Beyond the marrow: insights from comprehensive next-generation sequencing of extramedullary multiple myeloma tumors

Extramedullary multiple myeloma (EMM) is an aggressive form of multiple myeloma (MM). This study represents the most comprehensive next-generation sequencing analysis of EMM tumors (N = 14) to date, uncovering key molecular features and describing the tumor microenvironment. We observed the co-occurrence of 1q21 gain/amplification and MAPK pathway mutations in 79% of EMM samples, suggesting that these are crucial mutational events in EMM development. We also demonstrated that patients with mutated KRAS and 1q21 gain/amplification at the time of diagnosis have a significantly higher risk of EMM development (HR = 2.4, p = 0.011) using data from a large CoMMpass dataset. We identified downregulation of CXCR4 and enhanced cell proliferation, along with reduced expression of therapeutic targets (CD38, SLAMF7, GPRC5D, FCRH5), potentially explaining diminished efficacy of immunotherapy. Conversely, we identified significantly upregulated EZH2 and CD70 as potential future therapeutic options. For the first time, we report on the tumor microenvironment of EMM, revealing CD8+ T cells and NK cells as predominant immune effector cells using single-cell sequencing. Finally, this is the first longitudinal study in EMM revealing the molecular changes from the time of diagnosis to EMM relapse.

Early Activation of Hemostasis during Cardiopulmonary Bypass: Evidence for Thrombin Mediated Hyperfibrinolysis

In 14 consecutive patients undergoing cardiopulmonary bypass for coronary bypass surgery the time course of coagulation and fibrinolysis markers were measured, e.g. plasma levels of thrombin-antithrombin III (TAT) complexes, cross-linked fibrin degradation products (X1FDP) and plasmin-α2-antiplasmin complexes (PAP). TAT levels exceeded the 90% baseline percentile already during CPB (after opening of aortic clamp) in 10 patients, whereas PAP and X1FDP exceeded their 90% percentile in only one patient at this time. Concerning fibrinolysis markers PAP and X1FDP the majority of patients showed elevations higher than their 90% baseline percentile only 1 h postoperation. Correlation analysis revealed significant dependencies between TAT levels during and at the end of CPB and PAP levels 1 h postoperation (R = 0.55 and R = 0.56 respectively). Furthermore, 1 h postoperation X1FDP levels were significantly correlated with both TAT and PAP. Peak X1FDP levels at the same time correlated with blood loss via thoracic drains (R = 0.56). Thus, we suggest that hyperfibrinolysis in patients undergoing CPB is at least partly due to hypercoagulation. Clinically, this may implicate that intensified anticoagulation could prevent hyperfibrinolysis and reduce postoperative blood loss.

Effects of functional endoscopic sinus surgery on the acoustics of the sinonasal tract

BACKGROUND

Nasal and paranasal cavities are supposed to contribute substantially to the vocal tract resonator properties. However, their acoustical effects as well as the effects of sinus surgery on the voice remain unclear. In this work we investigate resonance phenomena of paranasal sinuses prior to and after various rhinosurgical procedures in cadaveric human sinonasal tracts and corresponding 3D casts.

METHODOLOGY

Nasal and paranasal cavities of formalin-preserved cadavers and corresponding 3D replicas were excited by sine-tone sweeps from an earphone placed in the epipharynx. The response was picked up by a microphone at the nostrils. Different FESS procedures were performed and the acoustical responses following excitation were recorded. The measured acoustical changes in the obtained transfer functions were then evaluated.

RESULTS

Marked low frequency dips were detected in the transfer functions when sinus cavities were included in the nasal resonator system. These dips showed a significant correlation with sinus volumes. Following FESS procedures they moved upwards in frequency depending on the extent of the surgical intervention.

CONCLUSIONS

The transfer functions obtained in cadaveric situs and 3D replicas showed dips at the resonance frequencies of the paranasal cavities. Marked acoustic effects in terms of increase in dip frequency following FESS procedures were reproducibly documented.

Resonator properties of paranasal sinuses: preliminary results of an anatomical study

BACKGROUND

The contribution of the nasal and paranasal cavities to vocal tract resonator properties is unclear as are voice effects of sinus surgery. Here we investigate resonance phenomena of paranasal sinuses with and without selective occlusion of the middle meatus and maxillary ostium in a cadaver.

METHODOLOGY

Nasal and paranasal cavities of a Thiel-embalmed cadaver were excited by sine-tone sweeps from an earphone in the epipharynx. The response was picked up by a microphone at the nostrils. Different conditions with blocked and unblocked middle meatus were tested. Additionally, infundibulotomy was performed allowing direct access to and selective occlusion of the maxillary ostium.

RESULTS

Responses showed high reproducibility. Minor effects appeared after removal of meatal occlusion. A marked low frequency dip was detected after removal of occlusion of maxillary ostium following infundibulotomy.

CONCLUSION

Reproducible frequency responses of nasal tract can be derived from cadaver measurements. Marked acoustic effects of the maxillary sinus appeared only after direct exposure of the maxillary ostium following infundibulotomy.

Patient comfort following FESS and Nasopore® packing, a double blind, prospective, randomized trial

Background: The use of nasal packing after functional endoscopic sinus surgery (FESS) is often associated with pain and a feeling of pressure for patients. The aim of the present work was to investigate a modern wound dressing made of polyurethane (Nasopore®) that makes removal of the nasal packing unnecessary and is focussed on patient comfort. Methodology: Following bilateral FESS, after randomisation, one side was packed with Nasopore® while the other side was without packing as a control. The following parameters from 47 patients were determined daily in two centres from post-operative day 1 for the duration of the inpatient stay in a double-blinded setting: side-specific post-operative bleeding, nasal breathing and feeling of pressure as well as the general parameters sleep disturbance, headaches and general well-being. Which side patients considered subjectively the better was also recorded. Results: No significant differences were determined between the two sides in terms of the rates of post-operative bleeding and nasal breathing. The feeling of pressure was slightly less on the side packed with Nasopore® on post-operative days 2 and 3. No trend could be observed regarding which side patients described as being subjectively better. Conclusion: There were only slight differences in patient comfort between the Nasopore® side and the control. Because the feeling of pressure in the midface was significantly less and there were no complications, this suggests there is greater patient comfort when using Nasopore® compared to using no nasal packing.

Endoscopic sinus surgery training courses: benefit and problems - a multicentre evaluation to systematically improve surgical training

BACKGROUND

The aim of this multicentre study was to systematically analyse the strengths and weaknesses in the surgical training for endoscopic sinus surgery (ESS) and identify measures that may improve training.

METHODOLOGY

Using a structured questionnaire, 133 participants of ESS courses in seven centres in Germany, Switzerland and Australia were asked about their experiences during their dissection courses and how they perceived their course could be improved.

RESULTS

Gaining confidence in handling of instruments and endoscopes was only a problem for participants with little experience in ESS. The majority of the participants, independent from their level of training, considered infundibulotomy and anterior ethmoidectomy as the easiest dissection steps, whilst surgery of the frontal sinus posed a considerable challenge for many surgeons even those with a higher level of training. Participants with and without ESS experience thought that emphasis on anatomy was the most important improvement that could be made during their surgical training. Virtually all participants stated that the course improved their anatomical knowledge, their surgical skills and their confidence when performing ESS.

CONCLUSIONS

ESS dissection courses are considered beneficial by surgical trainees. Participants felt that more emphasis on sinus anatomy in conjunction with private study is essential to maximize their skills in surgical dissection. For beginners with ESS, an infundibulotomy and anterior ethmoidectomy were thought to be the best initial procedures to help develop endoscopic surgical skills.

Endoscopic measurements of free-flap perfusion in the head and neck region using red-excited Indocyanine Green: preliminary results

BACKGROUND

Free-tissue transfer has become a standard procedure for reconstructive surgery in the head and neck area. Flap failures are relatively rare (<or=5%), and a high percentage can be salvaged if detected early. Indocyanine Green (ICG) angiography might be able to improve the detection of flap malperfusion at an early stage.

METHODS

So far, 11 patients with free-flap reconstructions of the upper aerodigestive tract (UADT) have participated in this study. Each participant underwent three endoscopic ICG angiographies (24h intra-operatively and 72h postoperatively). The data obtained were evaluated online as well as offline on a personal computer (PC), and the results compared to the clinical outcome.

RESULTS

There were no partial or complete flap losses. One flap was successfully salvaged following initial arterial kinking with impeded perfusion. The ICG fluorescence angiography was tolerated well in all patients. The free flaps showed a delayed yet equal ICG fluorescence as compared to the surrounding tissue. The timing and slope of fluorescence build-up were dependent on circulatory factors. The relative fluorescence maxima of flap versus surrounding were 33% in the initially failing flap and >or=64% for all other examinations.

CONCLUSIONS

It was possible to prove the feasibility of endoscopic ICG fluorescence angiography in patients undergoing free-flap transfer to the UADT. The method provides instant information about the perfusion state of the tissue and is easily performed without greater patient discomfort or risk of side effects. Due to the endoscopic approach, the method seems highly promising for this indication and merits further evaluation.

Phonon confinement in SiC nanocrystals: comparison of the size determination using transmission electron microscopy and Raman spectroscopy

Silicon carbide fibers of different generation/processing routes (NLM-Nicalon and Tyranno SA3) were thermally treated to trigger the growth of nanocrystals, which were analyzed using Raman spectroscopy and transmission electron microscopy (TEM). The nanocrystals were also aged in molten sodium nitrate to investigate their reactivity. The spatial correlation model has been used to model the Raman spectra and extract accurate and statistical information on the nanocrystallites' structure and dimension. For the NLM fibers, an average size of 2.5 to 7.0 nm was calculated, which was in good agreement with TEM observations. For the Tyranno SA3 fiber, despite the heavily faulted stacking sequence, the Raman peaks remained sharp, indicating that the crystallite dimension calculated from the Raman spectra is only dependent on the actual size of the nanocrystals and is not affected by the sequence of the stacking faults.

Thoracic aortic aneurysms: treatment with endovascular self-expandable stent grafts

BACKGROUND

This study was performed to evaluate the safety and feasibility of endovascular stent graft placement in the treatment of descending thoracic aortic aneurysms.

METHODS

Between November 1996 and February 1999, endovascular stent graft repair was used in 21 patients. There were 5 women and 16 men with a mean age of 67 years (range, 41 to 87 years). An atherosclerotic aneurysm with a diameter of more than 6 cm was the indication for intervention in 19 patients (90.5%). In 2 patients (9.5%), a localized aortic dissection with a diameter of more than 6 cm was treated. In 71.4% (15 of 21) of patients, multiple stents were necessary for aneurysm exclusion. To allow safe deployment of the stent graft, preliminary subclavian-carotid artery transposition was performed in 9 patients (42.9%). Vascular access was achieved through a small incision in the abdominal aorta (n = 6), an iliac artery (n = 8), or a femoral artery (n = 7). Talent and Prograft stent grafts were used.

RESULTS

Successful deployment of the endovascular stent grafts was achieved in all patients. Two patients died postoperatively (mortality rate, 9.5%), 1 of aneurysmal rupture and the other of impaired perfusion of the celiac axis. Repeat stenting was done in 3 patients because of intraoperative leakage.

CONCLUSIONS

Endovascular stent graft repair is a promising and less invasive alternative to exclude the aneurysm from blood flow. This technique allows treatment of patients who are unsuitable for conventional surgical procedures. An exact definition of inclusion criteria and technical development of stent grafts should contribute to further improvements in clinical results.

Impact of retrograde cerebral perfusion on aortic arch aneurysm repair

OBJECTIVE

Protection of the brain is a primary concern in aortic arch surgery. Retrograde cerebral perfusion is a relatively new technique used for cerebral protection during profound hypothermic circulatory arrest. This study was designed to compare, retrospectively, the outcome of 109 patients undergoing aortic arch operation with and without the use of retrograde cerebral perfusion.

METHODS

Fifty-five patients had profound hypothermic circulatory arrest alone, and 54 patients had supplemental cerebral protection with retrograde cerebral perfusion. Mean age was 61 +/- 13 years and 58 +/- 14 years, respectively (mean +/- standard deviation). Twenty-two preoperative and intraoperative characteristics, including age, sex, acuity, presence of aortic dissection, and aneurysm rupture, were similar in the 2 groups (P >.05).

RESULTS

Mean circulatory arrest times (in minutes) were 30 +/- 19 in the group without retrograde cerebral perfusion and 33 +/- 19 in the group with retrograde cerebral perfusion, respectively. chi(2) Analysis revealed that patients operated on with the use of retrograde cerebral perfusion had significantly lower hospital mortality (15% vs 31%; P =.04) and in-hospital permanent neurologic complications (9% vs 27%; P =.01). Retrograde cerebral perfusion failed to reduce the prevalence of temporary neurologic dysfunction (17% vs 18%; P =.9). Stepwise multiple logistic regression revealed that extracorporeal circulation time, age, and lack of retrograde cerebral perfusion were statistically significant independent risk factors for hospital mortality. The same analysis revealed that lack of retrograde cerebral perfusion was the only significant independent risk factor for permanent neurologic dysfunction.

CONCLUSION

Retrograde cerebral perfusion decreased the prevalence of permanent neurologic complications and the hospital mortality in patients undergoing aortic arch operations.

Memantine for prevention of spinal cord injury in a rabbit model

BACKGROUND

This study was conducted to investigate the effect of memantine, a noncompetitive N-methyl-d-aspartate receptor antagonist, on the neurologic outcome of spinal cord ischemia after aortic occlusion.

MATERIALS AND METHODS

New Zealand White rabbits were anesthetized and spinal cord ischemia was induced for 40 minutes by infrarenal aortic occlusion. Animals were randomly allocated to 3 groups. Group 1 (n = 8, control) received no pharmacologic intervention, group 2 (n = 8) received intra-aortic memantine infusion (20 mg/kg) after aortic crossclamping, and group 3 (n = 8) was treated with systemic memantine infusion (20 mg/kg) 45 minutes before aortic occlusion. Neurologic status was scored by the Tarlov system (in which 4 is normal and 0 is paraplegia) at 12, 24, 36, and 48 hours after the operation. Lumbar spinal root stimulation potentials and motor evoked potentials from lower limb muscles were monitored before, during, and after the operation. After the animals were killed, the spinal cords were studied histopathologically.

RESULTS

All potentials disappeared shortly after aortic crossclamping. They returned earlier in both memantine-treated groups than in the placebo group. Histologic examination of spinal cords revealed a few abnormal motor neurons in memantine-treated rabbits but found extensive injury in the control group. At 12 hours the median Tarlov scores were 0 in the control group (group 1), 2 in the intra-aortic memantine group (group 2, P =.001 versus control), and 3 in the systemic group (group 3, P =.0002 versus control). At 24 hours median Tarlov scores were 0, 2.5 (P =.0002), and 4 (P =. 0002), respectively. Finally, at both 36 and 48 hours median Tarlov scores were 0, 3 (P =.0006), and 4 (P =.0002), respectively.

CONCLUSION

Memantine significantly reduced neurologic injury related to spinal cord ischemia and reperfusion after aortic occlusion.

Perioperative risk factors for mortality in patients with acute type A aortic dissection

BACKGROUND

Patients with acute type A aortic dissection are associated with a high mortality rate and postoperative complications. This study was designed to explore perioperative risk factors for death in patients with acute type A aortic dissection.

METHODS AND RESULTS

One hundred nine consecutive surgical patients with acute type A aortic dissection were included in the present study. Thirty-five perioperative risk factors were used in the statistical analysis for mortality prediction. The 30-day mortality rate for all patients was 30% (33 of 109). Univariate analysis revealed 5 preoperative and intraoperative risk factors that were found to be statistically significant predictors for death: older age, renal failure, preoperative hemodynamic instability, preoperative cardiopulmonary resuscitation, and lack of retrograde cerebral perfusion (P < 0.05). Rupture of aneurysm, hypothermic circulatory arrest time, and operation date were not found to be risk factors for death. Stepwise multiple logistic regression confirmed that older age and lack of retrograde cerebral perfusion were statistically significant independent risk factors for death (P < 0.05). Four postoperative complications were found to be statistically significant prognostic indicators for death: liver failure, stroke, sepsis, and reoperation after the initial surgery (P < 0.05).

CONCLUSIONS

Perioperative risk factors for death after the operation for acute type A aortic dissection were identified. This will allow physicians and surgeons to better assess the patient's risk, which will lead to better outcome.

Endovascular stent graft repair for aneurysms on the descending thoracic aorta

BACKGROUND

The traditional treatment of aneurysms of the descending thoracic aorta includes posterolateral thoracotomy and aortic replacement with a prosthetic graft. In this study, we report our experiences and results in endovascular stent graft placement as an alternative to surgical repair.

METHODS

Between January 1989 and July 1997, a total of 68 patients (24 women) underwent replacement of the thoracic aorta. Mean age at operation was 51 years. Fifty-eight patients underwent conventional surgical treatment. All of these patients were suitable candidates for endovascular stenting; however, no stent graft material was available at the time of operation. Ten patients (1 chronic dissection, 9 atherosclerotic aneurysm) received in the past 8 months the first commercially manufactured endovascular stent graft. The mean diameter of the aneurysms in this group was 7 cm (range, 6 to 8 cm). Two stent patients were operated on using only spinal cord analgesia. All stent grafts were custom designed for each of the 10 patients.

RESULTS

The 30-day mortality in the conventional group was 31% versus 10% in the stent group. Mean length of intervention was 320 minutes in the conventional group versus 150 minutes in the endovascular group. Spinal cord injury occurred in 5 patients (12%) in the surgical group, whereas none of the stented patients developed any neurologic sequelae. Mean intensive care unit stay was 13 days, followed by a mean of 10 days on a ward in the first group compared to 4 days in the intensive care unit and 6 days on the ward in the stent group. One stent was required in 2 patients, two stents were required in 3 patients, and four stents were deployed in 5 patients of our series. Five patients required transposition of the left subclavian artery to achieve a sufficient neck for the proximal placement of the stent. There was complete thrombosis of the thoracic aortic aneurysm surrounding the stent graft in 8 patients (80%). Two patients required restenting as a result of leakage (20%). Stent graft placing was performed through the femoral artery in 8 patients, whereas access was only achieved through the abdominal aorta in 2 patients.

CONCLUSIONS

These preliminary results demonstrate that endovascular stent graft replacement might be a promising, cheaper, and safe alternative method in selected patients with descending thoracic aneurysms.

[Selected aspects for quality assurance in family practice]

All general practitioners of Dresden, the capital of Saxonia, were interviewed about problems of the quality assurance twice, 1995 and a year after. In 1995, the response rate was 60.7%, in 1996 83.8% of the first participants. The majority of the doctors are interested in the quality assurance of the medical care by family doctors including their own work. In their view, the different possibilities of the quality assurance and the various kinds of further medical training are of different importance. This estimation can depend on the age and sex of the physicians and on the kind of practice-organization.

[Spatial and temporal accessibility of primary health care by the patient--a survey in Dresden/Saxony]

The structural changes in outpatient medical care in eastern Germany took place by far-reaching winding up of the outpatient departments. At the same time, many doctors from these institutions set up a practice. These changes also concerned the medical care by family doctors. It is assumed that as a result of these partly extensive changes there are also changes in the accessibility of the family doctor by outpatients. We will describe in this paper the level attained in Dresden, capital of Saxony in 1995 and 1996, from the point of view of the inhabitants. Existing problems are shown. In this connection, random samples of inhabitants of Dresden were interviewed by postal survey with questions on this subject in 1995 and 1996.

Operations on the thoracic aorta and hypothermic circulatory arrest: is aprotinin safe?

INTRODUCTION

The safety of aprotinin, especially when used with profound hypothermic circulatory arrest, is still a matter of intense debate despite its presumed salutary effects on blood loss. Many investigators have reported toxic renal effects of high-dose aprotinin in such patients, but no prospective, randomized study has been conducted. To assess the potential detrimental effect of aprotinin on renal function and its putative reduction of blood loss, 50 patients undergoing thoracic aortic operations with the use of profound hypothermic circulatory arrest were randomly assigned to receive either low-dose aprotinin (1 x 10(6) kallikrein activation units) or placebo.

METHODS

The specific renal tubular markers beta-2-microglobulin and beta-N-acetyl-D-glucosaminidase, as well as serum creatinine and blood urea nitrogen, creatinine clearance, sodium excretion, and potassium excretion, were measured to evaluate renal function preoperatively, immediately after the procedure, and 24 hours and 48 hours later.

RESULTS

No statistically significant difference was found in any measured renal parameter between the two groups (analysis of variance). Renal dysfunction, defined as an elevation of serum creatinine early postoperatively (> or = 1.5 times the preoperative value), occurred in two patients who received aprotinin and in one patient in the control group. Temporary dialysis (hemodialysis or continuous venovenous hemofiltration) was needed in two patients in the aprotinin group versus one in the control group. Furthermore, patients treated with aprotinin had significantly less total postoperative blood loss (718 +/- 340 ml vs 920 +/- 387 ml, p = 0.04). The aprotinin recipients also had a significantly lower transfusion requirement (p < 0.05).

CONCLUSION

This controlled trial of low-dose aprotinin in patients undergoing thoracic aortic operations using profound hypothermic circulatory arrest demonstrated no detectable deleterious effects on renal function; moreover, the use of aprotinin was associated with significantly lower need for transfusion.

Surgical treatment of aortic arch aneurysms in profound hypothermia and circulatory arrest

BACKGROUND

This study was undertaken to define the factors that influence mortality rate and neurologic outcome after repair of the aortic arch and various portions of the thoracic aorta in patients with profound hypothermia and circulatory arrest.

METHODS

Between November 1986 and January 1996, 105 patients were treated surgically for aortic disease involving the transverse aortic arch. Profound hypothermic circulatory arrest and selective brachiocephalic perfusion was used in all patients. In 19 patients retrograde cerebral perfusion was instituted during the period of circulatory arrest. Independent predictors for 30-day mortality and permanent neurologic deficits were evaluated by multiple logistic regression.

RESULTS

Thirty-day mortality for the entire group was 19% (20/105); 21.2% for urgent versus 15.4% for elective cases, respectively. Statistical analysis showed that age is the most important factor that significantly influences mortality rate (p < 0.0145) and neurologic outcome (p < 0.006). Variables such as circulatory arrest time (p < 0.24), previous cardiac or aortic operations (p < 0.19), and sex (p < 0.55) failed to show any influence on mortality rate. Permanent neurologic deficits were diagnosed in 12.9% (11/85) of the patients.

CONCLUSIONS

The incidence of permanent neurologic dysfunction as well as the mortality rate are predominantly related to the age of the patient. In this patient group, statistical analysis failed to show a direct correlation between duration of circulatory interruption and neurologic outcome.

The use of profound hypothermia and circulatory arrest in operations on the thoracic aorta

OBJECTIVE

This retrospective study reviews the contemporary surgical outcome of our patients undergoing operations on thoracic aneurysms in deep hypothermic circulatory arrest.

METHODS

Between January 1989 and February 1995, 279 patients were operated on in our institution on various portions of the aorta. In 143 patients (97 male, 46 female), deep hypothermia and circulatory arrest were used as the standard operative technique. Patients age ranged from 16 to 83 years (mean 55). Final indication for operation was dissection Type A in 80 patients (61 acute, 19 chronic), dissection Type B in 21 patients (17 acute, 4 chronic) and atherosclerotic aneurysms in 42 patients (11 acute, 31 chronic). 16 patients were operated under preoperative unstable hemodynamic conditions, 6 patients had been resuscitated preoperatively. Surgical technique included cardiopulmonary bypass with femoral artery cannulation. For added cerebral protection all patients received Cortisone and barbiturates right before circulatory arrest (confirmed by 0-EEG). The segment of the aorta containing the area with the aneurysm, was resected and replaced with a tubular albumin coated graft.

RESULTS

The 30-day mortality was 31.15% (19/61) in the acute and 23.52% (4/19) in the chronic type A dissection group, 35.29% (6/17) in the acute and 25% (1/4) in the chronic type B group, 36.3% (4/11) in the acute and 22.58% (7/31) in the chronic atherosclerotic group. Causes of postoperative death in order of frequency were: multiorgan failure (n = 15), myocardial failure (n = 13), bleeding (n = 4), sepsis (n = 4), myocardial infarction (n = 3) and stroke (n = 2).

CONCLUSION

Despite rather high mortality rates in the acute aneurysm groups, the technique of profound hypothermic circulatory arrest represents a relatively safe method for operations on the thoracic aorta.

Operative management of aortic arch aneurysm using profound hypothermia and circulatory arrest

Since the first successful replacement of the aortic arch with perfusion of the head, various methods have been employed to preserve cerebral function during aneurysm operations. Although deep hypothermia was used for surgery of the aortic arch, as early as 1963, the introduction of prolonged circulatory arrest has simplified replacements of the aortic arch. Between October 1990 and September 1993, 69 patients underwent aortic arch replacement for aneurysmal disease at the Dept. of Cardio-Thoracic Surg., University of Vienna. 52 patients had an acute dissection Type A, 17 patients were operated on electively. The patients age (48 male, 21 female) ranged between 16 and 81 years. Primary diagnosis was hypertension (n=44), marfan (n=14), unknown (n=10) and trauma (n=1). Total cardiopulmonary bypass was established via femoral artery cannulation. All patients received Cortison and Thiopental for added cerebral protection. Deep hypothermia (12 degrees C), confirmed by 0-EEG, and circulatory arrest were induced in all patients. The aneurysm was opened longitudinally and a full thickness single patch or "island" of aortic wall, containing the origins of the three arch vessels, was constructed and anastomosed in a continuous fashion to an albumin coated graft. 68 patients survived the operation (intraoperative mortality 1%). The 30-day mortality was 23% (n=16). Twelve patients died of multiorgan failure, two patients of a stroke and two due to myocardial infarction. The mean cerebral circulatory arrest time was 32 minutes (range 11-61 min.). Our experience with aortic arch replacements using profound hypothermia and circulatory arrest supports our contention, that it is the method of choice in this very difficult surgical field.

[Surgery of thoracic and thoraco-abdominal aneurysms using deep hypothermia and cardiovascular arrest with continuous administration of blood cardioplegia]

Between January 1991 and February 1993, 14 patients (3 female, 11 male) aged between 21 and 79 years (mean 50 years) underwent reconstruction of the thoracic (n = 7) and thoracoabdominal aorta (n = 7). Four patients had previously undergone operation of the ascending aorta, in 3 patients coronary artery by pass grafting was performed before. All patients were operated using cardiopulmonary bypass with continuous blood cardioplegia, hypothermic circulatory arrest (11 degrees C nasopharyngeal temperature, 0-EEG) and posterolateral exposure. All patent lower intercostal and lumbar arteries (Th3-L5) were reimplanted. The 30-day mortality after repair of the thoracic aorta was 0, after replacement of the thoracoabdominal aorta 28.5% (n = 2). One patient died 70 days after replacement of the thoracic aorta as a consequence of a perioperative stroke. None of the surviving 11 patients developed a permanent neurologic deficit, renal or cardiac dysfunction. The average intensive care stay was 6 days for patients after replacement of the thoracic and 18 days for patients after replacement of the thoracoabdominal aorta. Our results indicate the method of elective hypothermia and circulatory arrest effective in spinal cord protection. The increase in the tolerable duration of spinal cord ischemia supports the reimplantation of all intercostal and lumbar vessels.

Aortic valve resuspension in ascending aortic aneurysm repair with aortic insufficiency

BACKGROUND

The known complications of prosthetic valve replacement in patients with an ascending aortic aneurysm and secondary aortic regurgitation who frequently have a morphologically normal aortic valve have prompted interest in valve-sparing aneurysm repair procedures. The aim of this study was to define the echocardiographic criteria for identifying suitable candidates for ascending aortic aneurysm repair that spares the aortic valve. We also examined the perioperative and intermediate-term results of this innovative procedure.

METHODS

Fifteen patients underwent ascending aortic replacement with resuspension of the native valve within a vascular prosthesis and reimplantation of the coronary ostia. Echocardiography was performed preoperatively and intraoperatively, before discharge, and during follow-up. Thirteen patients had nondissecting aneurysms, and 2 patients had a Standford type A aortic dissection. The mean age of the patients was 48 +/- 18 years. Only patients with morphologically normal aortic leaflets and leaflets of similar size were selected.

RESULTS

There was one death perioperatively, and this was due to sepsis. The procedure failed in 1 patient, and a valved conduit was implanted during the same operation. In the 13 others the aortic annulus diameter was significantly reduced from 27.1 +/- 2.2 mm preoperatively to 22.2 +/- 1.9 mm postoperatively (p < 0.05). The severity of aortic insufficiency decreased from 2.9 +/- 0.7 to 0.6 +/- 0.4 (p < 0.05). The peak aortic gradient increased from 11.5 +/- 6.5 to 20.3 +/- 16 mm Hg. A slight increase in the aortic annulus diameter to 24.3 +/- 1.0 mm and normalization of the peak aortic gradient to 9.8 +/- 7.8 mm Hg were noted at follow-up. There was no significant increase in aortic insufficiency.

CONCLUSIONS

In selected patients undergoing ascending aortic aneurysm repair who have normal aortic leaflets but secondary aortic regurgitation, the native valve can be spared through this novel operation. The aortic annulus size is reduced significantly, thereby effectively eliminating hemodynamically significant aortic regurgitation. The intermediate-term results are promising, but the long-term durability of this type of repair needs to be determined.

[Results of valve-sparing correction of aortic valve insufficiency]

The risk of valve-related complications and the necessity of anticoagulation in patients with prosthetic valves, has led to new operative techniques in the correction of severe aortic insufficiency. In the last 2 years, 35 patients (mean age 41.3 years, range 10-80 years) with aortic insufficiency underwent reconstructive valves surgery. Eighteen patients had a commissuroplasty with or without triangular resection. In 5 patients with perforation, the valves could be reconstructed with a pericardial patch. In 12 patients with insufficiency due to aortic aneurysm, the valves were resuspended within the aortic prosthesis. In 2 patients the aortic valves were replaced intraoperatively because of unsatisfactory results. The perioperative mortality was 5.7%. The echocardiographic degree of aortic insufficiency decreased from 3.3 +/- 0.5 preoperatively to 0.45 +/- 0.53 postoperatively. Two patients were reoperated within the first week. Five of 23 patients at 1-year follow-up have mild to moderate aortic insufficiency. Mean ventricular dimensions and function at discharge and after 1-year follow-up are normal. With the new operative techniques described recently, valve-sparing corrections of aortic insufficiency are possible in an increasing number of patients, and autologous valve tissue can be saved. With more refinement of surgical technique, early postoperative results will further improve.

Transoesophageal echocardiographic follow-up of patients with surgically treated aortic aneurysms

In the present study, biplane transoesophageal echocardiography (TEE) was scheduled as part of an aneurysm surveillance programme during routine ambulatory follow-up of 37 patients following aortic aneurysm surgery. Time from surgery ranged from 3-72 months. Twenty-two patients had had aortic dissection and 15 non-dissecting aneurysms. Nineteen patients received an interposition graft of the ascending aorta, 12 valved conduit and six an interposition graft of the descending thoracic aorta. TEE showed enlargement of the sinus of Valsalva > 45 mm in seven patients. Dilatation > 45 mm of one or more aortic segments was found in four patients. An intimal flap was present in all patients, with primary aortic dissection if the initial dissection extended beyond the replaced segment. This was the case in 17 of 22 patients with aortic dissection. One to four intimal tears were identified in 15 of these patients. In all patients with intimal tears, flow was detected by colour flow Doppler in the false lumen. Thrombus formation was nil or minimal in the false lumen in 12 patients. TEE significantly influenced further management in 14 of 37 patients (38%). More frequent follow-up was scheduled in eight patients. Aortic surgery was performed electively for the second or third time in six patients based on TEE findings. We conclude that after surgical repair of aortic aneurysm, the incidence of pathological findings by TEE is high. These may have significant influence on further patient management and emphasize the need for careful follow-up.

Surgical treatment of type A aortic dissections. Results with profound hypothermia and circulatory arrest

Type A aortic dissection still presents an emergency situation in cardiac surgery that is associated with high morbidity and mortality rates. There has been a significant improvement in the surgical outcome since the introduction of deep hypothermia and circulatory arrest. In this study, we discuss our results after operative repair of ascending aortic dissections, using deep hypothermia and circulatory arrest. This study presents the results of 67 patients (43 men, 24 women) from 18 through 81 years of age (mean, 54 years) who underwent surgery for type A dissecting aneurysm over a period of 4 years. Type A dissection (52 acute and 15 chronic cases) was due to Marfan syndrome in 12 patients, to atherosclerotic disease of the aorta in 27 patients, and to traumatic injury in 1 patient. Hypertension as the only pathologic finding was observed in 27 patients. Deep hypothermia (confirmed by isoelectric electroencephalogram) and circulatory arrest were induced in all patients. Two patients died intraoperatively due to massive bleeding (intraoperative mortality, 3%). The 30-day mortality rate was 30% (n = 20). Causes of perioperative deaths in order of frequency were multi-organ failure (n = 11), myocardial infarction (n = 2), postoperative bleeding (n = 2), cerebrovascular insult (n = 2), and sepsis (n = 1). The mean intensive care unit stay of the surviving 47 patients (72%) was 8 days, followed by a mean of 21 additional days in the hospital. Our experience with profound hypothermia and circulatory arrest, used in combination with coated grafts, supports our conviction that this is the method of choice for the treatment of type A dissecting aneurysm.

Elective surgery for blunt cardiac trauma

The cases of eight patients who underwent elective surgery for blunt cardiac trauma are presented. All but one experienced multiple trauma and the median Injury Severity Score was 26 (range, 18-59). A posttraumatic cardiac defect was diagnosed from 1 day up to 6.5 years (median, 3 weeks) after the accident. These included mitral regurgitation (n = 4), ventricular septal defect (n = 2), atrial septal defect with mitral regurgitation (n = 1), and ventricular aneurysm (n = 1). Elective cardiac surgery was performed from 4 weeks up to 12 years after the traumatic event (median, 18.5 months). A history of blunt chest trauma requires careful clinical follow-up supported by echocardiography in asymptomatic patients. Surgical therapy is performed according to standard techniques and the results are comparable with those of non-trauma surgery.

Thoracoabdominal aneurysm repair: spinal cord protection using profound hypothermia and circulatory arrest

Between January 1991 and February 1993, 14 patients (11 male, 3 female) between 21 and 79 years of age (median 50 years) underwent reconstruction of the thoracic (n = 7) and thoracoabdominal aorta (n = 7). Four patients had previously undergone operation of the ascending aorta, and in three patients coronary artery bypass grafting had previously been performed. All patients were operated on a via a posterolateral thoracotomy using cardiopulmonary bypass with continuous blood cardioplegia and hypothermic circulatory arrest (11 degrees C nasopharyngeal temperature, flat-EEG). All patent lower intercostal and lumbar arteries (T3 to L5) were reimplanted. The 30-day mortality after repair of the thoracic aorta was 0%; after replacement of the thoracoabdominal aorta, mortality was 28.5% (n = 2). One patient died 70 days after replacement of the thoracic aorta as a consequence of a perioperative stroke. None of the surviving 11 patients developed a permanent neurological deficit or renal or cardiac dysfunction. The average intensive care stay was 6 days for patients after replacement of the thoracic aorta and 18 days for patients after replacement of the thoracoabdominal aorta. Our results suggest that use of elective hypothermia and circulatory arrest for spinal cord protection is highly effective. We, therefore, recommend this method for complex reconstructions of the thoracoabdominal aorta.

Aprotinin does not decrease early graft patency after coronary artery bypass grafting despite reducing postoperative bleeding and use of donated blood

Forty-five male patients with planned coronary artery bypass operation were randomized in a double blind fashion to receive either 6 million kallikrein inactivator units of aprotinin (high-dose group), 2 million kallikrein inactivator units of aprotinin (low-dose group), or placebo (control group). Postoperative bleeding was significantly decreased in both aprotinin groups in comparison to that in the control group (590 ml [290 to 1800 ml] high-dose group and 650 ml [280 to 1900 ml] low-dose group versus 920 ml (350 to 2700 ml) control group, p < 0.001). There was no difference between the two aprotinin groups. The need for postoperative blood transfusion was significantly lower in the aprotinin groups (1.46 [0 to 4] blood units high-dose group and 1.65 [0 to 5] blood units low-dose group versus 2.43 [0 to 7] blood units control group, p < 0.05). All patients underwent coronary angiography between the seventh and twelfth postoperative day. No difference was found among the three groups in patency of vein grafts-93.8% in the high-dose group, 94.5% in the low-dose groups, and 93.3% in the control group. Therefore, aprotinin significantly reduced postoperative bleeding and transfusion requirement after coronary artery bypass grafting without influencing early graft patency.

Sinus of Valsalva aneurysm: a late complication after repair of ascending aortic dissection

Surgical advances and the introduction of new more rapid and accurate diagnostic techniques have led to significant improvement in the survival of patients with aortic aneurysms. However, considerable long-term morbidity and mortality remains a concern. In the present study we report on the occurrence of sinus of Valsalva (SV) aneurysm after repair of the ascending aorta for aortic dissection as a significant long-term complication. Since transesophageal echocardiography (TEE) became available it has been used for the follow-up of 33 hospital survivors after ascending aortic replacement for a mean of 27 +/- 20 months. Those patients who received a valved conduit were excluded from this analysis. The aortic valve was conserved in 22 patients: 17 had a dissecting aneurysm involving the ascending aorta and 4 patients non-dissecting aneurysms. A sinus of Valsalva diameter > 45 mm was considered an aneurysm and was found in a total of 7 patients (33%), 5 being patients with aortic dissection. The overall reoperation rate on account of SV aneurysms was 24%. We conclude that SV aneurysm is a significant long-term complication of patients after repair of the ascending aorta. In the light of these results we have changed our operative policy of repair to include resorcin glue as a reinforcing agent or to perform more extensive repair.

Anomalous origin of the left coronary artery: a review of surgical management in 13 patients

Over the last decades, surgical management of anomalous left coronary artery originating from the pulmonary artery (ALCAPA) has seen a considerable evolution. Between 1965 and 1992, 13 children with age at operation ranging between 2 months and 11 years (mean 23 months) underwent one of 5 different surgical procedures: ligation (n = 3), direct aortic reimplantation (n = 7), subclavian (n = 1) or internal mammary (n = 1) artery anastomosis, or modified aortic implantation (Vigneswaran-procedure, n = 1). There were 3 early and one late deaths resulting in an overall mortality of 30.7%. Mortality was 66.7% in the ligation group, and 20% in the revascularization group (28.6% in the subgroup with direct aortic implantation). The one late death occurred 6 months after ligation. Follow-up ranges between 3 months and 21 years, mean 7.3 years. All but one survivors are in NYHA functional class I. Following operative correction, there was clear improvement in left ventricular performance. Our data give reason to suggest ALCAPA to be more frequent than considered so far. Early surgery is recommended in all patients with ALCAPA, regardless of age or symptomatic status. Reestablishment of a two-coronary system is considered the procedure of choice. All survivors require long-term follow-up controls of early recognition of residual or progressive cardiac problems.

Correlation of atrial natriuretic peptide and cyclic guanosine monophosphate plasma concentrations in patients with heart disorders during rest and exercise

The concentration of atrial natriuretic peptide was measured in order to evaluate its importance in patients suffering from a variety of cardiac diseases. There was a correlation between plasma concentrations of atrial natriuretic peptide and its "second messenger" cyclic guanosine monophosphate (cGMP) in all of the cases examined. We investigated the relationship between atrial natriuretic peptide and cGMP plasma concentrations during rest and exercise in comparison with the scintigraphically assessed left- and right-ventricular ejection fraction in patients with chronic heart disease (n = 20), and after orthotopic heart transplantation (n = 16); plasma concentrations were also measured in healthy controls (n = 14). Atrial natriuretic peptide and cGMP concentrations showed a similar correlation during rest and exercise with r = 0.74 and r = 0.81, respectively. With the exception of patients after heart transplantation, a significant negative correlation was seen between the left ventricular ejection fraction and atrial natriuretic peptide or cGMP plasma concentrations during rest conditions (r = 0.76 or 0.58, respectively). No correlation was apparent between plasma concentrations of atrial natriuretic peptide or cGMP and the left- or right ventricular ejection fraction during exercise. The concentrations of atrial natriuretic peptide and cGMP in plasma differed significantly between healthy controls and patients during rest and exercise. It is noteworthy that atrial natriuretic peptide and cGMP concentrations were markedly higher in patients after heart transplantation than in patients suffering from chronic heart disease. Our results indicate that plasma atrial natriuretic peptide and cGMP concentrations are sensitive markers of cardiac impairment.

Early activation of hemostasis during cardiopulmonary bypass: evidence for thrombin mediated hyperfibrinolysis

In 14 consecutive patients undergoing cardiopulmonary bypass for coronary bypass surgery the time course of coagulation and fibrinolysis markers were measured, e. g. plasma levels of thrombin-antithrombin III (TAT) complexes, cross-linked fibrin degradation products (XIFDP) and plasmin-alpha 2-antiplasmin complexes (PAP). TAT levels exceeded the 90% baseline percentile already during CPB (after opening of aortic clamp) in 10 patients, whereas PAP and XIFDP exceeded their 90% percentile in only one patient at this time. Concerning fibrinolysis markers PAP and XIFDP the majority of patients showed elevations higher than their 90% baseline percentile only 1 h postoperation. Correlation analysis revealed significant dependencies between TAT levels during and at the end of CPB and PAP levels 1 h postoperation (R = 0.55 and R = 0.56 respectively). Furthermore, 1 h postoperation XIFDP levels were significantly correlated with both TAT and PAP. Peak XIFDP levels at the same time correlated with blood loss via thoracic drains (R = 0.56). Thus, we suggest that hyperfibrinolysis in patients undergoing CPB is at least partly due to hypercoagulation. Clinically, this may implicate that intensified anticoagulation could prevent hyperfibrinolysis and reduce postoperative blood loss.

New aspects of the degeneration of bioprosthetic heart valves after long-term implantation

Bioprosthetic heart valves removed 76 to 150 months after implantation were morphologically investigated to correlate structural alterations with clinical failure modes. Traditional morphologic methods of evaluating valvular heterografts, such as microradiography and electron microscopy, were complemented by undecalcified ground sections, a new technique for analyzing the distribution of mineral deposits. Apart from well-investigated mechanisms that accelerate tissue degeneration, our observations point to additional facts: (1) phagocytosis of collagen fibrils and elastic material by macrophages and foreign body giant cells in areas near tears and perforations and (2) initial calcification indicated by delicate crystals in the intercellular space arranged in close relation to the periodicity of the cross-striation pattern of collagen fibrils. The present report not only calls attention to degenerative changes that are enhanced by mechanical stress but also underlines phagocytosis as an important mechanism in the destruction of bioprosthetic heart valves.

Transesophageal echocardiography in the emergency surgical management of patients with aortic dissection

The diagnostic accuracy and benefit of transesophageal echocardiography were investigated in 32 patients with suspected aortic dissection. Results of transesophageal echocardiography were compared with surgical assessment. The Stanford classification was used for differentiation of dissection type. Examination time was 5 to 15 minutes. Twenty-eight patients were correctly identified to have aortic dissection; four patients had nondissecting aneurysms of the ascending aorta. Both sensitivity and specificity for detection of aortic dissection were 100%. Type of dissection was misdiagnosed in one patient. Classification of dissection type was correct in 96%. The primary entry site was correctly identified in 25 patients (89%). Aortic regurgitation was found in 57% of patients. Pericardial effusion was detected in 21%, with tamponade in one patient. Myocardial infarction was suggested by transesophageal echocardiography in 7%, and 14% had significantly reduced left ventricular function. Eight patients underwent operation based on transesophageal echocardiography alone. Intraoperative transesophageal echocardiography, performed in 20 patients, verified retrograde flow in the true lumen after femoral cannulation. Transesophageal echocardiography documented postrepair persistence of the intimal flap in aortic segments that were not operated on in all patients. Secondary tears and flow in the false lumen were detected in 35% of patients. We conclude that transesophageal echocardiography allows expedient and accurate diagnosis and classification of aortic dissection, and we recommend it as the primary bedside diagnostic modality. It can especially identify patients requiring surgical intervention without further delay caused by other diagnostic procedures.

Decreasing use of donated blood and reduction of bleeding after orthotopic heart transplantation by use of aprotinin

Twenty patients undergoing orthotopic heart transplantation were randomized preoperatively to receive either the serine proteinase inhibitor aprotinin in a low dose (560 mg; n = 10) or a placebo (control group, n = 10) at the time of transplantation. Blood loss 24 and 48 hours after transplantation was significantly lower in the group treated with aprotinin (i.e., 510 ml vs 820 ml, p less than 0.01, and 690 ml vs 1000 ml, p less than 0.03, respectively. Accordingly, the aprotinin group required significantly less transfused blood in the first 48 postoperative hours 0 to 250 ml versus 0 to 1000 ml (p less than 0.04). Seventy percent of the patients treated with aprotinin underwent transplantation without the need of nonautologous blood, compared with only 30% in the control group.

The monoclonal HBA-71 antibody modulates proliferation of thymocytes and Ewing's sarcoma cells by interfering with the action of insulin-like growth factor I

The monoclonal HBA-71 antibody recognizes a Ewing's sarcoma associated antigen, which is also highly expressed on the cell surface of human cortical thymocytes and islets of Langerhans among normal tissues. The antibody was found to inhibit partially the growth of ES tumor cell lines and to trigger proliferation in thymocyte cultures. The influence of growth factors and the effect of the HBA-71 antibody was further investigated in the present study. The growth of ES tumor cells was demonstrated to be dependent on the presence of insulin-like growth factor I or insulin. The HBA-71 antibody (25 micrograms/ml) enhanced the growth stimulatory effect of IGF-I under serum-free conditions. The expression of the HBA-71 epitope is modulated positively by IGF-I and insulin and negatively by dexamethasone and human growth hormone in ES/PNET tumor cells and thymocytes. IGF-I either alone or in combination with HBA-71 stimulated the proliferation of thymocytes under serum-free conditions whereas in complete medium, IGF-I stimulated thymidine incorporation and the HBA-71 antibody either alone or in the presence of IGF-I showed inhibitory activity most likely due to down-regulation of the receptor. These data demonstrate the important role of IGF-I in the growth of ES/PNET tumor cells as well in the proliferative activity of HBA-71 positive normal thymocytes. The biological activity of IGF-I in malignant thymocytes, pancreas tumors, fetal muscle, brain, granulosa and Sertoli cells has been documented in the literature.(ABSTRACT TRUNCATED AT 250 WORDS)

Effect of intraoperative aprotinin administration on postoperative bleeding in patients undergoing cardiopulmonary bypass operation

To study the hemostyptic effect of aprotinin (Trasylol) in patients undergoing extracorporeal circulation for coronary artery bypass operations, we randomized 12 of 24 patients to receive aprotinin in high dosage (about 800 mg) during extracorporeal circulation. From the resulting two groups each, one patient was excluded from the study because of postoperative myocardial infarction (control group) and surgical hemorrhage (aprotinin group) leading to a second operation. Although heparin was used for anticoagulation in all 22 patients, all had a marked increase in plasma levels of thrombin-antithrombin III complexes during extracorporeal circulation, indicating an intravasal activation of coagulation. By monitoring the plasma levels of fibrin degradation products in patients without aprotinin therapy, we recorded a concomitant hyperfibrinolysis significantly less pronounced in patients receiving aprotinin (p less than 0.005). The mean total postoperative blood loss was lower in patients receiving aprotinin (620 ml) than in control patients (1000 ml; p less than 0.03). The results confirm previous reports of a hemostyptic effect of aprotinin in cardiac operations. This effect is probably due to a prevention of hyperfibrinolysis.

Basic principles of cardioplegic management in donor heart preservation

The primary factor limiting the number of heart transplantation performed is the lack of adequate donor hearts. One of the main factors contributing to this is the relatively short period a donor heart can be preserved. Clinical studies demonstrate that ischemic times over five hours lead to early heart failure after transplantation. A considerable increase in preservation time would be necessary to enlarge the donor pool. In spite of intensive research, it is not yet possible to increase the preservation period above four hours, which was achieved in 1978. An increase of the cold ischemia period to more than four hours without the risk of transplanted heart damage may only be achieved by improving cardioplegic management.

Beta 2-microglobulin. A reliable parameter for differentiating between graft rejection and severe infection after cardiac transplantation

We investigated the role of beta 2-microglobulin as a noninvasive parameter to monitor acute rejection and severe infection in 45 consecutive heart transplant recipients. Endomyocardial biopsy revealed moderate (41 patients) or severe (three patients) rejection in 44 patients. Severe infections of bacterial septicemia (11 patients), bronchopneumonia (two patients), and viral infection (seven patients) were detected by a meticulous schedule of various clinical and laboratory tests. beta 2-Microglobulin levels in serum, generally corrected for serum creatinine, were significantly elevated in patients with infections (median, 6.3 mg/l; range Q10-Q90, 3.47-10.27 mg/l) compared with levels in patients with rejection (p less than 0.0001) or in patients in obviously good condition (p less than 0.0001). At the onset of acute rejection, the median corrected beta 2-microglobulin serum level was 1.56 mg/l (range Q10-Q90, -0.05-3.46 mg/l) and was significantly different from the control group (p less than 0.01). In addition, density function and empirical quantile analyses allowed us to define ranges of beta 2-microglobulin levels that would differentiate between rejection (2.05-3.46 mg/l) and infection (greater than 3.46 mg/l). With these values, sensitivity and specificity were 0.9 and 0.938 for detection of infection and 0.23 and 0.925 for detection of rejection, respectively. By means of beta 2-microglobulin, two cases of infection were misinterpreted as rejection (10%), and four of 44 rejections were mistaken for infections (9%). We conclude that measurements of beta 2-microglobulin may improve the management of heart transplant patients.

Ewing's-sarcoma-associated HBA-71 tumor antigen represents a new differentiation marker of human thymocytes

The monoclonal HBA-71 antibody recognizes a new human tumor-associated antigen of Ewing's sarcoma and peripheral neuroectodermal tumors, which is also expressed in some normal tissues, including thymus, islets of Langerhans, ependyme, adenohypophysis, Sertoli/Leydig and granulosa cells. Besides a tumor-specific reciprocal chromosomal translocation t (11:22), the expression of the HBA-71 antigen is the only marker which can be used for reliable differential diagnosis of these rare malignancies of childhood and adolescence among other small round cell tumors. The HBA-71 antigen is further characterized here by ultrastructural, functional and cell-matrix interaction studies. In immunohistochemical staining the HBA-71 reacted with the cell surface of human cortical thymocytes. The HBA-71 antigen was also found to be localized at the cell-surface glycocalyx of tumor cells using immunogold staining and electron microscopy. A panel of additional monoclonal antibodies with reactivity patterns similar to those of the HBA-71 antibody was obtained by immunization of mice with ES cell lines and boostering with thymocytes. The HBA-71 antibody triggers proliferation of thymocytes and to a lesser extent also stimulates peripheral mononuclear blood cells. Antibody-induced thymocyte cultures exhibit the phenotype of immature, CD3low thymocytes with uniform and stable expression of the HBA-71 antigen. In contrast to the thymocytes the HBA-71 antibody has an inhibitory effect on the continuous growth of the HBA-71+ tumor cell lines. The HBA-71 antigen may be involved in the regulation of growth of the positive normal and malignant tissues. Positive modulation of the antigen expression was induced in Ewing's sarcoma cell lines in response to insulin, insulin-like growth factor I (IGF-I) and by interaction of the cells with the extracellular matrix.

[The course of atrial natriuretic peptide, aldosterone and antidiuretic hormone in normal pregnancy]

Atrial natriuretic peptide (ANP), consisting of 28 aminoacids, is a recently discovered cardiac hormone involved in blood-volume homeostasis. Pregnancy is associated with an increase in blood volume expansion, therefore an increase in ANP-concentration would have been expected. To test this hypothesis ANP, Aldosterone and Vasopressin, concentrations of 229 women with normal pregnancies at different gestational ages were measured and compared with values found in a non-pregnant control group of 24 women. Mean plasma ANP was increased during pregnancy, but significant differences were noted only after 36 weeks of gestation. Also plasma aldosterone increased significantly during pregnancy, whilst vasopressin levels showed no significant change compared to the non-pregnant group.