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Biomedical subjects

M K Heinemann

Publications and source records attributed to M K Heinemann.

At least 19 recordsLinked to original sources
PubMed2005

Alternatively spliced transcripts of the thymus-specific protease PRSS16 are differentially expressed in human thymus.

The putative serine protease PRSS16 is abundantly expressed in the thymic cortex and the gene is encoded within the HLA I complex. Although its function is not yet defined, the very restricted expression points to a role in T-cell development in the thymus. In this study, we show that the PRSS16 mRNA is alternatively spliced to generate at least five transcripts. Apart from the full-length sequence, we found two other isoforms with all putative active site residues of the serine protease, suggesting that those variants may also be functional. Semi-quantitative analysis of the splice variants in different tissue samples revealed a strong correlation between the specific formation of alternatively spliced PRSS16 transcripts and the age and thymus pathology status of the donor. Newborn thymi express mostly the PRSS16-4 and -5 isoforms and lack the PRSS16-1 transcript, which appears around 2 years of age and stays until adulthood. Incidentally, thymi from myasthenia gravis (MG) patients with thymoma showed a marked decrease in the expression of the full-length PRSS16-1 and increased expression of the smaller isoforms. The data suggest a potential role of the PRSS16 isoforms in the postnatal morphogenesis of the thymus and in the thymus pathology related to MG.

Adult↗
PubMed2002

Successful repair of intraoperative type-A dissection in an infant.

A case of intraoperative type-A aortic dissection caused by partial displacement of the aortic cannula in a 6-month-old infant is presented, which was successfully managed by reapproximation of the dissected layers of the ascending aorta. At 1 year of follow-up the imaging studies show a normal appearance of the operation site.

Aorta↗
PubMed2001

[Treatment of supravalvular pulmonary stenosis after arterial switch operations (ASO)].

The aim of this study was to evaluate the incidence of postoperative pulmonary supravalvular stenosis in patients with d-TGA and to assess the rate of success or failure of balloon angioplasty. Out of 70 patients with d-TGA 67 patients underwent successful arterial switch operation. Twelve children developed severe supravalvular pulmonary stenosis with a peak gradient above 50 mmHg (range: 50-120 mmHg). In these patients 19 high pressure dilatations were performed up to a diameter of 130% of the native valve dimension. The mean age at angioplasty was 17 months (range: 3-36 months). Successful intervention was defined as a > 50% decrease of predilatation peak pressure gradient or right ventricular pressure < 50 mmHg. Dilatations were performed without complications. Complete resolution was primarily achieved in 1 patient. In 7 patients the pressure gradients could be reduced to 10-45 mmHg (mean: 25 mmHg). In another two patients a palliative stent-implantation into the pulmonary trunk was necessary to reduce the pressure gradient. Because unsuccessful intervention, two patients needed subsequent operation. During follow-up of 6-9 months after intervention severe restenosis occurred in 3 patients (2 after stent-implantation; 1 after re-re-dilatation) who then also needed operation. Balloon dilatation should be the first treatment in patients with pulmonary stenosis after ASO in TGA owing to the low complication rate and the potential benefit of this procedure. Recurrent and combined stenoses with narrow pulmonary valve annulus should be treated surgically.

Age Factors↗
PubMed2001

Ventricular septal defect closure in a neonate with combined methylmalonic aciduria/homocystinuria.

Methylmalonic acidemia with associated homocystinuria is a rare inborn error of amino acid metabolism affecting energy supply on the cellular level. Its effects on recovery from surgically induced organ ischemia are largely unknown. We report the successful closure of a nonrestrictive ventricular septal defect by following a normothermic strategy combined with ample metabolic substrate supply.

Amino Acid Metabolism, Inborn Errors↗
PubMed2001

Correction of anterior thoracic wall deformities: improved planning by means of 3D-spiral-computed tomography.

Surgical correction of anterior thoracic wall deformities is an extensive procedure with considerable operative trauma. The procedure can be markedly supported by means of preoperative 3D spiral-computed tomography for the purpose of improved preoperative planning in order to avoid unnecessary tissue mobilization. It is also helpful to enhance the patients' comprehension regarding the operative requirements.

Adolescent↗
PubMed2000

S-100 after correction of congenital heart defects in neonates: is it a reliable marker for cerebral damage?

BACKGROUND: Newborns undergoing cardiac operation may acquire some extent of neuronal damage. An early diagnosis is especially hard regarding neonates. In the past years, S-100 has been widely discussed as a marker revealing perioperative damage to the brain. METHODS: Sequential blood samples from 33 neonates undergoing repair of congenital heart disease were taken perioperatively. Samples of 12 healthy neonates were taken at birth as a control group. The newborns were divided into four groups: cyanotic and acyanotic disease operated on in deep hypothermic circulatory arrest, operation without deep hypothermic cardiac arrest, and operation without extracorporeal circulation. RESULTS: Even in healthy neonates, serum S-100 levels were at 10-fold values compared with adults. On admission, S-100 values in the operative groups were similar. During extracorporeal circulation, levels rose to a certain degree. Cyanotic newborns operated on in deep hypothermic cardiac arrest had significantly higher S-100 levels compared with acyanotic newborns also operated on in deep hypothermic cardiac arrest (p < 0.001). Two newborns who experienced seizures postoperatively had the highest absolute S-100 levels. One child with a poor neurologic outcome but no seizures did not have different values when compared with her group. CONCLUSIONS: In this study, S-100 seemed to be a possible marker for a certain degree of neurologic deficit after cardiac operation in neonates, especially regarding postoperative seizures. The missing peaks of this protein in one newborn with poor neurologic outcome show that it is not possible to exclude damage to the brain with normal postoperative values. These results suggest that the mechanism of cerebral damage and S-100 release into the blood in neonates with a developing central nervous system and blood-brain barrier is not fully understood.

Adult↗
PubMed2000

Successful weaning of a transplanted heart from biventricular assist device.

Exceptionally few cases worldwide have survived weaning from a biventricular assist device following heart transplantation in contrast to those who underwent early retransplantation. We present a successful outcome after biventricular assist device implantation following initial biventricular failure after heart transplantation. Weaning could be performed after 1 week, although pulmonary vascular resistance remained markedly elevated.

Adult↗
PubMed2000

Evaluation of protein S-100 serum concentrations in healthy newborns and seven newborns with perinatal acidosis.

UNLABELLED: We measured Protein S-100 serum levels in 66 healthy newborns during the first week of life and in 7 newborns with perinatal acidosis. Normal values (n = 66) constantly ranged between 0.66 and 3.33 microg/l (2.5 and 97.5 percentiles) during the evaluation period. CONCLUSIONS: Newborns with signs of hypoxic-ischaemic encephalopathy (HIE) after perinatal acidosis showed elevated Protein S-100 serum levels, whereas newborns without these signs had normal concentrations. S-100 might thus be a marker of central nervous system damage in newborns. Key words: Asphyxia, brain damage, neonate

Acidosis↗
PubMed2000

Repeated delayed sternal closure with stenting for right and left heart failure.

Delayed sternal closure is an established method to overcome circulatory instability, especially in pediatric cardiac surgery. We describe the management of complications in a seven-year-old boy in whom staged chest closure augmented by sternal stenting was used twice within three weeks, once for right heart and once for left heart failure.

Cardiac Output, Low↗
PubMed1999

Resection of a large right atrial hemangioma in a neonate after prenatal diagnosis.

Cardiac hemangiomas are extremely rare benign tumors. We describe the case of a right atrial hemangioma in a neonate diagnosed prenatally and successfully operated 10 days after spontaneous delivery. This unusual case illustrates the importance of prenatal diagnosis and delivery of the baby next to a pediatric center with a department of appropriately specialized cardiovascular surgery.

Female↗
PubMed1999

Preparatory surgical stent placement facilitating extracardiac vascular connections.

Native pericardium can be valuable material for the construction of extracardiac vascular connections. To avoid its scarring by adhesions and to preform future vascular connections, ringed polytetrafluoroethylene prostheses were implanted into the pericardial sac during staged operations for univentricular heart disease. At reoperation, extracardiac connections were found to be greatly facilitated by this approach.

Anastomosis, Surgical↗
PubMed1998

The role of spinal angiography in operations on the thoracic aorta: myth or reality?

BACKGROUND: The importance of preserving the artery of Adamkiewicz during replacement of the thoracoabdominal aorta is debated. We report our experience with the use of preoperative spinal angiography and modification of the surgical technique. METHODS: Between September 1993 and March 1996, 46 patients (mean age, 57 years; range, 25 to 73 years) underwent spinal angiography at our institution, 23 for an aneurysm and 23 for chronic dissection. Localization of the artery of Adamkiewicz between T-9 and L-3 was successful in 30 (65%) patients: T-9, left = 2, right = 1; T-10, left = 4; T-11, left = 10, right = 2; T-12, left = 3, right = 1; L-1, left = 1, right = 2; L-2, left = 2, right = 1; and L-3, left = 1. Thirty-one patients subsequently underwent replacement of the descending thoracic aorta and 13 underwent replacement of the thoracoabdominal aorta. Left atrial-femoral artery bypass was used in 23 patients and full extracorporeal circulation was used in 20 patients. Twelve procedures included the reimplantation of crucial intercostal/lumbar branches. RESULTS: The operative mortality rate was 6.8% (3 of 44 patients) and 1 (2.27%) patient had paraparesis. In addition to the 12 patients who underwent targeted reimplantation of the intercostal branches, evaluation of the spinal cord blood supply influenced the operative technique in 19 other patients. CONCLUSIONS: Selective angiography can demonstrate the spinal cord blood supply even in patients with complex aortic pathology. It is a helpful tool for planning extensive replacement of the thoracic and thoracoabdominal aorta.

Adult↗
PubMed1998

Fibrin sealant, aprotinin, and immune response in children undergoing operations for congenital heart disease.

OBJECTIVE: Most commercially available fibrin sealants contain aprotinin in doses of 1500 kallikrein inactivator units per milliliter. They are used in many operative disciplines. An elevated risk of hypersensitivity reactions exists at reexposure to aprotinin. Our aim was to examine the immunogenic potency of aprotinin as a fibrin sealant content. METHODS: We investigated 49 children with operatively treated congenital heart disease. All patients received aprotinin only topically as contained in fibrin sealant. Serum samples were drawn preoperatively, 1 week, 2 weeks, 6 weeks, and approximately 1 year after operation. They were analyzed for aprotinin-specific immunoglobulin G antibodies with a standard enzyme-linked immunosorbent assay and a fluorescence enzyme immunoassay for aprotinin-specific immunoglobulin E antibodies. RESULTS: At 1 week, 2 weeks, 6 weeks, and 1 year, we found prevalences of 8% (2 of 26), 8% (2 of 24), 6% (3 of 49), and 0% for aprotinin-specific Immunoglobulin E, and for aprotinin-specific immunoglobulin G 8% (2 of 26), 17% (4 of 24), 39% (19 of 49), and 12% (5 of 41). The doses of aprotinin given did not differ significantly in antibody-negative and antibody-positive patients; no significant factors could predict the immune response. CONCLUSIONS: Our findings show the existence of a subgroup of patients who had aprotinin-specific antibodies develop after topical aprotinin application. Any use of aprotinin must be carefully documented. If aprotinin use is planned in patients who previously underwent a surgical procedure, preexposure to aprotinin in any form must be sought to avoid unexpected anaphylactic reactions. The necessity itself and alternatives for aprotinin as a stabilizing agent in fibrin sealants merit consideration.

Anaphylaxis↗
PubMed1998

Combined Norwood and Rastelli procedure for repair of interrupted aortic arch with subaortic stenosis.

A neonate presented with an interrupted aortic arch type B and VSD with dysplastic aortic valve, subaortic stenosis, and aberrant right subclavian artery. We performed a direct anastomosis between the hypoplastic ascending aorta (0 3 mm), the main pulmonary artery and the descending aorta, mimicking a Norwood-type ventricular outlet. The right-ventricular outflow tract was reconstructed with a 8mm PTFE vascular graft. This combination of a modified Norwood with a Rastelli procedure facilitated establishment of a sufficiently large left-ventricular outflow tract via VSD, at the same time maintaining a biventricular system despite the coexisting anomalies.

Abnormalities, Multiple↗
PubMed1997

Extraanatomic thoracic aortic bypass grafts: indications, techniques, and results.

OBJECTIVE: Even in the age of extensive aortic replacement special circumstances may warrant the insertion of extraanatomic thoracic aortic bypass grafts. Our experience with 17 patients is analyzed. METHODS: Between 1988 and 1994, ten female and seven male patients (mean age 37.5 years, range 9-69 years) were treated for the following indications: (1) complex CoA (n = 5); (2) reoperation for CoA (n = 6); (3) extensive aortic occlusive disease (n = 4); and (4) complicated aneurysm (n = 2). Routing of the grafts was: ascending-descending aorta (8); ascending-abdominal aorta (4); left subdavian artery- descending aorta (2); descending-descending aorta (2); and descending-abdominal aorta (1). Eight procedures were reoperations. In four patients concomitant cardiac operations were performed: one aortic valve replacement, one patch plasty of the LCA, and two composite graft replacements of aortic valve and ascending aorta, one of them with CABG. RESULTS: Three early deaths occurred. two after emergency operation in thoracic aneurysm under dire conditions (one perforation, one infection), one after ascending-abdominal aortic grafting with multiple branch revascularization. The underlying pathology was relieved successfully in all 14 survivors. In the two patients with concomitant aortic valve and isthmic stenosis, critical anterior motion of the mitral valve, presumably because of the massive afterload reduction of the left ventricle, complicated the perioperative course. One patient was reoperated because of aneurysm 4 years after descending-descending aortic grafting for complex CoA with poststenotic dilatation. CONCLUSIONS: In complex aortic coarctation or hypoplasia extraanatomic bypass grafts are expedient and effective procedures, especially for reoperation. Their use in the treatment of aneurysmal lesions remains an exception.

Adolescent↗
PubMed1997

Postischemic synthesis of high energy phosphates in isolated porcine hearts during reperfusion with 11 or 25 degrees C hypothermic perfluorocarbon emulsion FC 43. A 31P magnetic resonance spectroscopy study.

OBJECTIVE: One aim of coronary reperfusion after myocardial ischemia is to restore the myocardial content of high energy phosphates. The superiority of the artificial oxygen carrier perfluorocarbon emulsion FC43 over blood solution is known, therefore, in this paper we examined the temperature-dependence of this substance. METHOD: The changes of the high energy phosphates phosphocreatine (PCr) and inorganic phosphate (Pi) were documented in 29 isolated pig hearts, employing a 4.7 Tesla magnetic-resonance-spectroscope (MRS). After 15 min warm ischemia, reperfusion with warm blood and a cardioplegic ischemia period of 45 min, these hearts were reperfused with either 11 or 25 degrees C hypothermic oxygenated perfluorocarbon emulsion FC43, both under continuous spectroscopy. MRS is able to directly measure PCr as well as Pi. Their relation expresses the state of myocardial energy stores. RESULTS: Reperfusion with 11 degrees C hypothermic FC43 (n = 14) caused an increase of the relation PCr to Pi by a factor of 9, compared to an increase by a factor of 4 with 25 degrees C emulsion (n = 15) (P < 0.05). During 80 min of reperfusion with 11 degrees C cold FC43 emulsion the average flow rate was 90 +/- 12 and 96 +/- 11 ml/min during reperfusion with 25 degrees C hypothermic FC43 emulsion. Both rates fell only slightly in the course of time. CONCLUSION: We conclude that reperfusion with 11 degrees C hypothermic oxygenated FC43 in isolated ischemic porcine hearts leads to a clear increase of the index PCr/Pi compared with reperfusion at 25 degrees C. The correlation between the synthesis of myocardial high energy phosphates with postcardioplegic ventricular function is questionable. If further studies will show an improvement of myocardial function after perfusion with hypothermic oxygenated perfluorocarbon emulsion FC43, this solution may find clinical application in the storage of explanted human hearts for transplantation, during transportation to the recipient.

Animals↗