Biomedical subjects

C Bruch

Publications and source records attributed to C Bruch.

At least 37 records · Page 2Linked to original sources

PubMed1999

[Analysis of mitral annulus excursion with tissue Doppler echocardiography (tissue Doppler echocardiography = TDE). Noninvasive assessment of left ventricular, diastolic dysfunction].

BACKGROUND: Mitral inflow velocity, deceleration time, and isovolumic relaxation time recorded by Doppler echocardiography have been widely used to evaluate left ventricular diastolic function but are affected by age, heart rate, loading conditions, and other factors. The diastolic mitral anulus velocity assessed by tissue Doppler echocardiography (TDE) was suggested to provide additional information about LV relaxation less affected by filling pressures. AIM OF THE STUDY: This study was designed to assess the clinical utility of mitral anulus velocity in the evaluation of left ventricular diastolic function. PATIENTS AND METHODS: Three groups of patients with a systolic ejection fraction > 45% were separated: 10 normal volunteers (60 +/- 10 y, CON group), 15 asymptomatic patients with known coronary artery disease (60 +/- 11 y, CAD group) and 15 patients with long-term arterial hypertension and heart failure symptoms (58 +/- 9 y, HYP group). The mitral inflow profile (E, A, E/A) was measured by pulsed Doppler, and the deceleration time (DT) and the isovolumic relaxation period (IVRT) were calculated. Systolic, early, and late diastolic velocities of the septal mitral anulus (ST, ET, AT, ET/AT) were assessed by pulsed TDE. All study subjects had invasive measurements of left ventricular end diastolic filling pressures during left heart catheterization. RESULTS: In the AH group, ET (6.9 +/- 4.8 cm/s) and ET/AT (0.71 +/- 0.28) were reduced compared to the CON group (11.7 +/- 4.7 cm/s and 1.11 +/- 0.36, p < 0.05, respectively) and the CAD group (8.9 +/- 5.4 cm/s and 0.85 +/- 0.26, respectively, p = ns). The groups did not differ with respect to the mitral E/A ratio, the deceleration time and the isovolumic relaxation time. LVED in the HYP group (16 +/- 8 mm Hg) was elevated compared to the CON group (8 +/- 3, p < 0.05) and the CAD group (12 +/- 6 mm Hg, p = ns). No correlation was found between ET and LVED (r = 0.26). When the combination of mitral E/A ratio > 1 with LVED > or = 15 mm Hg was classified as pseudonormalization, the pseudonormalization could be identified by a peak early diastolic mitral anulus velocity (ET) < 7 cm/s and an ET/AT ratio < 1 with a sensitivity of 77% and a specificity of 88%. CONCLUSIONS: The early diastolic mitral anulus velocity assessed by TDE (ET) is a preload-independent index of LV relaxation. TDE permits the detection of diastolic dysfunction in patients with a pseudonormal mitral inflow and elevated filling pressures.

Adult↗

PubMed1999

Tissue Doppler imaging (TDI) for on-line detection of regional early diastolic ventricular asynchrony in patients with coronary artery disease.

Diastolic filling of the left ventricle is often impaired in patients with coronary artery disease (CAD) in the absence of systolic wall motion abnormalities or previous myocardial infarction. The current study was designed to assess the ability of tissue Doppler imaging (TDI) for on-line detection of regional diastolic wall motion abnormalities to identify CAD in patients with preserved systolic function. 20 normal subjects (age 51 +/- 13 years) and 17 CAD patients with normal systolic function and > or = 70% luminal narrowing of the LAD (age 56 +/- 11 years) were included. Coronary anatomy was unknown to the echocardiographer. In the parasternal short axis and the apical 4-chamber-view, peak tissue velocities of the anterior/inferior and the midseptal/midlateral LV segments during rapid ejection (RE), isovolumic relaxation (IR), rapid filling (RF) and atrial contraction (AC) were analyzed by color-M-Mode-TDI. In the apical view, in 13 of 35 (37%) patients with adequate recordings, myocardial asynchrony was detected during IR: while the septum was moving inwards (red color-coding), the lateral wall was moving outwards (blue/green coding). In the remaining 22 patients (63%) a slow, synchronous outward motion of septum and lateral wall with homogeneous color-coding (blue/green) was seen. Unblinding of the coronary status revealed a critical LAD stenosis in all 13 patients (100%) with myocardial asynchrony. Analysis of midseptal peak velocities during IR revealed positive velocities (1.22 +/- 1.64 cm/s) in CAD patients and negative velocities (-1.39 +/- 0.81 cm/s) in normal subjects. Thus, TDI allowed for the on-line detection of early diastolic asynchrony in 13 of 16 (82%) patients with critical LAD-narrowing. Due to the rapid assessment of regional wall motion abnormalities, TDI might help to identify CAD in patients with normal systolic function.

Aged↗

PubMed1998

[Aortic rupture after blunt chest trauma. Rapid diagnosis using transesophageal echocardiography when radiographic and computed tomographic findings are unclear].

HISTORY AND CLINICAL FINDINGS: A 37-year-old woman who was not wearing a seat-belt while driving a car had a head-on collision at 70 km/h. On arrival of the emergency physician she was awake and responsive but complained of pain with bruising over the sternum and the epigastrium. Pressure on the sternum was painful. Arterial pressure was 95/60 mm Hg, heart rate 112/min. On admission the heart sounds were unremarkable and peripheral pulses normal. Vesicular sounds were heard over both lungs. In addition to multiple facial abrasions voluntary movements were impaired and the right knee-joint was swollen. INVESTIGATIONS: The ECG showed sinus tachycardia (103 beats/min) with left axis deviation, but was otherwise unremarkable. Initially the haemoglobin was 12.6 g/dl with normal white cell and platelet counts. Clotting tests, serum transaminases, creatine kinase, lactate dehydrogenase and other routine laboratory tests were within normal limits. TREATMENT AND COURSE: Because the haemoglobin level had fallen to 7.7 g/dl within the first 4 hours erythrocytes concentrate was infused. The chest radiogram and subsequent computed tomography showed a mediastinal and paraaortic haematoma of unclear origin. Transoesophageal echocardiography (TEE) demonstrated rupture of the descending aorta with free floating intraluminal parts of the intima in the isthmal region, just distal to the origin of the left subclavian artery, which was not occluded. Colour Doppler echocardiography revealed abnormal flow into mediastinal and paraaortic tissues. At operation the echocardiographic findings were confirmed and part of the descending aorta was replaced by a 3 cm dacron tube during an aortic crossclamping time of 37 min. The patient was discharged after a postoperative stay of average length, during which her other injuries were treated. CONCLUSION: After blunt thoracic or deceleration trauma earliest possible TEE is indicated, because it can at once provide details of extent and degree of injury to heart and/or aorta.

Accidents, Traffic↗

PubMed1998

[Improved structure identification with tissue Doppler echocardiography].

Tissue Doppler echocardiography (TDE) has been shown to be of particular value in patients with impaired myocardial function. Recently, the technique was successfully employed to localize the ventricular insertion of accessory atrioventricular pathways. The identification of abnormal cardiac structures is coming up now as a new field of clinical interest. The purpose of this study was to differentiate anomalous cardiac and aortic from native structures by physical properties of tissue motion using transesophageal TDE. Characteristic motion patterns of anomalous structures have not been described in detail and tissue Doppler findings have not been associated with clinical features up to now. Forty consecutive patients were included after anomalous cardiac or vascular structures had been detected by conventional transesophageal echocardiography (TEE). A control group consisted of 20 subjects. Rapidity of diagnosis in anomalous structures was divided into 3 categories, and TDE signals were related to particular pathology by a blinded, 2nd observer. Three different motion patterns could be defined: incoherent motion due to free oscillation of an anomalous structure which is independent of the surrounding tissue (Figure 1b); coherent motion with a phase difference meaning that motion depends on the motion of the surrounding tissue but is out of phase (Figure 2); concordant motion showing no difference in direction, velocity, or phase of motion compared with the surrounding tissue. Incoherent motion was present in endocarditic vegetations, 4th degree aortic plaques, Chiari network, valvular prolapse, intracavitary tumors, and freely oscillating thrombi as well as in normal valve leaflets and papillary muscles. Especially if endocarditic vegetations are present its incoherent motion facilitates to recognize these small structures. The colorcode of this motion pattern demarcates the vegetation reliably from the surrounding tissue (Figure 1b). Within 15 seconds vegetations could be detected in 9 (82%) vs 2 (18%) patients employing only conventional imaging. Using conventional echocardiographic approaches detection of vegetations is frequently hindered by their small size and minor echo intensity (Figure 1a). In contrast, size and echo intensity do not affect the tissue Doppler signal. Normal papillary muscles and distal portions of the mitral and tricuspid valves were demonstrated to regularly meet the criterion of incoherent tissue motion in the control group. In part, this was also observed with respect to the aortic and pulmonary valves. In valvular tissue incoherent motion was caused by passive floating, whereas papillary muscles show an active inverse motion for short time intervals. Nevertheless, physiologic incoherent motion did not lead to any false differential diagnosis. The phase difference of coherent motion results from damped oscillation. This phenomenon was visualized by tissue Doppler M-mode in 5 thrombi of the left atrial appendage (LAA) (100%) and in 1 ventricular thrombus (50% of all clots). Concordant motion was shown in 3rd degree aortic plaques and postrheumatic and calcified vegetations. These structures were found to be completely embedded or closely attached, so that their passive motion corresponded to the motion of the surrounding regular tissue. Detection and assessment of anomalous structures are based on their motion patterns which can be synchronous or asynchronous in comparison with the surrounding tissue. Another goal of this investigation was to test if the sensitivity of TEE to spontaneous echo contrast can be improved using TDE. In 21 patients presenting with left atrial dilation (left atrial diameter > 44 mm) due to mitral stenosis (n = 8), mitral regurge (n = 5), arterial hypertension (n = 5) and multiple valvular disease (n = 3) fundamental multiplane TEE and transesophageal TDE were performed with standardized gain setting. The control group consisted of 20 randomized individuals with normal left

Aorta, Thoracic↗

PubMed1998

[Asynchrony of ventricular contraction and relaxation--pathophysiologically recognized phenomenon, now can be clinically assessed].

When regional myocardial dysfunction is present, the physiological pattern of ventricular filling and contraction is impaired. During acute coronary occlusion, characteristic changes are observed in the ischemic myocardial segment: the amplitude of the systolic wall thickening is reduced (hypokinesia), then virtually absent (akinesia) and finally replaced by a paradoxical outward motion (dyskinesia). The maximum amplitude is reached in early diastole ("post-ejection thickening"). Since hyperkinesis develops in the normal region, the ischemic and the normal region contract asynchronously. Experimentally left ventricular asynchrony can be detected by means of subendo- and subepicardially implanted ultrasonic crystals ("sonomicrometry") or by the analysis of the phase difference of the first Fourier harmonic of dysfunctional versus control myocardial wall motion. In the clinical setting, digitized cineventriculography, radionuclide angiography and digitized M-mode echocardiography were used to assess left ventricular asynchrony in patients with coronary artery disease and hypertrophic cardiomyopathy. However, these imaging modalities are time-consuming and require complicated off-line analysis. Tissue Doppler echocardiography (TDE) is a new ultrasound modality that is based on color Doppler principles and allows for quantification of myocardial wall motion velocity by detection of consecutive phase shifts of the ultrasound signal reflected from the myocardium. The Doppler signals are displayed as a color or pulsed Doppler image by rejecting low-amplitude echoes from the blood pool due to changes in thresholding and filtering algorithms. In addition, the ability to measure low velocity is improved in the TDE system so that the lowest measurable velocity is 0.2 cm/s, a velocity level associated with cardiac tissue motion (Table 1). Due to its high temporal and spatial resolution, TDE provides valuable information on regional myocardial wall motion during different intervals of the cardiac cycle. In healthy subjects, patients with coronary artery disease and patients with hypertrophic cardiomyopathy, tissue Doppler echocardiography was used to assess myocardial synchrony/asynchrony on a 2-fold temporal and spatial analysis. Peak myocardial velocities in different myocardial regions were detected during rapid ejection, isovolumic relaxation, rapid filling and atrial contraction (Figure 1). In the apical view, during the isovolumic relaxation time (IVRT) healthy subjects showed slow, synchronous outward motion of the septum and the lateral wall with homogeneous color-encoding (blue/green, Figure 2). Analysis of peak velocities revealed low, negative velocities in both the septum and the lateral wall (Figure 3). In patients with a significant luminal narrowing of the LAD myocardial asynchrony was detected during the isovolumic relaxation period: while the septum was moving inwards (red color-encoding with low, positive velocities), the lateral wall was moving outwards (blue/green encoding, low, negative velocities). A representative example of a patient with CAD is given in Figure 4. The M-mode analysis of the abnormally contracting interventricular septum reveals positive peak tissue velocities during the isovolumic relaxation period (Figure 5). In hypertrophic cardiomyopathy, TDE was able to detect an abnormal inward motion of the interventricular septum during IVRT and a delay in the onset of rapid filling (Figure 6). Thus, tissue Doppler echocardiography is a feasible method for the on-line detection of myocardial asynchrony. Sensitivity and specificity of the findings have to be explored in further, prospectively randomized trials.

Cardiomyopathy, Hypertrophic↗

PubMed1997

[Comparison of stress echocardiography and radionuclide ventriculography in the diagnosis of cardiomyopathy in patients receiving chemotherapy for malignant diseases].

BACKGROUND AND OBJECTIVE: Early evidence of drug-induced cardiomyopathy (CMP) is of great importance in haematological treatment, especially with anthracyclines. Stress echocardiography (SEC) has proved of value in determining left ventricular function at rest and under stress in patients with heart disease. The study was undertaken to assess the value of SEC in comparison with radionuclide ventriculography (RNV). PATIENTS AND METHODS: 63 unselected patients with malignant tumour (20 women, 43 men; mean age 49 +/- 15 years) underwent SEC and RNV. No chemotherapy had yet been started in 17 of them, 43 had received anthracyclines as main component of the chemotherapy (mean anthracycline dose 339 +/- 251 mg/m2). Left ventricular ejection fraction (LVEF) was measured by both SEC and RNV at rest and during standardized stress (recumbent ergometry). Both methods were applied and results measured independently by two examiners. RESULTS: The time interval between the two tests averaged 1 = 2 days. EC could be performed at rest in 62 of 63 and under stress in 59 of 63 patients (RNV: 63 of 63 and 54 of 63, respectively). Resting LVEF was 61 +/- 8% by SEC and 64 +/- 9% by RNV (P < 0.05). LVEF during stress, measured by SEC, was 71 +/- 11% and 73 +/- 10% by RNV (not significant). Mean LVEF increase between rest and stress was 9 +/- 10% by SEC and 9 +/- 8% by RNV (not significant). CONCLUSION: SEC is a satisfactory alternative to RNV in the assessment of ventricular function in patients receiving chemotherapy. It is less involved and more cost-effective than RNV, avoids radiation exposure and provides additional information on heart size and segmental contraction abnormalities.

Acute Disease↗

PubMed1997

[Detection of ventricular asynchrony using tissue Doppler echocardiography--a new method for assessing left ventricular wall motion].

UNLABELLED: The asynchrony of the heart in patients with coronary artery disease can be detected by digitized cine- and radionuclidventriculography. Both methods require time-consuming offline analysis. The aim of the current study was the assessment of the clinical value of the recently developed tissue Doppler echocardiography (TDE) to detect myocardial asynchrony. In the current study, 21 healthy subjects (age 49 +/- 14 y) and 22 patients with known coronary artery disease (20 with > 70% luminal narrowing of the LAD, 4 with a history of CABG, age 58 +/- 12 y) were included. In the apical 4-chamber-view, midseptal and midlateral LV segments were analyzed by 2-D and M-Mode-TDE. Evaluation was possible in 20 healthy subjects (95%) and 20 CAD patients (91%). During isovolumic relaxation time (IVRT) healthy subjects showed slow synchronous outward motion of the septum and the free wall with homogenous color coding (blue/green) and low negative tissue velocities followed by rapid symmetrical outward motion during rapid filling (RF) and atrial contraction (AC) phase (high negative velocities). During diatasis (DI) almost no wall motion could be detected. In 17 (85%) of 20 CAD patients, myocardial asynchrony during IVRT was detected; while the septum was moving inward (red coding with low positive velocities), the free wall was moving outward (blue green coding with low negative/velocities). After opening of the mitral valve, all CAD patients showed rapid, symmetrical outward motion of both the septum and the free wall with homogenous color coding and high negative tissue velocities. CONCLUSION: Tissue Doppler echocardiography detects ventricular asynchrony online. In patients with significant LAD stenosis, a pathological septal movement is observed during isovolumic relaxation time. Determinants of the etiology could be chronic hypoperfusion or ischemia ("hibernating myocardium").

Adult↗

PubMed1997

Reproducibility of stress echocardiography using intravenous injection of ultrasound contrast agent (BY 963).

UNLABELLED: Despite the widespread use of stress echocardiography, its reproducibility is still limited by high interobserver variability. Therefore, the purpose of the present study was to improve the reproducibility of a stress (exercise) echocardiography using a new transpulmonary ultrasound agent (BY 963). Stress echocardiography was performed in 12 healthy volunteers with suboptimal endocardial border delineation during exercise echocardiography. A special 45 degrees lateral tilted bike stress echocardiography table was used for exercise testing. Echocardiographic images were recorded on-line at rest and during exercise on a video tape and additionally digitized on-line on a stress echo computer. End-diastolic (EDVml), end-systolic (ESVml) volume and ejection fraction (EF%) were estimated in the 4-chamber view. The measurements were performed before and after injection of 2.5 ml and 5 ml BY963 at rest and in maximal exercise. A new contrast agent (BY 963) leads to a sufficient contrast effect for the left ventricular cavity after intravenous administration and permits a good delineation of left the endocardial border. The interobserver variability was determined using blinded investigation by two observers. The correlation of EDV and ESV determination at rest was r = 0.68/0.33, after 2.5 ml BY 963 r = 0.97/0.93 and after 5 ml BY 963 r = 0.90/0.93. The correlation for EDV and ESV during exercise was r = 0.52/0.33, after 2.5 ml BY 963 r = 0.88/0.80 and after 5 ml BY 963 r = 0.95/0.92. At rest mean EF without contrast was 61 +/- 6%/67 +/- 7% (r = 0. 130), after 2.5 ml BY 963 i.v. 69 +/- 8%/72 +/- 7% (r = 0.82) and after 5 ml BY 963 i.v. 73 +/- 8%/73 +/- 8% (r = 0.98%) respectively. In exercise, mean EF without contrast was 68 +/- 8%/70 +/- 6 (r = 0.013), after 2.5 ml BY 963 83 +/- 6%/81 +/- 5 and after 5 ml 83 +/- 4%/82 +/- 3 (r = 0.86). SUMMARY: The estimation of the end-systolic volume in exercise will be improved significantly and the estimated EF values will be higher compared to EF values obtained without contrast application. Transpulmonary contrast echocardiography for analysis of left ventricular volumes and ejection fraction can be routinely used in stress echocardiography. Intravenous administration of BY 963 improves the reproducibility of quantitative analysis of left ventricular function in healthy volunteers. Further studies in patients with cardiac diseases are required to corroborate this observation.

Adult↗

PubMed1997

Stress echocardiography: new techniques.

Stress echocardiography is frequently used to evaluate coronary artery disease, and also in quantitative assessment of right and left ventricular function or cardiac valve integrity in patients with cardiomyopathy or during chemotherapy. Various new ultrasound techniques in stress echocardiography are now playing a significant role in this important area of cardiological diagnostics. New methods of echocardiographic signal processing have been developed to provide more quantitative and reproducible information on cardiac function during stress. The most important are: (1) raw data analysis techniques for endocardial border detection (acoustic quantification, CK = colour kinesis), (2) tissue Doppler imaging for myocardial velocity analysis and (3) transpulmonary contrast agents (Albunex, Laevovist, BY 963) for improving endocardial border delineation and for future analysis of myocardial perfusion. Like all new techniques, they must first be subjected to comprehensive scientific assessment, and appropriate training should be given, taking into account physical and physiological limits. These limits will constantly be redefined as echocardiographic techniques continue to change presenting new challenges for the further development of ultrasound technology. In this review, the improved new techniques will be discussed in detail.

Animals↗

PubMed1996

[Intensive medical monitoring with transesophageal echocardiography in fulminant pulmonary embolism].

HISTORY AND FINDINGS: A 60-year-old man underwent a continence-preserving anterior rectal resection for a high rectal carcinoma. After mobilisation on the 5th postoperative day dyspnoea and cyanosis suddenly developed requiring emergency intubation and mechanical ventilation. INVESTIGATIONS: His heart rate was 160/min, blood pressure 80/50 mmHg, mean pulmonary artery pressure by indwelling catheter was 70 mmHg. The electrocardiogram had the classical signs of acute right-heart overload. Transoesophageal echocardiography (TOE) demonstrated marked right-heart and pulmonary artery dilatation. TREATMENT AND COURSE: Despite thrombolytic treatment (bolus of 50 mg r-TPA; one day later bolus of 1 million IU urokinase followed by 100,000 IU/h) a new thromboembolus was seen by TOE to straddle the pulmonary artery bifurcation. After the urokinase dosage had been raised to 200,000 IU/h TOE on the 6th day no longer showed the embolus and documented a reduction in right-heart dilatation associated with improved haemodynamics. CONCLUSION: TOE is an ideal method for the rapid diagnosis and for monitoring the response to treatment of fulminant pulmonary arterial embolism. As it can also diagnose thromboembolism without significant haemodynamic consequences it is possible to adjust fibrinolytic treatment accordingly.

Acute Disease↗

PubMed1994

[Spontaneous echo contrast in the left ventricle as an indicator for an increased risk of thromboembolism].

A 69-year-old man with coronary heart disease complained of pain in his right flank. He had dyspnoea, cough and fever up to 38.8 degrees C. In addition to various positive indicators of inflammatory disease he had a creatinine concentration of 1.8 mg/dl and an increased activity of lactate dehydrogenase (1655 U/l). The chest radiograph demonstrated pneumonia and computed tomography showed an infarct in the right kidney. The ECG indicated atrial fibrillation with an irregular ventricular rate and left bundle branch block. Echocardiography demonstrated dilatation of the left ventricle and a thrombus adherent to the wall. Transoesophageal echocardiography additionally recorded spontaneous type I echo-contrast, which disappeared after therapeutic heparinization. Cerebral infarctions were shown by computed tomography, undertaken because of neurological symptoms. There were also signs of silent myocardial ischaemia. As a coronary artery bypass operation was contraindicated, percutaneous transluminal balloon angioplasty was attempted but dissection occurred, causing irreversible cardiogenic shock of which the patient died.

Aged↗

PubMed1978

Collection of in vitro colony-forming units from dogs by repeated continuous flow leukaphereses.

The presence of in vitro colony-forming units (CFUc) was demonstrated in leukocyte suspensions collected by continuous flow leukaphereses performed serially in dogs. The CFUc yield of one leukapheresis was usually between 10(4) and 10(6). Higher yields were obtained in the 2nd to 5th leukaphereses than in the first one in the same dog. The number of CFUc collected during one leukapheresis was about four times the number of CFUc present in the circulating blood at the beginning of the leukapheresis. After a diminution during leukapheresis the circulating CFUc pool was restored in 2 or 3 days with an increase in the ratio of CFUc to mononuclear cells. These results indicate that CFUc entered the circulating pool during and after leukapheresis and that the population size regulation of canine-circulating CFUc is different from that of the bulk of the mononuclear leukoytes.

Animals↗

PubMed1978

Studies on the inhibitory effect of granulocytes on human granulocytopoiesis in agar cultures.

In the present study, the inhibitory effect of blood granulocytes on granulocytic colony formation from human white blood cells was tested. Attempts were made to clarify the effects of granulocytes by plating increasing numbers of polymorphonuclear cells (PMN) by using granulocytes which had been inactivated by freezing, by studying the effect of PMN removal and by observing the effect of dilution of granulocyte inhibitors to ineffective levels at different time intervals after the onset of culture. It will be shown that colony formation is inhibited by an excess of PMN and that the inhibitor is produced only by viable PMN. There is no inhibition during the early phase of the culture, thus suggesting that the CFU-C itself is not the target cell for the inhibition of colony formation in agar culture, but rather the more mature precursor cells of granulopoiesis.

Agar↗

PubMed1978

The role of phagocytic cells in human blood leukocyte suspensions for in vitro colony-forming cells.

The iron ingestion method was used to separate colony stimulating cells from in vitro colony forming cells (CFU-C) in human white blood cell (WBC) suspensions. The depletion of phagocytic cells (granulocytes and monocytes) from WBC eliminated spontaneous colony growth, without influencing the total number of CFU-C. Thus, phagocyte-free human WBC can be used as a target for measuring human colony stimulating activity (CSA). Such leukocytes can be cryopreserved, thus making possible the use of standardized target cell preparations for longitudinal studies. Hemolysate added to phagocyte-free blood leukocytes did not induce colony formation but could enhance it in the presence of a suitable CSA. Spontaneous colony formation of unseparated WBC was significantly reduced by selective destruction of granulocytes by freezing in 10% DMSO, thus indicating that both granulocytes and monocytes are involved in the production of endogenous CSA in WBC suspensions.

Cell Division↗

PubMed1977

Cryopreservation of blood mononuclear leukocytes and stem cells suspended in a large fluid volume. A preclinical model for a blood stem cell bank.

It was the purpose of this study to establish and evaluate a freezing-and-thawing method for preservation of hemopoietic stem cells from the peripheral blood. Blood leukocytes collected by means of an IBM Blood-Cell-Separator were frozen in plastic bags using 10% DMSO and controlled cooling rates. Thawing was performed rapidly, and DMSO was diluted and removed prior to the in-vitro and in-vivo assays. The mean recovery of mononuclear cells collected from 82 leukaphereses was 86%. To assess the recovery of cryopreserved hemopoietic stem cells, the soft agar culture method adapted for the dog was used. There was no significant difference in the CFUc recovery per 1 X 10(6) mononuclear cells or in per leukapheresis after different cryopreservation times (1--6 and 7--27 months). To evaluate the hemopoietic repopulation capability of cryopreserved blood stem cells, leukapheresis-derived leukocytes were transfused into 1200 R whole body x-irradiated dogs. The hemopoietic repopulation pattern at day 10 after transfusion of comparable numbers of fresh or frozen leukocytes was not significantly different, as measured in bone marrow smears and sections and by granulocyte concentration in the peripheral blood.

Animals↗

PubMed1977

Studies on the regeneration of the CFU-C population in blood and bone marrow of lethally irradiated dogs after autologous transfusion of cryopreserved mononuclear blood cells.

In a group of 8 lethally irradiated (1200 R) dogs, that were transfused autologously with cryopreserved mononuclear cells (MNC) derived from the peripheral blood by leucapheresis the concentration of colony-forming units in agar (CFU-C) in bone marrow and peripheral blood was estimated at regular intervals after irradiation and transfusion of MNC. The numbers of MNC transfused per kg body weight ranged from 0.32 x 10(9) to 1.63 x 10(9) with an incidence of CFU-C between 0.02 x 10(5) and 1.38 x 10(5). In 6 dogs the CFU-C levels in the bone marrow reached the normal pre-irradiation values between days 15 and 20. But in 2 dogs that had received the lowest CFU-C numbers the regeneration of the bone marrow CFU-C was markedly delayed. In general the time course of the bone marrow repopulation by CFU-C for single dogs was reflected by a corresponding regeneration pattern of the blood CFU-C. The time course of the curves for the blood CFU-C levels on the other hand was of the same kind as for the granulocyte values in the peripheral blood, thuations were seen in the blood CFU-C levels of single dogs before irradiation and after mononuclear leucocyte transfusion. Despite of such limitations the blood CFU-C content appeared to be a useful indicator of haematopoietic regeneration of the bone marrow.

Animals↗

PubMed1976

Colony formation by canine hemopoietic cells in vitro. Inhibition by polymorphonuclear leukocytes.

In soft agar cultures of canine blood leukocytes, an inhibition of colony formation was observed relative to the size of the inoculum. Analysis of the cellular composition of the inoculum suggested that this inhibition was associated with the number of polymorphonuclear leukocytes present. Removal of phagocytic cells by the iron ingestion method or selective destruction of granulocytes by freezing in the presence of dimethyl sulfoxide eliminated the inhibitory action on colony formation. In mixed cultures of canine bone marrow and antologous blood leukocytes, a similar inhibition of colony formation was observed. The results presented indicate that polymorphonuclear leukocytes, if present in a concentration exceeding 2.5X10(6)/ml of inoculum, inhibit in vitro granulocytic/monocytic colony formation.

Animals↗

PubMed1976

Regeneration of blood-forming organs after autologous leukocyte transfusion in lethally irradiated dogs. II. Distribution and cellularity of the marrow in irradiated and transfused animals.

Dogs were given transfusions of cryopreserved autologous mononuclear blood leukocytes after 1200 roentgens (R) (midline dose) whole-body x-irradiation. Bone marrow repopulation was studied by means of histomorphological methods at days 9 and 10 after transfusion of an average of 3 X 10(9), 7 X 10(9), 13 X 10(9), and 31 X 10(9) cells. The return of marrow cellularity to normal values was related to the number of cells transfused. With low cell doses (3 X 10(9) and 7 X 10(9)), the marrow regeneration at 10 days was focal. There were groups of cells (colonies) showing either erythropoiesis, myelopoiesis, or megakaryocytopoiesis in the osteal niches of the trabecular bones. Frequently such niches were seen showing complete cellular recovery next to niches with complete aplasia. With higher cell doses, all niches showed hemopoietic regeneration, and the cellularity approached normal values. No hemopoietic regeneration was observed in those skeletal parts that do not show hemopoiesis, even under normal circumstances.

Animals↗