PubMed Health⌕ Search

Biomedical subjects

R M Bohle

Publications and source records attributed to R M Bohle.

At least 55 records · Page 3Linked to original sources
PubMed1998

[Heart transplantation in infancy: experiences at the Giessen Pediatric Heart Center].

From June 1988 to December 1996 heart transplantations were performed in 36 newborns and infants below one year of age. Diagnosis were hypoplastic left heart syndrome (n = 26), endocardial fibroelastosis (n = 4), cardiomyopathy (n = 3), and other complex congenital heart defects (n = 3). Mean waiting time for transplantation was 52 days, the mean donor-recipient bodyweight ratio was 1.8. Seven patients (19%) died after transplantation mainly within the first month after transplantation. The cumulative probability of survival is 79% in all patients. The influence of increasing experience is indicated when patients transplanted from 1988-1993 (n = 15) are compared with transplants from 1994-1996 (n = 21). The overall survival in the first group was 50%, whereas patients transplanted from 1994 showed a probability of survival of 92%. The 1-year survival rate in the later group was 100%. In 20 patients a total of 31 rejection episodes were observed. 2 infants died due to rejection. 71% of all rejections occurred during the first month after transplantation. Renal function was slightly impaired one year after transplantation in all patients without tendency for deterioration in the sequel. The somatic development is normal in nearly all infants and the quality of life is excellent. All infants live at home without any restrictions. Two patients, however, suffer from a neurologic deficit. Until now there is no evidence of coronary vascular disease or malignancy. Heart transplantation is in our opinion a reconsiderable alternative in the treatment of complex cardiac disease and cardiomyopathy in infants.

Cause of Death↗
PubMed1998

Histological and ultrastructural study of corneal tunnel incisions using diamond and steel keratomes.

PURPOSE: To study the morphology of corneal tunnel incisions using diamond and steel keratomes. SETTING: Department of Ophthalmology, University of Giessen, Germany. METHODS: Corneal tunnel incisions were performed in six human cadaver eyes using three types of diamond keratomes and a steel keratome. The incision profile and morphology were evaluated and compared using light and scanning electron microscopy. RESULTS: The steel keratome caused more disruption of corneal stromal tissue, while the diamond keratomes produced a more regular, smoother incision. The dissecting incision resulted in a smoother surface of cut stromal tissue than the stab incision. CONCLUSIONS: The high quality of corneal tunnel incisions produced with diamond keratomes is the result of their exceptional sharpness, which may have a beneficial effect on wound healing.

Cadaver↗
PubMed1998

Clinical experience with heart transplantation in infants.

OBJECTIVE: Orthotopic heart transplantation has become an accepted therapeutic concept for adult patients with endstage heart disease. In newborns and infants this procedure is still a matter of discussion because of unknown long-term results and the lack of donor organs. METHODS: Since March 1988 we have performed 40 orthotopic heart transplantation in 39 infants who were from 1 to 280 days of age. Indications for transplantation included hypoplastic left-heart syndrome (n = 28), dilative cardiomyopathy (n = 4), endocardial fibroelastosis (n = 4) and other complex structural anomalies (n = 3). The mean waiting period for transplantation was 53 days. A donor-recipient weight ratio up to 4.0 was accepted. Profound hypothermic circulatory arrest was used for graft implantation in all those patients who required extensive aortic arch reconstruction (71%). The initial immunomodulation was based on Cyclosporine, Azathioprine and Prednisolone. Patients who underwent transplantation during the first 6 weeks of life received a chronic single-drug therapy with Cyclosporine after 1 year. RESULTS: There were six peri-operative deaths caused by drug-resistant right-heart failure in three cases, humoral rejection (n = 1), CMV infection (n = 1) and multi organ failure (n = 1). One infant died late, due to rejection. The actuarial survival rate for the entire group is now 82%. There is a remarkable influence of increasing experience. Whereas six of 15 infants who had heart transplantation between 1988 and 1993 died early post-operatively (survival rate: 60%), only one late death occurred among 24 recipients in the period from 1994 to April 1997 (survival rate: 96%). Episodes of rejection occurred once or several times in about half of the patients in this series (48%). All surviving children are living at home in excellent condition. CONCLUSIONS: Heart transplantation during early infancy is a rational and durable therapy for heart diseases with irreversible myocardial failure or severe structural anomalies. The intermediate-term results have been encouraging in many centers, but more data must be accumulated to determine the sequelae of chronic immunosuppression. The lack of donor organs remains one of the major problems in pediatric heart transplantation.

Body Height↗
PubMed1998

Real-time quantitative RT-PCR after laser-assisted cell picking.

The present study describes a technique for quantitation of mRNA in a few isotypic cells obtained from an intact organ structure by combining laser-assisted cell picking and real-time PCR. The microscopically controlled lasering of selected cells in stained tissue sections was applied to lung alveolar macrophages, which are unique in that they can alternatively be gathered as a pure cell population from intact lungs by bronchoalveolar lavage as a reference technique. TNF-alpha was chosen as the transcriptionally inducible target gene to be quantified in alveolar macrophages of control rat lung, as well as low- and high-challenge lungs stimulated by endotoxin and IFN-gamma nebulization. Online fluorescence detection for quantitation of the number of amplified copies was based on 5' nuclease activity of Taq polymerase cleaving a sequence-specific dual-labeled fluorogenic hybridization probe. A pseudogene-free sequence of PBGD served as an internal calibrator for comparative quantitation of target. A quick procedure and minimized loss of template were achieved by avoiding RNA extraction, DNase digestion and nested-PCR. Using this approach, we demonstrated dose-dependent manifold upregulation of the ratio of TNF-alpha mRNA copies per one copy of PBGD mRNA in alveolar macrophages of the challenged lungs. The quantitative data obtained from laser-picked alveolar macrophages were well matched with those of lavaged alveolar macrophages carried out in parallel. We suggest that this new combination of laser-assisted cell picking and real-time PCR has great promise for quantifying mRNA expression in a few single cells or oligocellular clusters in intact organs, allowing assessment of transcriptional regulation in defined cell populations.

Animals↗
PubMed1998

[Inverted transitional cell papilloma of the conjunctiva with peripheral carcinomatous transformation].

BACKGROUND: Inverted papilloma is a benign epithelial neoplasm of mucous membrane, usually arising in the nose and paranasal sinuses, much rarer of the conjunctiva. Histologically ribbons or bulbous expansions of the epithelium invaginate into the underlying connective tissue. In opposite to their sinonasal counterparts the few described papillomas of the conjunctiva til now have not shown any signs of malignant transformation or recurrence after local excision. PATIENT: A 96-year old woman presented with a solid tumour on the nasal bulbar conjunctiva of her right eye, which had persisted at least over 6 months. Ocular examination showed a 25 x 15 x 15 mm reddish tumour with papillary surface. Histologic features of the excised specimen were consistent with inverted papilloma, but here were significant carcinomatous foci in peripheral areas. Four months later there was a tumour recurrence on the bulbar and tarsal conjunctiva. CONCLUSIONS: Inverted papilloma of the conjunctiva is an unusual diagnosis and to date there is no previous report of malignant transformation. With only seven cases described so far the biologic behavior remains uncertain, but it seems to be more aggressive than assumed so far. Complete excision is the treatment of choice, but patients should be carefully observed and adjuvant therapy could be necessary to ensure tumour control.

Aged↗
PubMed1998

Evaluation of ZP2 domains of functional importance with antisera against synthetic ZP2 peptides.

The mouse zona pellucida protein ZP2 plays an important role in the process of fertilization by mediating secondary sperm binding to mammalian oocytes. ZP2 primary structures are highly conserved as revealed by cDNA cloning. The aim of the study was to identify ZP2 domains of functional relevance. Antisera were raised against synthetic peptides that are either conserved in the structure of ZP2 from different mammalian species (AS ZP2-20) or present in the human ZP2 but not in the mouse ZP2 amino acid sequence (AS ZP2-26). Antibody binding to zona pellucida proteins was assessed by assaying the antisera with human hemizonae. Using human zonae pellucidae, we demonstrated that anti-ZP2 common antibodies and anti-ZP2 human peptide antibodies react with human zona pellucida antigens. For the first time, ZP2 domains of functional relevance for human sperm-oocyte interaction could be identified applying the competitive hemizona assay. Antiserum AS ZP2-20 significantly inhibited binding of spermatozoa to test hemizonae, whereas treatment of hemizonae with AS ZP2-26 did not influence sperm-oocyte interaction. These results show that antibodies against synthetic ZP2 peptides react with ZP2 protein and that AS ZP2-20 identifies a linear ZP2 epitope that is of possible functional importance for sperm-oocyte interaction.

Amino Acid Sequence↗
PubMed1998

[Bone matrix production in osteosarcoma].

Osteosarcomas produce an extracellular matrix (ECM), called tumor osteoid, which is also the microscopic hallmark of these tumors. It can be difficult to differentiate tumor osteoid from other formations of ECM in intra-and extraskeletal soft tissue tumors, so that problems in differential diagnosis arise. Conventional special stainings provide a means to increase the reliability of the differential diagnosis, but do not identify the type of tumor conclusively as they only reflect physiochemical features and do not identify the molecular components of the matrix. The key to the solution of this problem is the immunohistochemical use of antibodies against bone matrix components. Matrix-immunohistochemistry using polyclonal and monoclonal antibodies against COL-I-C-peptide, Osteopontin, Osteonectin, Osteocalcin, and Decorin have proved to be a useful tool for the differentiation of osteoid in a series of 20 osteosarcomas with different variants of osteoid formation. For the detection of undifferentiated tumors, however, this method has not proved useful, since the cytoplasmatic immunoreactivity is variable. Molecular methods appear to be a more promising tool. Since the expression of Osteocalcin is known to be the last step of the osteoblastic differentiation, we have established a method to detect osteocalcin mRNA by RT-PCR. First studies of our group on the identification of the osteoblastic differentiation at the molecular level have revealed that Osteocalcin mRNA can be detected both in osteosarcoma cells and in non-skeletal tumor cell lines. In order to provide a reliable means of molecular tumor characterisation, thorough comparative studies on fresh and paraffin material of larger tumor series are in progress.

Bone Matrix↗
PubMed1998

[CD 143 expression in benign and malignant vascular tumors].

The somatic form of CD 143 (angiotensin-I-converting enzyme) has been detected in many endothelial cells of the human body. Recently, we could identify local CD 143 overexpression in various pathological conditions e.g. in capillary endothelial proliferations at the border of myocardial infarctions and in coronary atherosclerotic plaques. Using monoclonal antibodies against CD 143, CD 31 and CD 34 we evaluated, whether CD 143 can serve as a marker of endothelial differentiation in vascular/perivascular tumors. 39 benign and malignant tumors, formalin-fixed, paraffin-embedded were investigated by APAAP immunohistochemistry using epitope retrieval techniques. Expression patterns were separately qualitatively and semiquantitatively analysed. Positive detection of epitopes was registered if more than 10% of the tumor cells were stained. CD 143 was detected in the majority of benign and malignant vascular tumors. All benign and malignant haemangioperizytomas were CD 143 negative. None of the markers detected all haemangioendotheliomas or all angiosarcomas, but the combination of CD 143 and CD 31 turned out to be positive in all haemangioendotheliomas and angiosarcomas. We conclude that most of the benign and malignant endothelial tumors express CD 143. The best discrimination of intermediate grade and malignant endothelial tumors can be achieved by analysis of the CD 143 and CD 31 co-expression.

Antigens, CD34↗
PubMed1998

[Significance of differential nuclear expression of Ki-67 in adult soft tissue sarcomas].

As many other nuclear markers, e.g. steroid receptors, Ki-67 epitopes are differentially expressed in tumour cell nuclei. It is unclear whether this phenomenon represents tumour cell heterogeneity, different stages of the cell-cycle or a biological phenomenon with prognostic impact. We analysed 104 primary adult soft tissue sarcomas (ASTS), formalin-fixed, paraffin-embedded, by APAAP and LSAB immunohistochemistry, epitope retrieval technique and 2 anti-Ki-67 antibodies (MIB-1 and Ki-S-5). Expression was evaluated by 4 indexes/1000 tumour cells: a) A-index: sum of all (weak, moderate and strong stained) Ki-67-nuclei, b) the weighed R-index: sum of all strong stained Ki-67+ nuclei x3, moderate stained nuclei x2 and weak stained nuclei x1, c) ID1-index: sum of all strong stained Ki-67+ nuclei, and d) ID2-index: sum of all strong and moderate stained Ki-67+ nuclei. Prognostic impact was analysed by Kaplan-Meier and logrank statistics with respect to overall survival. Quantitative Ki-67 expression did not vary significantly if determined by MIB-1 or Ki-S-5. The A-index turned out to be the strongest prognostic parameter within the whole group of ASTS as well as within each single sarcoma type investigated. Significant (p < 0.05) correlations between A-index and overall survival existed in LMS, LPS, MFH, SS, while a trend to significance (p = 0.06) was observed in MPNST. Quantitative evaluation of all three differential expression levels is necessary to obtain the most comprehensive prognostic informations of proliferation markers in ASTS.

Adult↗
PubMed1998

Coarctation of the thoraco-abdominal aorta: operative treatment with a cryopreserved arterial homograft in a seven-year-old boy.

Compared to coarctation in the proximal descending aorta near the insertion of the ligamentum arteriosum, coarctation in the aortic arch, the lower descending or the abdominal aorta is a relatively rare disease. Operative treatment of abdominal coarctation is more complicated if there are concomitant stenoses of visceral or renal arteries. In young patients, surgical procedure and outcome is additionally determined by caliber and compliance mismatch between still growing native vessels and arterial substitute. Our report deals with a seven-year-old male patient, who was first diagnosed as having coarctation of the aorta at five years of age due to distinct bilateral brachial hypertension. The angiogram revealed a narrowing of the aorta, approximately ten centimeters in length, from the lower descending segment down to the proximal abdominal part of the aorta. The origin of the superior mesenteric artery and both renal arteries were not involved in the pathological process. Arterial reconstruction was carried out by anastomosis of cryopreserved arterial homograft with the thoracic aorta and with the abdominal aorta distal to the origin of the renal arteries. The postoperative course was uneventful, duplex sonography revealed no pressure gradient between the thoracic and abdominal aorta and brachial blood pressure was within normal ranges.

Aorta↗
PubMed1998

[Expression of cell adhesion molecules in the extravillous trophoblast in placentas of preterm pregnancies and in placentas at term].

Invasion of the human trophoblast is regulated by cell adhesion molecules (CAM) such as integrins and members of the immunoglobulin superfamily, which also play an important role in a number of immunological reactions. Abnormal trophoblast invasion of the uterus and its arterial system has been related to preterm delivery. We examined the differences of CAM expression in the extravillous trophoblast of preterm (n = 18) and term pregnancies (n = 21). Placenta and decidua frozen sections were examined by double-staining immunohistochemistry using antibodies against the immunoglobulin superfamily (ICAM-1, ICAM-2, ICAM-3, VCAM-1), integrins (alpha 2 beta 1, alpha 3 beta 1, alpha 4 beta 1, alpha 5 beta 1, alpha 6 beta 1) and cytokeratin. The percentage of immunopositive extravillous trophoblast cells and the intensity of immunoreactivity for the mentioned CAM antibodies was assessed. The expression of alpha 3 beta 1, alpha 5 beta 1 and VCAM-1 (p < 0.05) in the extravillous trophoblast of preterm placentas was lower than in normal placentas, whereas the expression of alpha 6 beta 1 in the extravillous trophoblast of preterm placentas was higher than at term (p < 0.05). No differences were observed for alpha 2 beta 1, alpha 4 beta 1, ICAM-1, ICAM-2 and ICAM-3. Our results show that there is a different expression of cell adhesion molecules in the extravillous trophoblast of placentas in preterm delivery. These differences in CAM might be associated with abnormal immunological and cell-cell interactions between mother and developing fetus and thus cause preterm labor and delivery.

Antibodies, Monoclonal↗
PubMed1997

The expression of angiotensin-I converting enzyme in human atherosclerotic plaques is not related to the deletion/insertion polymorphism but to the risk of restenosis after coronary interventions.

Plasma and tissue concentrations of the angiotensin-I converting enzyme (ACE) have been shown to be associated with the ACE insertion/deletion (I/D) polymorphism. The purpose of this study was to examine the relation of ACE levels in atherosclerotic plaques to the ACE I/D polymorphism and to restenosis after balloon angioplasty and directional atherectomy (DCA). The study included 104 patients who underwent DCA and received angiographic follow-up at 12 to 18 months. The amount of ACE protein in various morphologically defined plaque components (fibrous, atheromatous, and complicated lesions) of the atherectomy specimens was determined by qualitative and semiquantitative immunohistochemistry. ACE levels were related to the ACE genotype, to plaque morphology and to the risk of restenosis. Sequential staining revealed that pathologic ACE overexpression of the atherosclerotic lesions occurred in intimal smooth muscle cells, fibrocytes/fibroblasts and macrophage/foam cells. The ACE content of the whole plaques and of the single plaque components was not associated with the I/D polymorphism, but with restenosis after coronary interventions. In addition, ACE levels in the atherosclerotic lesions correlated with the severity of vessel wall damage. The ACE phenotype might serve as an indicator for the risk of restenosis after coronary interventions.

Angioplasty, Balloon, Coronary↗
PubMed1997

Comparison of ultrasonic and histopathological features of carotid artery stenosis.

Besides the degree of carotid artery stenosis, the composition of the plaque may help to predict the thromboembolic risk. Low echogenicity on ultrasound and hemorrhage into the atheroma demonstrated histopathologically have been shown to be associated with a higher risk of embolism. Twenty-nine consecutive patients with carotid artery stenosis and scheduled for carotid endarterectomy were investigated preoperatively by B-mode ultrasound. Post-operatively the endarterectomy specimens were examined histopathologically. Neither atheroma with hemorrhage nor atheroma without hemorrhage were significantly associated with echolucent ultrasound presentation. Out of the 10 lesions echolucent and homogeneous on ultrasound, six corresponded to atheroma with hemorrhage, two corresponded to atheroma with hemorrhage plus thrombus, two corresponded to fibrous plaque plus thrombus, and one corresponded to pure thrombus. Out of the 4 lesions heterogeneous and predominantly echolucent, one corresponded to atheroma without hemorrhage plus thrombus, one corresponded to atheroma with hemorrhage, one corresponded to atheroma with hemorrhage plus thrombus, one corresponded to atheroma with hemorrhage plus fibrous plaque. Seven out of the 18 atheromas with hemorrhage did not present as purely or predominantly echolucent lesions, six of them were even homogeneously echogenic. Plaque surface could not reliably be predicted by ultrasound. In our study, there was no significant correlation between ultrasound and histology of the lesion.

Aged↗
PubMed1997

Time delay of cell death by Na+/H+-exchange inhibition in regionally ischemic, reperfused porcine hearts.

Studies in different preparations have suggested that Na+/H+ exchange is one mechanism causally involved in cell death in myocardial ischemia and reperfusion. The time delay of cell death by pretreatment with the Na+/H+-exchange inhibitor HOE642, cariporide (4-isopropyl-3-methylsulphonylbenzoyl-guanidine methanesulphonate), was investigated in regionally ischemic, reperfused porcine hearts. HOE642 (1 mg/kg) was injected intravenously in 14 thoracotomized pigs 10 min before occlusion of the left anterior descending coronary artery (45 min of ischemia, six pigs; 70 min of ischemia, six pigs; 90 min of ischemia, two pigs). Ischemia was followed by 24 h of reperfusion. Six animals (45 min of ischemia) served as controls. Infarct size was determined as a ratio of infarcted (tetrazolium stain, histology) to ischemic myocardium (dye technique), and regional myocardial function was assessed by sonomicrometry. HOE642 did not affect global hemodynamic parameters. In the pretreated group with 45 min of ischemia, HOE642 significantly decreased histochemical infarct size from 51.2 +/- 12.6% (control group) to 13.2 +/- 12% (p < 0.005) and histologic infarct size from 44.5 +/- 9% to 17.1 +/- 7% (p < 0.005). Recovery of regional systolic shortening after 24 h of reperfusion was improved from 2 +/- 6% (control group) to 12 +/- 7% (p = 0.02). In addition, myocardial contracture and increase in heart rate during early reperfusion were attenuated. When ischemia was prolonged to 70 min after pretreatment with HOE642, infarct size, recovery of systolic shortening, myocardial contracture, and increase in heart rate did not differ from those of the control group. Pretreatment with HOE642 increased the tolerance to ischemia/reperfusion by approximately 20-25 min. Inhibition of Na+/H+ exchange appears to be very promising in the clinical treatment of acute myocardial ischemia and reperfusion.

Animals↗
PubMed1997

Sequestration of the alveolar bone by invasive aspergillosis in acute myeloid leukemia.

Compared to non-invasive aspergillosis, invasive aspergillosis in the region of the mouth, jaw and face has rarely been reported. It occurs particularly often in the presence of haematological oncological illness. The case of a patient suffering from acute myeloid leukemia is described; he contracted invasive aspergillosis of the lungs and the alveolar processes in the course of chemotherapeutic treatment. All the alveolar processes in the region of the premolars and molars were demarcated and had to be removed by sequestrectomy. The therapy of invasive aspergillosis should be carried out within the framework of intensive interdisciplinary treatment. In addition to systemic and local antimycotic therapy, the debridement of necrotic hard and soft tissue was necessary.

Acute Disease↗