Factors affecting Saccharomyces cerevisiae ADH2 chromatin remodeling and transcription

The chromatin structure of the Saccharomyces cerevisiae ADH2 gene is modified during the switch from repressing (high glucose) to derepressing (low glucose) conditions of growth. Loss of protection toward micrococcal nuclease cleavage for the nucleosomes covering the TATA box and the RNA initiation sites (-1 and +1, respectively) is the major modification taking place and is strictly dependent on the presence of the transcriptional activator ADR1. To identify separate functions involved in the transition from a repressed to a transcribing promoter, we have analyzed the ADH2 chromatin organization in various genetic backgrounds. Deletion of the CCR4 gene coding for a general transcription factor impaired ADH2 expression without affecting chromatin remodeling. Growing yeast at 37 degrees C also resulted in chromatin remodeling at the ADH2 locus even under glucose repressing conditions. However, although this temperature-induced remodeling was dependent on the ADR1 protein, no ADH2 mRNA was observed. In addition, inactivating RNA polymerase II (and therefore, elongation) was found to have no effect on the ability to reconfigure nucleosomes. Taken together, these data indicate that chromatin remodeling by itself is insufficient to induce transcription at the ADH2 promoter.

The pericardium reinforced suture annuloplasty: another tool available for mitral annulus repair?

From May 1985 to May 1992, 169 patients underwent surgery for mitral valve repair. In 87% of these patients, the valve reconstruction involved the mitral annulus. At the beginning, in an effort to preserve systolic movement of the annulus and avoid the implant of prosthetic materials inside the heart, we mainly used simple suture annuloplasty in 66 patients. When we reoperated upon three patients only a few months after reconstruction of the mitral valve for a dehiscence of the suture annuloplasty, we decided to perform ring annuloplasty with the Carpentier ring in 23 patients. Though we have not seen any problems with the Carpentier ring in our series, we performed a suture annuloplasty reinforced with a strip of autologous pericardium to eliminate all prosthetic material. Since introducing this technique in 1989, we have used this annuloplasty in 58 patients. We have not observed any dehiscence of the suture or other complications related to this procedure. Three patients with a pericardial annuloplasty underwent reoperation for other reasons; the autologous pericardium was perfectly attached to the annulus, covered by a smooth layer of fibrous tissue without calcification. After this encouraging initial experience, we believe that long-term follow-up is necessary to confirm that autologous pericardium is an effective method of mitral annulus repair.

[Ultrasonic decalcification of the aortic valve. Initial experience]

We report our initial experience in 2 patients with degenerative calcific aortic stenosis who underwent ultrasonic debridement of the aortic valve. Compared with preoperative studies, doppler echocardiographic and hemodynamic evaluation before hospital discharge revealed a reduction in the mean aortic valve pressure gradient (80 and 65 mmHg to less than 10 mmHg). There was no change in aortic regurgitation grade. Follow-up doppler echocardiographic evaluation at four and six months showed no changes in gradient or regurgitation in the comparison to the postoperative data. Long-term results will show the convenience to attempt or not ultrasonic salvage of the native aortic valve in severe calcific stenosis.

The replacement of the ascending aorta and aortic valve with a new design composite graft: a six-year experience

The problems encountered in coronary artery reattachment when the ascending aorta and aortic valve are replaced with a composite graft induced Gallucci and one of the authors to develop a new aortovalvular prosthesis in clinical practice. The unique transverse ovoidal shape of this graft is intended to conform to the natural aortic root and facilitate the coronary anastomoses and minimize bleeding. We present our 6-year experience with 56 patients operated upon with this prosthesis. In all patients we were able to connect the coronary arteries directly to the graft without complications including hemorrhage or distortion of the coronary ostia. The survivors were evaluated with chest X ray, two-dimensional echocardiography, and conventional or digital subtraction angiography to detect the presence of pseudoaneurysms at the site of the coronary anastomosis, reported by others that have used the composite graft technique. The notable absence of this complication in our patients at a mean follow-up of 41 months (range 3-71) documents that this ovoidal composite graft is a reliable tool in the treatment of aortic root pathology.

Calcified constrictive pericarditis. Ultrasonic debridement

A case of complete debridement of a calcified pericardium in a patient with constrictive pericarditis is reported. The use of an ultrasonic surgical aspirator facilitated disintegration of calcium without damaging the adherent epicardium and myocardium.

Efficacy and safety of predeposit blood autodonation in 500 cases of myocardial revascularization

Since 1985 all patients scheduled for coronary artery bypass grafting have been evaluated for admission to a program of predeposited blood autodonation. From a total of 816 consecutive patients, 505 were admitted to the program (group 1). The other 311 (group 2) were excluded on the basis of one or more of the following criteria: 1) emergency surgical indication, 2) hemoglobin less than 12 g/dl, or 3) uncontrolled angina or clinically manifest cardiac failure. Postoperative use of homologous blood products was required by 16% of the group 1 and 44% of the group 2 patients (p less than 0.001). Altogether 597 patients (73%) had no contact with homologous blood products. There was no intergroup difference in the incidence of postoperative complications. Non-A, non-B hepatitis developed in three group 1 and four group 2 patients. Its incidence was 0.9% among all discharged patients and 3.2% of the homologous blood recipients. The findings emphasize the safety and value of the autodonation with predeposit program in significantly reducing the requirement for homologous blood in coronary artery bypass grafting.

Psychosocial outcome one year after heart surgery. A prospective study

Ninety-nine of 118 patients receiving cardiac valve replacements (n = 55) or coronary artery bypass grafts (n = 44) were studied before surgery and again one year after surgery. Psychological, social, and physical variables were assessed. For the 19 subjects not returning for follow-up, medical data collected by their general practitioner were available. The physical results of surgery were good, with over 90% of the patients showing improvement. Mean scores for psychological distress and quality of life improved; however, a bad psychosocial adjustment was present in about 25% of patients at follow-up. Bad psychosocial adjustment was not correlated with surgical results. The preoperative variables most predictive of poor psychosocial outcome were high scores in the general hypochondriasis and irritability subscales of the illness Behaviour Questionnaire, bad psychological adjustment characterized by high anxiety, depression, and global scores on the Symptom Distress Checklist, and ischemic rather than valvular heart disease.