disease as the major cardiac problem were operated during a five month period. Two types of incisions were used: one in an inverted-T fashion and another in a H fashion. Fourteen patients were submitted to an inverted-T incision and eleven to a H incision. In 24% of the patients reoperation was being performed. RESULTS: The incisions ranged from 7.5 to 11 cm (mean 9.1 cm), mean ICU stay was 31 h and hospital stay 4.8 days. In all but one patient the operation could be adequately in performed through the MIT, in only one patient total sternotomy had to be performed. CONCLUSION: The MIT may have some advantages such as, better aesthetic results, less pain and more sternal stability. These factors may improve early extubation and decrease hospital stay. The H type incision allows an adequate exposition of the most central part of the chest and all heart valves with adequate exposure. This technique led to no complications during reoperations and we believe it to be as safe as the total sternotomy.