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Biomedical subjects

P Bardos

Publications and source records attributed to P Bardos.

At least 109 records · Page 6Linked to original sources

New developments in medical-surgical treatment of acute myocardial infarction.

Selective intracoronary thrombolysis with streptokinase was successful in 72 of 84 (86%) patients admitted to the hospital with definitive signs of acute transmural myocardial infarction due to complete occlusion of either the left anterior descending coronary artery, the right coronary artery, or the circumflex artery. The average time between onset of acute symptoms and medically induced reperfusion was 241 +/- 90 minutes (SD). Reperfusion resulted in prompt relief of pain, regression of cardiogenic shock, and normalization of electrocardiograms. Follow-up treatment was either medical or surgical. The 32 medically treated patients had a high reocclusion rate, with 6 fatal (19%) and 9 nonfatal (28%) reinfarctions. In order to the reduce the risk of reinfarction, additional simultaneous transluminal balloon angioplasty was done in a recent series of patients with stenoses accessible to this technique. The best early and long-term results were achieved in 17 patients who underwent coronary artery bypass grafting within three days after successful thrombolysis. There was no operative mortality, and subsequent bleeding has not been a problem. It is concluded that early operation is the treatment of choice in all patients suitable for such intervention who have undergone successful intracoronary thrombolysis within 4 hours after onset of acute myocardial infarction. Late coronary bypass operation should be reserved for symptomatic patients who have definitive signs of infarction in spite of successful thrombolysis.

Aged↗

Genetic control of murine antibody-dependent cell-mediated cytotoxicity. Partial identity with the genetic control of NK activity.

We have observed that the intensity of the direct antibody-dependent cell-mediated cytotoxicity (ADCC) response after an inoculation of foreign tumour cells varies with the strain of mice studied. The inoculation of a human lymphoblastoid cell-line into CBA/J, BALB/c, or DBA/2 mice gives rise to a good cytotoxic response by the host K cells armed with specific antibodies. In contrast, A/J, B10.A, C57BL/6 and B10.S mice respond poorly under the same conditions. The high response is dominant in F1 hybrids between high and low responders and is also expressed among F2 backcrosses with the H-2 phenotype of low responders, suggesting that non-H-2 genes are also implicated in the regulation of ADCC. The genetic control is not exerted at the level of antibody secretion but at that of K-cell activity, since sera from high or low responders are equally effective in arming an ADCC reaction, whereas K cells from low-responder strains are less efficient than those from high-responder strains. The natural killer (NK) activity of the same strains has been screened. The results show a good correlation with some high- and low-responder strains, such as CBA and DBA/2 or A/J and SJL, respectively, but not with C57BL/6, B10.S or B10.A strains. Thus, in addition to common genes controlling both lytic functions, there are specific genetic factors influencing the balance between NK and K cells. These findings confirm the general view that NK and K cells represent only partially identical subsets.

Animals↗

[Ventricular septal defect in acute myocardial infarction].

Ventricular septal rupture is the fourth-common cause of death after cardiac arrhythmia, acute congestive failure and rupture of the cardiac wall in acute myocardial infarction. Generally it can be easily diagnosed by a systolic jet sound in the 4th and 5th intercostal space parasternally on the left side. Differential diagnostic difficulties occur in the acute phase of infarction regarding papillary muscle rupture. Myocardial rupture does not occur immediately after the onset of the pectanginous state and not within the first day of illness, but generally within the first week. Vasodilatory treatment permits only short-term stabilisation of vascular problems, however, time is made available for diagnostic measures, usually catheterisation of both sides of the heart and coronary angiography. Immediate operation and occlusion of the defect, if necessary accompanied by a saphenous vein bypass, is presently considered treatment of choice. Out of the three patients with this complication the ruptured site could be occluded surgically in two, one of whom had severe cardiogenic shock. Shock symptoms regressed immediately and the postoperative course was unremarkable. In the third patient no operation was performed due to his age of 77 years and general vascular sclerosis. He died of cardiogenic shock 11 hours after admission to hospital.

Aged↗

Repair of complete atrioventricular canal in early childhood.

From November 1977 to January 1981, 10 consecutive patients underwent intracardiac repair of the complete atrioventricular canal at our institution. Ages ranged from 14 months to 4.5 years (mean age 20 months). Four patients were predominantly of type A, while 6 were predominantly of type C according to Rastelli's classification. Three patients had associated cardiac anomalies (2 tetralogy of Fallot and one parachute mitral valve). Standard repair and correction of the associated anomalies were performed under cold cardioplegic cardiac arrest and deep hypothermia with low-flow perfusion or circulatory arrest. Two patients died early postoperatively in severe renal failure and one died 6.5 months postoperatively in cardiac failure due to progressive mitral valve incompetence. One patient, with parachute mitral valve, was reoperated and the mitral valve was replaced because of persistent mitral insufficiency. The patients were followed up for a period of 4 to 35 months (mean 14 months) with a total of 112 patient months. The result of the operation was very good and all patients with retarded growth curve preoperatively showed a marked acceleration of their growth curve after operation. The operative results in this group of patients are independent of age and weight at the time of operation but appear to be influenced by associated cardiac anomalies and by the quality and quantity of atrioventricular valve tissue available for reconstruction.

Age Factors↗

Modulation of mouse natural killer cell activity by the serum thymic factor.

After mice had been treated with serum thymic factor (FTS), we observed an increase or a decrease in the NK activity, depending on the duration of treatment and mouse strain: an increase of C57BL/6, BALB/c, A, and nu/nu, and a decrease for NZB and CBA mice. The fact that treatment of C57BL/6 mice with FTS produces the same effects as thymectomy--that is, an increase--on the NK activity and returns the augmented NK activity of thymectomized mice to normal levels suggests that FTS has multiple effects with different results depending on the level of differentiation of the target cells. Different mechanisms of action of FTS on NK cells are discussed.

Animals↗

Morphometric investigations in mitral stenosis using two dimensional echocardiography.

A method is proposed for comparing the orifice size and the morphology of stenotic mitral valves, removed intact at the time of replacement, with the preoperative two dimensional echocardiographic cross-sections. The excised mitral valve apparatus is suspended on a specially constructed mounting. To avoid shrinkage the orifice is stabilised with an airfilled balloon. A radiography is taken directing the x-ray beam perpendicular to the valve orifice. In 40 of 51 patients this method provided the means of relating the echocardiographic cross-sections to the morphology of the valve. Planimetry of the valve area compared favourably with the postoperatively determined orifice size. Agreement was found in 34 of 40 patients in orifice shape between preoperative echocardiograms and x-rays of th excised valve. The relation between intraoperative estimation of size of the valve, using dilators with known diameters, and the postoperative results was less favourable. Areas of calcification were identified on echocardiography as dense conglomerate echoes. In 30 patients (75%) the localisation of calcium deposits and in 67% the degree of calcification was in agreement with the x-rays of the valve taken after operation. In addition to determination of the area, two dimensional echocardiography allows detailed studies of the stenotic valves, and is of particular importance for planning operative treatment.

Adult↗

Percutaneous transluminal coronary angioplasty immediately after intracoronary streptolysis of transmural myocardial infarction.

Percutaneous transluminal coronary angioplasty (PTCA) was performed in 21 patients with acute myocardial infarction (AMI) treated by intracoronary infusion of streptokinase within 8 hours after the onset of symptoms. Streptolysis therapy began a mean of 3.6 +/- 1.2 hours (+/- SD) after the onset of symptoms. The vessel was occluded in 14 patients and highly stenosed in seven. After the infusion of 67,300 +/- 63,200 IU of streptokinase over 26.1 +/- 21.5 minutes, patency of the occluded vessels was reached. PTCA as performed 20-60 minutes after the end of streptokinase treatment in 19 patients and 24 and 31 hours after treatment in two patients. The dilation was successful in 17 patients (81%). The degree of vessel obstruction was reduced from 90.2 +/- 7.3% to 58.6 +/- 19.5% (area method) and from 71.4 +/- 12.4% to 39.2 +/- 19.7% (diameter method). The improvement was 31.5 +/- 18.4% and 32.2 +/- 19.3%, respectively. No reocclusion was induced by PTCA. Twenty patients were discharged. One died during hospitalization; at autopsy, the treated vessel was still patent. During the follow-up period, two reinfarctions and one asymptomatic reocclusion occurred. The clinical findings during the hospital course and the follow-up period were compared with those of a control group of 18 patients with AMI and comparable coronary stenoses who were treated only with streptokinase infusion. Four of these patients had a reinfarction during the hospital course, and three died during the follow-up period. PTCA can be performed safely and successfully immediately after intracoronary infusion of streptokinase in patients with AMI. By reducing the subtotal stenosis, this treatment contributes to the reperfusion of the ischemic myocardium, diminishes the risk of a reocclusion and seems to improve the prognosis.

Adult↗

Treatment of unstable angina pectoris with percutaneous transluminal coronary angioplasty (PTCA).

Percutaneous transluminal coronary angioplasty (PTCA) was performed in 40 patients (34 male, 6 female; 51.0 +/- 8.5 years) with the typical clinical picture of unstable angina. All had a short history of pain (2.9 +/- 2.0 months), angina at rest, transient ST and/or T wave changes during this period, and little or no enzyme elevations. The patients had a total of 41 stenoses (39 single, one double; one main-stem, 26 left anterior descending, 14 right coronary artery). The degree of the stenoses was 95.5 +/- 4.9% (area method) and 81.8 +/- 10.7% (diameter method). PTCA was successfully performed in 26 cases (63%), reducing the stenoses to 61.5 +/- 12.4% (area method) and 39.1 +/- 10.0% (diameter method). One patient (2.5%) received an immediate bypass operation because of an acute vessel occlusion. Eleven of the 14 not successfully treated patients received an aortocoronary bypass within the next three to 35 days. All still had symptoms of unstable angina. Three patients refused operation. Their treatment consisted of nitroglycerin, beta-blockers and nifedipin. Seventeen of the 26 successfully treated patients were restudied after 4.9 +/- 1.7 months. The degree of stenosis had risen to 69.2 +/- 17.4% (area method). While the stenoses in 12 patients were equal or less than before PTCA, stenosis recurred in five cases. Two patients were successfully retreated. PTCA can be performed with a good early success rate and a low concentration rate in patients with unstable angina. Relief of pain and improvement of blood supply to the jeopardized myocardium can be provided immediately and with a limited amount of expense. The method can therefore be regarded first-stage treatment in such patients.

Adult↗

Neocortical lateralization of NK activity in mice.

The natural killer (NK) reactivity of mouse spleen cells is controlled by the left brain neocortex and not by the right symmetrical brain area. The finding strongly suggests direct relationships between the central nervous system and the immune system, both involved in biological adaptation for the maintenance of homeostasis and body integrity in relation to the external environment.

Animals↗

Detection of left atrial thrombi by echocardiography.

A group of 111 patients with mitral valve disease was studied by M-mode and two-dimensional echocardiography. Five left atrial thrombi were demonstrated, two of which had probably been the source of previous embolic events. Two-dimensional echocardiography was superior to M-mode in providing spatial orientation. Using multiple cross-sections the exact localisation and the size of the thrombus formation could be estimated. Thrombus localisations at the upper, lateral, and septal atrial walls, normally inaccessible to the single-beam technique, were successfully imaged. Even two-dimensional echocardiography, however, constitutes an imperfect method. By comparison with the findings at surgery only one-third of confirmed thrombi could be detected non-invasively. According to their localisation seven clots in the appendage were missed by the ultrasound method. One further thrombus fixed to the upper left atrial wall near the entrance of the upper pulmonary veins was also undetected by echocardiography. Despite these limitations, the information provided by echocardiography can be most helpful in patient management. M-mode, in combination with two-dimensional echocardiography, is therefore recommended in all patients with mitral stenosis before diagnostic or therapeutic procedures are undertaken.

Adult↗

Two-dimensional echocardiographic diagnosis of papillary muscle rupture.

A 69-year-old man developed a rupture of the papillary muscle on the fifth day of acute posterior myocardial infarction. The two-dimensional echocardiographic features of ruptured papillary muscle included (1) mobile mass of echos attached to normal chordae tendineae in the left ventricle, (2) absent tip of papillary muscle, and (3) mitral valve prolapse. Noninvasive, two-dimensional echocardiography can reveal correct diagnosis of ruptured papillary muscle suspected clinically.

Acute Disease↗

The cell populations mediating natural killing-(NK) and antibody-dependent cell-mediated cytotoxicity are only partially identical.

A cold target inhibition assay has been used to investigate the relationship between the effector cells responsible for NK and ADCC activity. Two models of ADCC have been studied in parallel with NK, one involving in vivo armed effector cells and the other involving normal effector spleen cells tested on antibody-precoated target cells. Bivalent effector cells active in ADCC and NK as well as monovalent NK cells and monovalent FcR-positive ADCC killer cells appear to exist concomitantly. However, the variability from experiment to experiment of the blocking efficiency displayed by the heterologous cold targets, suggests that the proportions of monovalent to bivalent cells may vary between batches of mice depending on their immunological status at the time of the test. This should be taken into careful consideration when interpreting the results of this type of investigation.

Animals↗

[Electrode fracture in pacemaker patients (author's transl)].

Electrode fracture is a serious late complication of pacemaker implantation. This complication was observed in 33 patients within 3 years whereby the interval between electrode implantation and fracture was on average 35 (12--113) months. The cause lay partly in the electrodes themselves--in all cases singly wound spiral electrodes--and partly in technical deficiencies in the extrathoracic loop formation. Attention is drawn to the fact that fracture has never occurred in the Elema electrode type 588 used routinely by the authors.

Adult↗

Improved technique in permanent atrial pacing.

At the present time, the relatively high atrial stimulation threshold and the low and often unstable P wave amplitude are the main concerns in atrial pacing. As a further contribution to the solution of this problem we used a screw-in atrial lead in 16 patients. During the implantation, atrial mapping was performed in order to establish the position with the best electrical performance. The acute threshold for voltage at a pulse duration of 1 ms averaged 0.49 +/- 0.18 Volt. The acute peak-to-peak P wave amplitude averaged 4.6 mV +/- 1.3. No complication occurred at the time of the implantation. Follow-up periods averaged 12 months. No dislocation or bleeding was observed during a follow-up period of up to 28 months. Using this lead together with intraoperative atrial mapping, it is possible to achieve an acute strength-duration relationship in the atrium at a level similar to that in the ventricle. The results of this study demonstrate that intraoperative mapping is an important stein in enhancing the safety margins and long-term performance of atrial pacing.

Action Potentials↗