Biomedical subjects
Publications and source records attributed to M Schlemmer.
Here, we report the alterations in renal water handling in healthy volunteers during a 6 h thermoneutral water immersion at 34 to 36 degrees C. We found that water immersion is associated with a reversible increase in total urinary AQP2 excretion.
MR-thermometry methods have been developed for the guidance and control of thermal therapies such as thermal ablation or regional hyperthermia. However, they are limited to the measurement of temperature changes and, thus, cannot be used to assess absolute temperature values. Paramagnetic thermosensitive liposomes are innovative contrast agents offering the potential to overcome these limitations. They are composed of a gadolinium- or manganese-based compound enclosed by a phospholipid membrane with a distinct gel-to-liquid crystalline phase transition temperature (Tm). At this temperature, the phospholipid membrane changes from a gel-phase to a liquid-crystalline phase which is associated with an increased transmembrane permeability towards solutes and water. Under these conditions, both types of paramagnetic thermosensitive liposomes demonstrate a significant increase in longitudinal (T1) relaxivity, attributed to the release of paramagnetic material from the liposome and/or to the increased water exchange rate between the liposome interior and exterior. Paramagnetic thermosensitive liposomes have already been successfully studied in animal models and have demonstrated a clear correlation between tissue temperature changes and signal intensity changes in MRI. Nevertheless, before entering clinical trials they have to be studied in more detail with regard to dose, pharmacokinetics and toxicity.
Clinical hyperthermia with controlled alteration of temperature (40 to 44 degrees C) in the target area is used in interdisciplinary treatment concepts for tumor treatment in combination with radiation and/or radiotherapy. Besides the direct cytotoxic power of hyperthermia there is an immunomodulatory effect and a radiation and chemotherapy sensitizing effect in the heated tissue. Clinical hyperthermia is an invasive or non-invasive supply of energy to the body of the patient, which leads to an artificial heating of the tumor and the surrounded tissue. The clinical hyperthermic procedures should take into account the oncologic disease and its pattern of organ involvement. There are three different types of hyperthermia: local hyperthermia (LHT), regional hyperthermia (RHT) and part body hyperthermia (PBH). PBH is used to heat regions of the body in case of metastatic disease, e. g. to the abdomen. I and phase II trials could show that the effects of radiation and chemotherapy can be altered by the simultaneous addition of hyperthermia. Data of trials involving skin metastasis in malignant melanoma, local relapse in breast cancer, tumors of the head and neck with regional lymph node metastasis, as well as trials in colorectal tumors, bladder cancer, pancreatic cancer, cervical cancer and sarcoma are presented. The results shows, that response to treatment can be improved by hyperthermia.
PURPOSE: To evaluate the efficacy and safety of the combination of ICE (ifosfamide 1.5 g m(-2), carboplatin 100 mg m(-2) and etoposide 150 mg m(-2), days 1-4, q 28 days, G-CSF 5 microg kg(-1) starting from day 6) alone and in combination with regional hyperthermia (RHT) in soft tissue sarcoma (STS) refractory to previous standard doxorubicin-ifosfamide-based chemotherapy. PATIENTS AND METHODS: Twenty patients with advanced STS of different histological sub-types were treated with the ICE regimen with 13 patients receiving additional RHT. A median of four courses of ICE were administered with RHT on days 1 and 3 (60 min, T(max) 42 degrees C). RESULTS: The objective response rate was 20%, with four partial responses (all treated with hyperthermia). In addition, two patients showed mixed responses and five patients stable disease. After a median follow-up time of 15 months, median time to progression was 6 months. Progression free rate estimates were 60% and 45% at 3 and 6 months, respectively. Median overall survival for all patients was 14.6 months. CONCLUSION: These results suggest that ICE alone or combined with RHT shows activity as second-line therapy in doxorubicin-ifosfamide-refractory STS.
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HISTORY AND ADMISSION FINDINGS: A 35-year-old man reported progressive exercise dyspnea, decreased exercise tolerance and weight loss of 10 kg in 2 months. Imaging tests demonstrated a tumor of maximally 7 cm diameter in the region of the left atrium. Histologically it was a poorly differentiated leiomyosarcoma G 3, which could not be completely resected (R 2 resection). SUBSEQUENT INVESTIGATION: Six weeks after surgical resection a rapidly growing tumor, maximally 7.5 cm in diameter, was visualized at the right lateral region of the left atrium. It filled it almost completely and extended via the right upper pulmonary vein to the right hilus. TREATMENT AND COURSE: As part of a multimodal therapeutic approach he was given 6 cycles of chemotherapy (doxorubicin and ifosfamide), bringing about significant reduction of the tumor size. The tumor was then completely resected, followed by an orthotopic heart transplantation with right pneumonectomy. The resected surgical specimen indicated complete remission, no vital tumor cells being demonstrated. No tumor recurrence or distal metastasis was seen during a follow-up period of 36 months. The patient died from right heart failure with advanced pulmonary hypertension 45 months after the diagnosis had first been made, 37 months after the cardiac transplantation.
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For high-risk soft tissue sarcomas (HR-STS) of adults, new treatment strategies are needed to improve outcome with regard to local control and overall survival. Therefore, systemic chemotherapy has been integrated either after (adjuvant) or before (neoadjuvant) optimal local treatment by surgery and radiotherapy in HR-STS. The combination with regional hyperthermia as a new treatment strategy seems to open a new therapeutic window.
PURPOSE: For high-risk soft tissue sarcoma (HR-STS) of adults new treatment strategies are needed to improve outcome with regard to local control and overall survival. Therefore, systemic chemotherapy has been integrated either after (adjuvant) or before (neoadjuvant) optimal local treatment by surgery and radiotherapy in HR-STS. METHODS AND RESULTS: The Soft Tissue and Bone Sarcoma Group (STBSG) of the European Organization for Research and Treatment of Cancer (EORTC) is conducting an open randomized trial of adjuvant chemotherapy in high-grade primary or recurrent STS at any site (EORTC 62931). In all cases primary surgery should be curative in intent. All eligible patients are randomized after completion of definitive surgery to receive either radiotherapy alone with no further treatment (observation arm) or five cycles of doxorubicin (70 mg/m(2)) plus ifosfamide (5 g/m(2)) using G-CSF to support dose intensity followed by radiotherapy (chemotherapy arm). This more aggressive chemotherapy regimen within an adjuvant setting might retain sufficient antitumor activity to convert response rates into survival benefit. At present more than 220 patients have been recruited for this trial. To explain the rationale for the EORTC 62931 protocol, reported results of other clinical adjuvant protocols including a meta-analysis are given. In close collaboration with the European Society of Hyperthermic Oncology (ESHO) the STBSG has also initiated a randomized trial of neoadjuvant chemotherapy in primary or recurrent HR-STS as an EORTC Intergroup study. According to the inclusion criteria as defined (tumor size >or=5 cm + grade II or III + deep location + extracompartmental extension) for the EORTC 62961/ESHO RHT-95 Intergroup study, the majority of patients with HR-STS recruited for this pre- and postoperative multimodality treatment protocol cannot be cured by standard procedures. All eligible patients are randomized to receive either four cycles of EIA (etoposide 250 mg/m(2) + ifosfamide 6 g/m(2) + doxorubicin 50 mg/m(2)) within 12 weeks (chemotherapy arm) or the same EIA regimen combined with regional hyperthermia (RHT + chemotherapy arm). The patients then receive optimal local treatment using adequate surgery immediately followed by radiotherapy. Thereafter an additional four cycles of EIA chemotherapy are given with or without RHT according to the initial randomization. At present more than 150 patients have been recruited for this trial. The integration of RHT as a new potent treatment modality if combined with EIA chemotherapy as first-line treatment for well-defined risk groups is based upon encouraging long-term results of phase II studies both in pretreated patients with HR-STS and in those with locally advanced disease. CONCLUSIONS: In summary, significant prognostic variables recognized for patients with STS have been addressed in the design of two open phase III clinical trials on adjuvant and neoadjuvant chemotherapy. The best chance for offering such treatment strategies following evidence-based medicine criteria to eligible patients with HR-STS depends upon early contact with the coordinator of the individual protocol prior to any treatment.
UNLABELLED: We report on the rare case of a 4-year-old boy with patent ductus venosus and pulmonary hypertension presenting with progressive fatigue, tachypnoea at rest and tachycardia. Cardiac catheterisation revealed suprasystemic pressure in the pulmonary arteries with severely elevated pulmonary vascular resistance. In order to reduce the diameter of the ductus venosus, a stent was implanted interventionally, which closed, as expected, spontaneously 2 years later. Pulmonary arterial pressure and pulmonary vascular resistance decreased significantly and the general condition of the boy improved dramatically. CONCLUSION: To the best of our knowledge, this represents the first report of successful interventional stent occlusion of a patent ductus venosus associated with severe pulmonary hypertension. The future will tell whether this intervention is curative or represents a bridging procedure for subsequent liver transplantation.
Aortopulmonary collateral arteries sometimes complicate cyanotic congenital heart defects. Combined with a relevant left-right shunt, this could result in massive airway bleeding during and after corrective surgery. A preoperatively diagnosed 1.2 mm small aortopulmonary collateral artery in a newborn suffering from transposition of the great arteries caused life-threatening airway bleeding during surgery. Postoperative extracorporeal membrane oxygenation (ECMO) was necessary, and coil embolization was performed on ECMO to terminate pulmonary bleeding.
UNLABELLED: Glenn shunt and Fontan procedure, the most widely used surgical procedures in congenital heart anomalies, may be associated with abnormal pulmonary blood flow patterns and the development of pulmonary arteriovenous fistulae. METHODS: This study quantified pulmonary and whole-body blood flow using the microsphere technique by sequential injection of 99mTc microspheres into upper and lower limb veins and performing planar lung imaging in four projections and anterior and posterior whole-body scans in 46 patients with either Glenn shunt or Fontan procedure. The right-to-left shunt volume was estimated by a brain and kidneys-to-lungs ratio and compared with calculations from the whole-body scans. RESULTS: In 31 of 46 patients, the blood from the superior vena cava was drained preferentially into the right lung (75%+/-19%). The inferior venous system was drained equally into both lungs. The right-to-left shunt volume was 24%+/-12% after injection into the superior caval system, 50%+/-18% after injection into the inferior caval system. A subgroup of patients who had undergone a palliative Blalock-Taussig shunt (BTS) before the final surgery showed a perfusion pattern that was not known after pulmonary angiography or contrast echocardiography: 15 of 24 patients with BTS had hypoperfusion of the upper lobe on the side of the BTS after injection into the arm vein and corresponding normal perfusion or hyperperfusion when injected into the foot vein. CONCLUSION: Lung perfusion scintigraphy after tracer application into the superior and inferior caval systems detects more abnormal pulmonary blood flow patterns than contrast echocardiography and is the only procedure able to quantify right-to-left shunt volume individually for the superior and inferior caval systems. Thus, this diagnostic technique should be part of the routine follow-up in children after Glenn shunt or Fontan procedure.
Aortopulmonary collaterals occur in a variety of congenital heart diseases, in chronic pulmonary infection and abscesses, in association with lung tumors, and after multiple pulmonary emboli. In patients with congenital cyanotic heart disease aortopulmonary collaterals mainly occur in conditions with reduced pulmonary blood flow. We investigated 12 preterm low-birth-weight infants, gestational age 29.3+/-3.3 weeks, with respiratory failure who suffered from moderate to severe chronic lung disease after a period of mechanical ventilation. All patients developed aortopulmonary collaterals after closure of a patent ductus arteriosus. Aortopulmonary collaterals could be displayed clearly by color Doppler echocardiography and originated mainly from the descending aorta or the aortic arch. Hypoxic and hypercapnic episodes favored the development of aortopulmonary collaterals, which disappeared after pulmonary hemodynamics and respiratory function had improved. In only one patient coiling of a large col lateral vessel had to be performed. Systemic-to-pulmonary collateral vessels potentially aggravate chronic lung disease by increasing collateral pulmonary blood flow and reducing lung compliance. We conclude that aortopulmonary collaterals occur in bronchopulmonary dysplasia and can cause major problems in ventilated premature infants. Echocardiographic evaluation is important to prevent aggravation of chronic lung disease of infants at risk.
We report about a 66-year old patient with Non-Q-wave infarction in coronary artery two-vessel disease. During an echo- and transesophageal multiplane echocardiography preoperatively before a coronary artery bypass surgery a right atrium septal tumor of unknown form was discovered. The computerized axial tomography (CAT) and nuclear magnetic resonance (NMR) scans did not demonstrate extracardiac pathologic findings. A transesophageal echocardiography-guided biopsy of the right atrial septum over the vena femoralis and the right atrium enabled intra vitam a very early diagnosis of high malignant B-cell Non-Hodgkin-lymphoma without the need for thoracotomy. The diagnosis was confirmed histopathologically and immunohistochemically and early treatment with cytostatic therapy could begin. To our knowledge the transesophageal echocardiography-guided biopsy has never been described in the worldwide literature.
A process of adaptation of the cardiovascular system occurs during pregnancy, entailing physiologic changes. In women with congenital heart disease these changes lay a great burden on the cardiovascular system. Therefore there is an increased risk for mother and fetus, depending on the form of congenital heart disease, preceding operations and the grade of maternal hypoxemia. Overall, the maternal mortality is low, but in certain forms of congenital heart disease the mortality rate can rise to 50%. Infective endocarditis and anticoagulation therapy represent further problems for mother and fetus. It is the duty of the cardiologist, general practitioner and obstetrician to counsel the patient before conception on potential complications and risks of pregnancy, expected physical deterioration of the mother, as well as possible malformations of the child, including the recurrence risk of congenital heart disease. If pregnancy is contraindicated because of the severity of the heart disease, the patient has to be advised about reliable contraceptive methods tailored to her individual needs and their risks, including possible endocarditis, bleeding under anticoagulation therapy, thrombosis, toxic shock syndrome etc.
From July 1987 to December 1992, 52 patients underwent balloon-angioplasty of aortic coarctation at three units of pediatric cardiology in Austria (Graz = 35 patients, Innsbruck = 15 patients, and Vienna = 2 patients). 35 patients had postoperative and 17 had native coarctation. Mean age at intervention was 7 10/12 years with 2 patients under 1 year and 5 patients over 18 years old. The mean relation balloon diameter-coarctation diameter was 2.6 +/- 0.9. The blood pressure gradient between upper and lower extremities decreased from a mean of 44 +/- 16 mm Hg to 15 +/- 13 mm Hg (p < 0.0001). The diameter of the stenosed segment was increased from 5 +/- 3 mm to 8.5 +/- 3.5 mm (p < 0.0001). Native coarctation showed a significantly better result in respect to decrease of the gradient (36 +/- 12 mm Hg) than did postoperative coarctations (25 +/- 19 mm Hg) (p < 0.03). 13 patients did not respond adequately to angioplasty. 10 patients out of this group had tubular narrowings and belonged to the group of postoperative coarctations, whereas localized stenoses in native coarctations gave the best results. Localized wall irregularities were found in 4 patients with native coarctation. Balloon angioplasty of postoperative and native coarctations in childhood and adolescence is a secure and effective means of treatment and should be considered as therapy of first choice. The best results can be found in the group of the circumscript type of stenoses in native coarctation, whereas long and tubular stenoses in the group of postoperative coarctations give less satisfying results.
The hemodynamic effect of long-term nifedipine medication was studied in 10 children, 3-12 years of age, five with ventricular septal defect and five with complete atrioventricular septal defect; all had Eisenmenger's reaction, seven also had Down's syndrome. They underwent heart catheterization prior to and during 1-4 years of nifedipine therapy. Fick's principle was used to calculate the ratio of pulmonary arterial pressure to aortic pressure (PAP/PAO), the ratio of pulmonary flow to aortic flow (QP/QS), as well as the ratio of pulmonary vascular resistance to aortic vascular resistance (RP/RS). In the seven children under 8.8 years, nifedipine caused a significant drop in PAP/PAO (p less than 0.004), a slight increase in arterial O2 saturation, a significant increase in QP/QS (p less than 0.02), and a decrease in RP/RS (p less than 0.02). The nifedipine effect was age related. On nifedipine, breathing oxygen resulted in, independent of age, a significant increase in QP/QS (p less than 0.003) and a significant decrease in PAP/PAO (p less than 0.04) and in RP/RS (p less than 0.003). Direct O2 consumption measurements before and during oxygen breathing in six patients demonstrated no significant change in RP, RS, QP, or QS indices. Nifedipine had a relaxing effect on the pulmonary vascular bed, especially in the younger child with Eisenmenger's mechanism. On nifedipine therapy, O2 produced a more complex hemodynamic reaction that was not restricted to the pulmonary circulation alone.
Clinical experience with long-term nifedipine treatment in 23 patients aged between 1 1/12 and 14 8/12 years is reported. The cardiopulmonary diseases comprised primary pulmonary diseases with pulmonary hypertension (n = 4), congenital heart defects with intracardiac shunts and pulmonary hypertension which either were inoperable as a result of an Eisenmenger reaction (n = 7) or presented a high surgical risk (n = 5), or defects in which pulmonary hypertension did not regress despite corrective (n = 1) or palliative surgery (n = 3), and congenital defects without pulmonary hypertension (n = 3). Subjective improvement with an increase in physical performance was clearly observed in 15 cases. Echocardiography and cardiac catheter examinations showed no progression of the pulmonary arterial diseases, except in 1 patient with severe primary pulmonary hypertension and an 11-year observation period with nifedipine treatment during the last 4 years. No complications occurred during the 4 corrective operations. A patient aged 14 8/12 years with the Down syndrome and atrioventricular septal defect developed easily controllable heart failure during 7-day administration of nifedipine without additional cardiotherapy. 4 children initially suffered from flushed face and scalp, in one case with headache; 2 children reported fatigue. Long-term treatment with nifedipine should begin with strict 7-day supervision in hospital and possibly additional digitalization. Success of the treatment was determined by an improved quality of life in patients with primary pulmonary hypertension and inoperable defects, and by a reduced perioperative risk and postoperative regression of pulmonary hypertension in patients with operable defects.