Search PubMed⌕ Search

Biomedical subjects

D Schmidt

Publications and source records attributed to D Schmidt.

At least 361 records · Page 20Linked to original sources
PubMed1992

[The pathology of soft tissue sarcomas].

Soft tissue sarcomas are rare and can cause considerable difficulty in diagnosis and differential diagnosis as well as in estimation of the prognosis. These problems are due in part to the wide histological diversity, which is a consequence of intratumoral heterogeneity. The best known example of a very heterogeneous soft tissue tumor is malignant fibrous histiocytoma (MFH). Regular application of ancillary techniques, including electron microscopy and immunohistochemistry, has made it possible to reduce the number of unclassified cases from more than 10% to about 5%. Further progress in this direction is to be expected from cytogenetic studies, since for some of the tumor types characteristic chromosomal abnormalities have been established. Prognosis has been related to the grade of malignancy, but recent studies show that in many soft tissue sarcomas it will also be possible to correlate prognosis with DNA ploidy. By contrast, overexpression of the multidrug resistance gene mdr-1 does not seem to play an essential role in soft tissue sarcomas.

Diagnosis, Differential↗
PubMed1992

[Rhabdomyoma of the mouth floor--a case report].

We report a rare case of an adult rhabdomyoma of the floor of the mouth in a 52-year-old woman. To date only 25 cases of such tumors have been described in the oral cavity. In spite of its large size (approximately 10 x 8 x 6 cm), the tumor could be completely removed. Up to now, 20 months after the removal of tumor, no recurrences, have occurred.

Biomarkers, Tumor↗
PubMed1992

Automatic implantable cardioverter-defibrillator: early experience at Wilford Hall USAF Medical Center.

Fifteen patients with malignant ventricular arrhythmias were treated with the automatic implantable cardioverter-defibrillator (AICD) over a 22-month period. The cause of the arrhythmia was coronary artery disease in 13 of the patients (87%), sarcoid cardiomyopathy in one (7%), and a primary electrical abnormality in one (7%). The mean ejection fraction was 29%, with a range of 15% to 70%. Fourteen of the patients had inducible ventricular tachycardia using program stimulation. Defibrillating and rate-sensing leads were inserted through a lateral thoracotomy in 13 patients and through a median sternotomy in two patients in conjunction with other cardiac procedures. The generators were positioned in a subcutaneous pocket beneath the left costal cartilage. There was one early and one late death, both due to congestive heart failure. Neither was related to a ventricular tachyarrhythmia, and in each patient the AICD was functioning properly at the time of death. The mean follow-up period was 11.5 months, with five patients receiving a total of 17 shocks. We conclude that the AICD is a highly effective, low-risk treatment for malignant ventricular tachyarrhythmias.

Adult↗
PubMed1991

Malignant peripheral neuroectodermal tumor and its necessary distinction from Ewing's sarcoma. A report from the Kiel Pediatric Tumor Registry.

A new classification scheme is proposed for the differential diagnosis of Ewing's sarcoma and malignant peripheral neuroectodermal tumor (MPNT) based on conventional light microscopic and immunohistochemical findings. The presence of Homer-Wright rosettes and/or the expression of at least two neural markers is diagnostic of MPNT Ewing's sarcoma. Ewing's sarcoma was diagnosed in cases lacking Homer-Wright rosettes and expressing no neural marker or only one in immunohistochemistry. Using this "new" approach considerable differences were found between both tumor types. Although most MPNT were located in the thoracopulmonary region, Ewing's sarcoma was located predominantly in the pelvis and extremities. The mean age of MPNT patients was greater than that of Ewing's sarcoma patients. Most importantly, however, was a statistically significant difference in prognosis: disease-free survival in Ewing's sarcoma patients at 7.5 years follow-up was 60% compared with 45% MPNT patients (P = 0.026). The detection of HNK-1 in MPNT indicated a more aggressive biologic behavior, and the expression of protein S-100 appeared to be correlated with a more favorable clinical course.

Adolescent↗
PubMed1991

Synovial sarcoma in children and adolescents. A report from the Kiel Pediatric Tumor Registry.

Of 49 cases of synovial sarcoma, which represent 5.8% of all soft tissue sarcomas with confirmed diagnosis in the files of the Kiel Pediatric Tumor Registry (Kiel, Germany), 35 occurred in patients up to the age of 18 years. The lower extremities were the most common. The 35 cases included 21 biphasic and 14 monophasic fibrous synovial sarcomas. The different cell types constituting synovial sarcoma could be demonstrated by conventional light microscopic study, but more readily so by immunohistochemical study, particularly when antibodies against cytoskeletal components were applied. Aberrant antigen expression was noticed for the neural markers, protein S-100, and neuron-specific enolase. Moreover, four tumors were positive for Ki M7. Collagen type IV was found in all tumors tested. For the 20 patients enrolled in the Cooperative Soft Tissue Sarcoma Study of the German Society of Pediatric Oncology (GPO) the survival rate at 7 years is 63%. When five patients with initial recurrence are excluded, the survival rate is 72%. It is concluded that immunohistochemical study is useful in the diagnosis and differential diagnosis of synovial sarcomas despite certain limitations. Multimodality treatment approach has improved the overall prognosis. There is no relationship between histologic subtype and prognosis according to the classification scheme employed in this study.

Adolescent↗
PubMed1991

Differentiation of hematuria by quantitative determination of urinary marker proteins.

Hematuria caused by prerenal, glomerular, postglomerular, and postrenal causes is usually differentiated by a number of noninvasive and invasive diagnostic procedures. In the present study we have applied a new analytical strategy based on observations that the various forms of hematuria can be classified by their typical protein pattern. When analyzed by quantitative turbidimetric assays, urines from postrenal hematurias contained high-molecular-weight proteins (alpha 2-macroglobulin and IgG) in proportions found in plasma. Relating excretion rates (mg/mg) of these proteins to those of albumin, ratios for alpha 2-macroglobulin/albumin and IgG/albumin were 2.0-31 x 10(-2) and 20.0-180 x 10(-2), respectively. In contrast, glomerular hematurias exhibited ratios of 0.01-2.0 x 10(-2) (alpha 2-macroglobulin/albumin) and 2.0-20 x 10(-2) (IgG/albumin). Additional determination of alpha 1-microglobulin allowed us to differentiate postglomerular hematurias caused by interstitial nephropathies from glomerular and postrenal diseases. Critical evaluation of 93 cases diagnosed by independent clinical examination including histology, sonography, and cystoscopy revealed that the criteria derived from protein measurements resulted in correct classification when urine albumin exceeds 100 mg/l. This noninvasive procedure is expected to be of considerable help in the primary care of patients with unexplained hematuria.

Adolescent↗
PubMed1991

Renal cell carcinoma in children: histology, immunohistochemistry, and follow-up of 10 cases.

Ten renal cell carcinomas in children under 15 years were investigated. The average age was 122.5 months and the girls predominated in our cases (7 girls, 3 boys). By using the classification of Thoenes et al., Pathol Res Pract 181: 125-143, 1986 a predominance of clear cell-eosinophilic tumor cell type and of the tubulopapillary growth pattern was found. Immunohistochemistry revealed a heterogeneity of cytokeratin expression. By using the monoclonal antibodies Cam 5.2 and KL 1, cytokeratins were found in 7 cases each. The other 4 cytokeratin antibodies used were less sensitive. The expression of cytokeratin 13 in 3 cases suggested a more complex histogenesis than assumed. Vimentin was found in 3 tumors, but an association to a higher grade (G) of malignancy was not found in these cases. One tumor expressed the Tamm-Horsfall-protein, which is predominantly found in the distal tubule of the normal kidney. In summary the results of immunohistochemistry characterized the great heterogeneity of these tumors. Follow-up information was available in 9 cases. All patients with G I- and G II-tumors were free of disease after an average time of 39.6 months (mean 27 months). Two of the 3 cases with G III-tumors died after 9 and 15 months, despite additional chemo- or radiotherapy. Therefore tumors of grade I and II of the Thoenes classification seem to have a good prognosis.

Adenocarcinoma↗
PubMed1991

Infantile desmoid-type fibromatosis. Morphological features correlate with biological behaviour.

It is generally agreed that the biological behaviour of infantile desmoid-type fibromatosis is unpredictable in terms of the likelihood of local recurrence. We evaluated the prognostic importance of the number of slit-like blood vessels with a mean diameter of less than 20 microns and of the quantity of undifferentiated mesenchymal cells. In addition, we studied the immunophenotypic characteristics of the proliferating cells and their nucleolar organizer region (AgNOR) numbers and distribution. Statistical analysis showed that the tendency to recur locally was correlated with larger numbers of slit-like blood vessels and undifferentiated mesenchymal cells. The proliferating cells were identified by immunohistochemistry as myofibroblasts. No correlation was found between AgNOR numbers and clinical course of the disease. We conclude that histological features easily evaluated by conventional light microscopy provide useful information on the possible course of infantile desmoid-type fibromatosis.

Actins↗
PubMed1991

[Therapy of bleeding esophageal varices in West Germany--results of a survey].

An inquiry concerning bleeding of esophageal varices included 1076 surgical and medical departments in the Federal Republic of Germany (West). Prevailing forms of treatment are acute sclerotherapy or esophageal balloon tamponade followed by long-term sclerotherapy. In case of medically uncontrollable bleeding oesophagogastric devascularization procedures are preferred to portacaval shunt. Beta-blockers are applied in medical departments for the prophylaxis of recurrence. Only after several rebleedings, despite of sclerotherapy, approx. half of the departments consider an elective shunt. The distal splenorenal shunt described by Warren and portacaval anastomosis clearly prevail over all other shunts.

Combined Modality Therapy↗
PubMed1991

The effect of gestational age on the detection rate of Down's syndrome by maternal serum alpha-fetoprotein screening.

Low levels of maternal serum alpha-fetoprotein are currently being used to screen for Down's syndrome in midpregnancy. Because of the possibility that gestational age may affect the detection rate of Down's syndrome, we analyzed maternal serum AFP levels and gestational age in 51 Down's syndrome pregnancies that had been confirmed by amniocentesis or at birth, and we compared these pregnancies with 3239 screened singleton pregnancies with known normal outcomes. The highest yield of a low risk for Down's syndrome associated with maternal serum alpha-fetoprotein occurred at 16.5 to 17.5 weeks' gestation. Our data suggest that maternal serum alpha-fetoprotein screening for Down's syndrome should be done between 16 and 18 weeks' gestation, which is the gestational age currently recommended for neural tube defect screening.

Case-Control Studies↗
PubMed1991

Pericardial mass mimicking constrictive pericarditis.

Persistent pericardial hematoma due to blunt chest trauma is extremely rare. We report a case of constricted myocardium resulting from a large, partially organized hematoma in the right cardiophrenic angle. The hematoma was assumed to be caused by an occupational accident 17 years before diagnosis. Constriction could only be controlled by complete removal of the fibrous posterior capsule of the hematoma, which covered the epicardium of the right heart.

Aged↗
PubMed1991

Pulmonary myofibroblastic nodules with "amianthoid features".

Two consecutive publications appeared 1989 in the same number of a medical journal, which reported peculiar spindle-cell tumors with dense collagen or hyaline nodules, exclusively in inguinal lymph nodes of adults. The first series of 22 cases bore the title "Palisaded myofibroblastoma, a benign mesenchymal tumor of lymph node", the second with 6 identical cases "Intranodal hemorrhagic spindle-cell tumor with "amianthoid" fibers". The following case report deals with a similar tumorous lesion, with multiple small pulmonary nodules, without recognizable lymph node constituents.

Biopsy↗
PubMed1991

[Prepontine artifacts due to cerebrospinal fluid pulsation in the T-2 weighted coronal MRT picture. Clinical significance, frequency, technique for artifact suppression].

Coronal T2-weighted MRI is the most sensitive imaging modality to detect temporal lobe pathology. However, prepontine artifacts resulting from pulsation of cerebrospinal fluid occasionally simulate temporal lobe lesion. To characterize this artifact we studied 30 patients without temporal lobe pathology in conventional T2-weighted spin-echo technique (0.5 T, SE 1600/70, coronal, horizontal phase encoding). Visual analysis revealed high-intensity artifacts simulating a lesion in five of 30 cases. The present study shows that prepontine artifacts due to pulsation of cerebrospinal fluid are quite frequent (17%) and that these artifacts may result in misinterpretation in the evaluation of temporal lobe epilepsy. By a repeat examination in identical methodology while using vertical phase encoding, all artifacts could be identified and an artifact-free representation of the temporal lobes was achieved.

Adult↗
PubMed1991

[The demonstration of calcifications in magnetic resonance tomography (MRT). The effect of different parameters on the MRT imaging of cerebral calcifications].

The effect of various factors on the demonstration of calcified lesions was studied in 131 areas of calcification which had been demonstrated by CT. By means of MRI (SE 400/30 or GE315/14, 90 degrees and SE 1600/30 + 70; 0.5T) 117 of the 131 calcified lesions (89%) produced a signal difference. Of these 117 lesions, 80 (61%) were recognised as calcification by MRI. Large areas of calcification (more than 5 mm) and high density calcification (more than 100 Hu) were recognised significantly more often than small or low density calcifications. T2-weighted images demonstrated calcification more often than other sequences. With conventional pulse sequences, calcified lesions were frequently recognised as abnormalities on MRI, but their recognition as calcified lesions is unreliable.

Brain↗