Contribution of autologous blood transfusion in cardiac surgery in the adult

The use of autologous blood transfusion in cardiac surgery is still controversial. This study was prospectively designed to evaluate the haemodynamic and haematological benefits of this method, with special attention to its impact on reducing bank blood requirements. Between November 1983 and October 1984, 160 patients underwent cardiac surgery with extracorporeal circulation and were randomly assigned to two groups: group I (81 patients) was the control group and group II (79 patients) received autologous transfusion following extracorporeal circulation. Blood was withdrawn immediately after the induction of anaesthesia via a jugular catheter and stored in CPD solution at room temperature. The volume of blood removed was replaced with gelatin solutions; after bypass, blood was returned to the patient. There was no difference in systolic, diastolic or mean blood pressures between the two groups. Right atrial pressure and heart rate were not statistically different in both groups. Myocardial perfusion and myocardial oxygen consumption remained unchanged in group II compared with group I. Complete haematological evaluation was carried out before and during bypass, and thereafter daily for the first twelve days of the postoperative period. There was no significative difference between the two groups in platelet counts, fibrinogen levels, prothrombin and partial thromboplastin times. During extracorporeal circulation, mean haematocrit was 22.9 +/- 0.4% in group II and 25.3 +/- 0.5% in group I (p less than 10(-3)). The mean haematocrit time course was similar in both groups during the postoperative period and returned to preoperative value at discharge.(ABSTRACT TRUNCATED AT 250 WORDS)     

Assessment of extraocular muscles position and anatomy by 3-dimensional ultrasonography: a trial in craniosynostosis patients.

PURPOSE: To determine whether 3-dimensional ultrasonography (3D US) provides information about anatomy and position of extraocular muscles to better guide surgeons approaching strabismus in patients with craniosynostosis who often have anomalous or absent eye muscles. METHODS: The 4 rectus eye muscles were imaged using 3D US for 7 children with craniosynostosis before or after strabismus surgery. Reconstructed 3D images were interpreted as having normal or abnormal anatomy and position, based on comparison with images acquired from 6 normal eyes. Interpretation was validated against the intraoperative findings from strabismus surgery. RESULTS: A total of 34 scans from the study group were used for comparison and validation purposes. Accuracy of anatomical assessments was 85% +/- 12% (percentage +/- confidence interval) and of positional assessments was 62% +/- 16%. Sensitivity and specificity of anatomical assessments was 80% +/- 14% and 88% +/- 10%, respectively. Anatomic anomalies detected by 3D US included excessively thick, thin, scarred and fibrotic, and absent muscles. Sensitivity and specificity of positional assessments was 48% +/- 17% and 85% +/- 12%, respectively. Positional anomalies such as muscle displacement off the normal clock hour axis or posteriorly displaced insertion were also detected. CONCLUSIONS: The 3D US may have an adjunctive role in determining anatomy and position of rectus muscles in patients with craniosynostosis, although it was more accurate in assessing anatomic features rather than positional features of rectus muscles.     

Bicarbon valve - European multicenter clinical evaluation

Objective: Fifteen collaborating centers in eight countries present their pooled experience with the new Bicarbon™ bileaflet valve. Methods: Between 4/90 and 4/96, 1351 patients, 806 males and 545 females, aged 10 to 83, mean 58.4±12.4, underwent valve implantation. Operations: AVR, 726; MVR, 475; DVR, 150. Additional procedures: CABG, 211; TV repair, 64; other, 152. Results: Mortality: 67 early (seven valve related) and 56 late (40 valve related). Valve thrombosis: six obstructive, three non-obstructive; embolism: nine major cerebral, 37 other. Major bleeding: 29. Hemolysis: two clinically significant. Non-structural dysfunction: 24 paravalvular leaks, one leaflet interference. No structural failure! Endocarditis: 24. Reoperation 48: 22 non-structural dysfunctions, 14 endocarditis, seven thrombosis and embolism, five other. Estimated 5-year freedom from valve-related deaths is 97.2% for AVR and 92.4% for MVR; 4-year freedom from valve related deaths for DVR is 90.5%. Mean calculated NYHA improvement is 1.24. Conclusions: The Bicarbon mechanical prosthesis is well designed, durable, has good hemodynamic features and an acceptably low incidence of complications.     

Primary chemotherapy in the treatment of breast cancer]

Between 1980 and 1992, 457 consecutive patients with initial breast cancer entered two successive protocols combining neoadjuvant chemotherapy, hormonotherapy (tamoxifen) and locoregional radiotherapy (teleradiotherapy and boost by iridium) as exclusive locoregional treatment. Cytological diagnosis, hormone receptors, cytological grading were provided by fine needle aspiration. Both protocols included velbe, thiotepa, methotrexate, 5FU and adriamycin with some minor differences regarding the schedule of doses and their number during induction and during the consolidation phase. In both studies, over 50% patients had locally advanced breast cancer (IIb, IIIa or IIIb). Chemotherapy induced tumor regression over 50% in 91% patients of the first protocol (30% complete clinical remission CR) and in 94% patients of the 2nd protocol (40% CR): in this protocol 20 poor responders were given a rescue protocol (2 CR; 9 partial remissions). The 5 year actuarial rate of breast preservation is 94% and the 5 year actuarial rate of local relapses is 15%. The cosmetic results according to Danoff are excellent 20%, good 55%, mean 35%. Disease free survival and overall survival compare favorably to published data: they depend on TNM stages, tumor differentiation and chemotherapy induced early tumor regression.     

Percutaneous balloon dilatation of calcific aortic valve stenosis: anatomical and haemodynamic evaluation.

Two groups of elderly patients with calcified aortic stenosis were treated by balloon dilatation. In group 1, the valve was dilated just before surgical replacement of the valve. The valvar and annular changes occurring during dilatation were examined visually. In 20 of the 26 patients in this group there was no change. In the six remaining patients mobilisation of friable calcific deposits (1 case), slight tearing of the commissure (4 cases), or tearing of the aortic ring (1 case) were seen. Dilatation did not appear to alter valvar rigidity. In 14 patients (group 2) the haemodynamic gradient across the aortic valve was measured before and immediately after dilatation and one week after the procedure. Dilatation produced an immediate significant decrease of the aortic mean gradient and a significant increase of the aortic valve area. Eight days later the mean gradient had increased and the aortic valve area had decreased. Nevertheless there was a significant difference between the initial gradient and the gradient eight days after dilatation. The initial aortic valve area was also significantly larger than the area eight days after dilatation. The aortic valve gradient rose significantly in the eight days after dilatation and at follow up the gradients were those of severe aortic stenosis.     

Regulation of Ca2+ current in frog ventricular myocytes by the holding potential,c-AMP and frequency

The whole-cell patch-clamp technique was used to study the effects of holding potential and frequency on the Ca2+ current in frog ventricular myocytes. INa was blocked by TTX, and ica was activated with depolarizing clamps from different holding potentials. Variation of the holding potential revealed three new effects on ica: (1) At -40 mV iCa declined with a time constant of 15 min, while at -90 mV, this irreversible decline (run down) in iCa did not occur. (2) The decline of iCa at -40 mV was biphasic: run down was preceeded by a slow inactivation with a time constant of 40 s, which was reversible upon returning the holding potential to -90 mV. (3) Increasing the frequency of the clamp pulses from 0.1 to 1 Hz led to a rapid decline of iCa when the holding potential was positive to -60 mV, but at -90 mV had either no effect or increased iCa by 35%, if c-AMP was included in the dialyzing solution. On the other hand, c-AMP did not alter the time course of the run down and the slow inactivation. Replacement of extracellular Ca2+ by Ba2+ markedly slowed iCa kinetics, but did not change the very slow inactivation or the frequency-induced enhancement of iCa. Injection of c-AMP led to a transient increase of iCa. The phosphodiesterase inhibitor theophylline enhanced the amplitude of the transient and slowed its decay. This effect was mimicked by increased frequency. It is concluded that frequency-induced enhancement of iCa is highly dependent on the holding potential, independent of Ca2+, and may involve elevation of the intracellular level of c-AMP via inhibition of phosphodiesterase activity. The new type of very slow inactivation is probably under direct voltage control and independent of Ca2+ and c-AMP.     

Exercise- and insulin-stimulated muscle glucose transport: distinct mechanisms of regulation.

In mammals, skeletal muscle is the primary target for the stimulation of glucose transport by a variety of activators. These include the hormone insulin and stimuli which increase energy demand such as exercise, hypoxia, and challenges to the oxidative chain. While it is known that both stimuli rapidly elevate glucose uptake into muscle by signalling the translocation of glucose transporters from intracellular stores to the plasma membrane, there are numerous contrasts between energy stressors and insulin in their mechanisms of glucose transport activation. Exercise and insulin recruit distinct intracellular pools of glucose transporters in skeletal muscle and the maximal effects of contraction and insulin are additive. Activation of phosphatidylinositol 3-kinase (PI3-K) is utilized by insulin to induce glucose transporter translocation, but does not participate in the responses to exercise or hypoxia. These findings suggest that energy stressors utilize different mechanisms from insulin to increase glucose influx; however, how these factors elicit their response is not clear. This review will summarize our current knowledge of these alternative pathways of glucose transport regulation. Emphasis is placed on the use of the mitochondrial uncoupler dinitrophenol to investigate mediators of this alternative signalling pathway in L6 muscle cells, a line used to characterize physiological responses in muscle such as glucose transport.