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Biomedical subjects

D Schmidt

Publications and source records attributed to D Schmidt.

At least 793 records · Page 44Linked to original sources
PubMedDate not supplied

Ewing's sarcoma with neuroblastoma-like features.

Four tumors with the clinical and light microscopic features of Ewing's sarcoma contained cells that possessed to varying degrees ultrastructural features suggestive of neuroblastoma. These neoplasms were considered to be Ewing's sarcoma of bone by radiologic examination and on clinical grounds, and light microscopy was consistent with the diagnosis in every case. It is suggested that the ultrastructural morphology of Ewing's sarcoma is broader than had been supposed and that the presence of dendritic processes in a small cell tumor of bone should not exclude the diagnosis of Ewing's sarcoma.

Adolescent↗
PubMedDate not supplied

Ultrastructure of human tendon sheath and synovium: implications for tumor histogenesis.

Normal human tendon sheath and synovium were studied by scanning an transmission electron microscopy. The lining cells of the two tissues appear to be identical ultrastructurally. The most superficial cells (B-cells) possess long cytoplasmic extensions that clothe the membrane surface. Intermingled with deeper B-cells are the so-called A-cells, which have similar cytoplasmic features but lack long processes and instead have many filopodia. the frequent occurrence of intermediate forms indicates that the two cells form part of a morphologic spectrum. Comparison with cells of tumors that have been ascribed to synovium or tendon sheath (synovial sarcoma, epithelioid sarcoma, clear cell sarcoma) do not reveal any close similarities that might support a histogenetic relationship.

Cell Nucleus↗
PubMedDate not supplied

Adjuvant interferon alpha therapy in renal cell carcinoma (RCC): prognostic value of DNA cytophotometry.

BACKGROUND: Adjuvant immunotherapy with interferon alpha in non-metastatic RCC is still controversial. It was the aim of the present study to investigate whether tumor ploidy can help to isolate a group of patients profitting from this treatment. MATERIALS AND METHODS: Survival data of 119 patients undergoing tumor nephrectomy because of a non-metastatic RCC were analyzed retrospectively. Ploidy was measured in every tumor by means of DNA-cytophotometry. 24 patients received an adjuvant therapy with interferon alpha for one year. Statistical evaluation was performed by the Kaplan-Meier-Method with the logrank-test. RESULTS: Ploidy could be measured in all tumors. 56 (47%) tumors showed a diploid, 63 (53%) an aneuploid DNA-distribution. Ploidy was seen to be a good prognostic factor in RCC with significantly better survival in patients with diploid than those with aneuploid tumors. The adjuvant interferon therapy provided a marginal however not significant better survival in diploid tumors. Patients with aneuploid RCC had no benefit from this treatment. CONCLUSIONS: The data show that an interferon treatment in non-metastatic RCC might improve survival in patients with the prognostic better diploid tumors. However further investigations are necessary to give a general recommendation for this therapy in this group of patients. Additional molecular tumor factors like S-phase analysis and others might also improve patient selection.

Aneuploidy↗
PubMedDate not supplied

Adjuvant immunotherapy in renal cell carcinoma--comparison of interferon alpha treatment with an untreated control.

BACKGROUND: Adjuvant immunotherapy of RCC with interferon alpha is still controversial. It was the aim of this study to investigate, whether a selected group of patients with a non-metastatic RCC can profit from this therapy. MATERIALS AND METHODS: Survival data of 125 patients with a non-metastatic RCC, who underwent a tumor-nephrectomy were analyzed retrospectively, 33 of these patients received an adjuvant immunotherapy with interferon alpha for 1 year. All tumors were classified by the TNM-system. Statistical evaluation was performed by the Kaplan-Meier-Method and the logrank-test. RESULTS: Tumor stage was seen to be an important prognostic factor in RCC with a significantly better outcome in pT2- as compared to pT3-tumors. Tumor grading was without any prognostic relevance. Adjuvant interferon alpha therapy had no effect on overall survival. After separation of the patients into pT2- and pT3/4-tumors again interferon alpha showed no significant benefit for one of the 2 groups. CONCLUSIONS: The adjuvant therapy with interferon alpha shows no significant benefit in the treatment of non-metastatic RCC. Tumor stage is no suitable factor to select a group of patients, who might profit from an interferon alpha therapy. Further studies are necessary to isolate better selection factors.

Carcinoma, Renal Cell↗
PubMedDate not supplied

Limitations of detection of bone-marrow micrometastasis in prostate carcinoma patients by CK18/PSA immunocytochemistry and PSA RT-PCR.

BACKGROUND: The aim of this study was to prove the reliability of cytokeratin 18/prostate specific antigen (CK18/PSA) immunocytochemistry to detect tumor cells in the bone marrow of patients with prostate cancer (CaP) compared with a control group without CaP. PATIENTS AND METHODS: In bone marrow aspirates of 34 patients with CaP and 11 control patients without CaP, CK18/PSA immunocytochemistry was performed and compared with PSA RT-PCR in bone marrow and blood. RESULTS: 12% of tumors showed a positive staining with PSA and and 17% with CK 18 immunocytochemistry. There was no correlation with the stage or grade of the CaP. False positive results occurred in 2 out of 6 males without CaP and in 2 out of 5 women. 35% of the samples were found to have PSA-mRNA signals in RT-PCR which were neither associated with the histological stage or grade nor the PSA staining in immunocytochemistry. CONCLUSION: False positive staining results were obtained in control patients. Detection of PSA-mRNA was not associated with immunocytochemistry. Neither immunocytochemical nor PCR results were associated with the histological stage of the CaP. Thus, detection of micrometastasis using immunocytochemical methods has to be interpreted with caution and cannot be recommended as a clinical staging procedure.

Adenocarcinoma↗
PubMedDate not supplied

Prevention of serious ophthalmic and cerebral complications in temporal arteritis?

PATIENTS: Five patients (mean age 81.6 years) developed bilateral blindness and 3 additional patients suffered cerebral strokes (mean age 58 years) due to temporal arteritis. Bilateral blindness and strokes occurred despite corticosteroid treatment. RESULTS: In all patients with temporal arteritis, the diagnosis was made too late. Patients with bilateral blindness were referred to the Eye Hospital when one eye had already become blind. The delay between the first symptoms and blindness in one eye was (average) 7 weeks. The interval between blindness of the first and second eyes was (average) 5 days in 3 patients, and simultaneous blindness in both eyes occurred in 2 patients. The other eye also became blind despite mega-doses of prednisone in 3 patients. Three additional patients already showed neurological signs and symptoms at the beginning of the temporal headache. All 3 patients developed strokes after some weeks or months. The wrong diagnosis was made in the first examination(s) by the physician with patients having prodromal signs or symptoms, but who also showed signs of other vascular diseases (diabetes mellitus, hypertension or occlusion of the internal carotid artery) which masked the inflammatory disease of temporal arteritis. CONCLUSIONS: Early diagnosis is essential to prevent severe complications. In patients with a cerebral stroke the early neurological deficits are warning signs which means that one must observe the patient regularly at short intervals. After the diagnosis has been settled, treatment of the patients for several months with a high dosage of corticosteroids is mandatory.

Adrenal Cortex Hormones↗
PubMedDate not supplied

Semiautomated and simultaneous analysis of the interleukin-10 gene microsatellites IL-10G and IL-10R by fluorescence-based polymerase chain reaction reveals significant differences in allele distributions between Caucasians (Germany) and Africans (Gabon).

Interleukin-10 (IL-10) is an important immunoregulatory cytokine influencing many aspects of the adaptive and inflammatory immune response. Two dinucleotide repeats have been identified in the 5'-UTR of IL-10 and shown to be useful genetic markers in several diseases. A simple, two-colour fluorescence assay was developed for determination of microsatellite fragment length by an automatic sequencer. Using this method polymorphisms at the IL-10G and IL-10R loci of the 5' flanking region of the IL-10 gene can be identified simultaneously. A unified standard nomenclature was applied to the known IL-10G and IL-10R microsatellites. The multiplex PCR approach was used to compare the allele frequencies in two independent donor groups from Germany (Caucasian), comprising 112 and 106 cases, respectively, and one group from Gabon (African) including 91 donors. Significant differences in the allele distribution were found. Both Caucasian populations tested showed no significant differences in their allele and genotype distribution. Whereas in Africans, allele IL-10G25 is rare at 3% compared to 21% in Caucasian, alleles IL-10G22 and G23 are more prevalent in Africans than in Caucasians (22% versus 10% and 26% versus 7%, respectively). Within the IL-10R locus, the allele R13 was observed at 88% in the African group compared to 69% in Caucasians. These data may help immunogenetic studies in diseases, where IL-10 is thought to be deregulated.

Alleles↗
PubMedDate not supplied

Removal of amalgam, glass-ionomer cement and compomer restorations: changes in cavity dimensions and duration of the procedure.

This study investigated changes in the dimensions of Class II cavities following the removal of amalgam, glass ionomer and compomer restorations. In 30 extracted caries-free human molars, preparation for 60 mesio-occlusal and occluso-distal cavities (two cavities per tooth) occurred. With a CEREC 3 laser triangulation sensor and software-based construction analysis, the dimensions of the cavities at seven defined sites were measured. The cavities were randomized into four groups. Group 1 was restored with Ketac-Fil glass-ionomer cement, Group 2 with amalgam and Group 3 with Compoglass F compomer. In Group 4, Compoglass F was used in combination with photochromic Tetric Flow Chroma as a cavity liner. The completed restorations were then removed using 2x magnification and the cavities were once again controlled using the laser system. The duration of the removal procedure was also recorded. Changes in cavity dimensions (depth, height and width) following removal of the restorations were significantly smaller in Groups 1 and 2. Groups 3 and 4 were characterized by a significant overextension of the cavities compared to Groups 1 and 2 in all three dimensions. Group 4, with Tetric Flow Chroma as a cavity liner, showed better results than Group 3, but this improvement was not statistically significant. The duration of the removal procedure was significantly shorter in Group 2 than in the other groups.

Compomers↗
PubMedDate not supplied

Evaluation of focal epilepsy: a SPECT scanning comparison of 123-I-iomazenil versus HM-PAO.

PURPOSE: To establish whether regional disturbances of the benzodiazepine receptor distribution in focal epilepsies can be detected by SPECT using 123-I-Iomazenil. PATIENTS AND METHODS: Benzodiazepine receptor imaging was carried out in 10 patients interictally. To be eligible for this study the patients had to have a history of focal seizures and no evidence of routine imaging abnormalities as in CT or MR. The patients were selected on the basis of a regional decreased blood flow in HMPAO SPECT that correlated with the site of a stable unifocal EEG abnormality. Benzodiazepine receptor imaging was performed after intravenous administration of approximately 110 MBq 123-I-Iomazenil using SPECT. RESULTS: A regional reduced activity was found on sequential SPECT series after 30 and 90 min post injection in the receptor study. The brain region with a reduced receptor density was concordant to the pathologic finding in HMPAO SPECT in all patients. CONCLUSION: For the evaluation of patients with focal epilepsies lomazenil SPECT offers several advantages over HMPAO SPECT. Iomazenil binds specifically to the benzodiazepine receptor complex whereas the exact binding sites of HMPAO are still unknown. In contrast to HMPAO, lomazenil can be used for sequential SPECT examinations that may detect dynamic changes of the receptor complex. For the purpose of benzodiazepine receptor imaging, lomazenil is a suitable ligand in patients with focal epilepsies.

Adult↗
PubMedDate not supplied

Hemostatic evaluation of Sarns/3M-VAD implantation in calves.

The authors evaluated the potential for thrombotic complications arising from implantation of a ventricular assist device (Sarns/3M-VAD) in four calves. Coagulation screening tests (prothrombin time [PT], partial thromboplastin time [PTT], thrombin time [TT]), fibrinogen levels, and antithrombin III functional activity were found to be of little value as predictors of the degree of activation of the hemostatic system. However, platelet counts, adenosine diphosphate (ADP)- and collagen-induced platelet aggregation, and thromboxane (TXB2) levels were good indicators of changes in platelet reactivity. Platelet counts (initial value 6 x 10(5) rose, and were associated with increased rate and extent of ADP- and collagen-induced platelet aggregation, which remained elevated during the entire 25 day postimplantation period. The first 5 days postimplantation revealed a typical acute inflammatory response, with increased platelet levels, but with TXB2 levels significantly decreased during this period. A monoclonal antibody based bovine D-dimer assay and Western blot studies indicated a small but significant increase in circulating bovine D-dimer, indicating localized fibrin formation and its dissolution.

Animals↗
PubMedDate not supplied

[Size, structure, and dynamics of bile salt/lecithin mixed micelles (author's transl)].

The structure and size of lecithin/sodium glycocholate mixed micelles was investigated by quasi-elastic laser light scattering and spin label techniques. The investigations are in accordance with a bilayer model for these micelles. The order parameter and the phase transition enthalpy of the micellar bilayer were determined. The lateral and rotational diffusion constants of label molecules are compared with the corresponding diffusion constants in liposomes.

Chemical Phenomena↗
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[Epidemiological study of pulmonary hydatid cyst in the Ivory Coast. 3 cases].

No cases of echinococcus have been reported up to this time in Ivory Coast, where it has been considered non-existant in either pulmonary or hepatic form. The three cases of pulmonary echinococcus reported here show the classic paucity of clinical symptoms associated with classical radiological findings. The epidemiological research confirms in one case definite infection occurring in Ivory Coast and the other two either in the Ivory Coast or in closely neighbouring areas.

Adult↗
PubMedDate not supplied

[Tuberculosis in tropical Africa. Tuberculosis primary infection: some clinical aspects in tropical Africa].

A review of 140 cases of tuberculous patent primary infections from the hospital of Abidjan University and from an antituberculous unit. The disease begins slowly, general condition is rapidly altered, ventilation troubles are very frequent and so are complications as meningitis and miliary dissemination. In 11,4 p. cent of the cases, measles occurred before the primo-infection. In 38 p. cent of the cases the source of contamination could be identified and in one out of two cases, the mother proved to be responsible for it.

Adolescent↗
PubMedDate not supplied

Caroli's disease in two sisters. Diagnosis by ultrasonography and computed tomography.

Caroli's disease is a rare congenital disease with multiple segmental dilatations of the bile ducts. It may present in two forms: one (the simple form) with segmental dilatations only, and the other with dilatations combined with fibroangioadenomatosis, frequently complicated by portal hypertension. The disease is thought to be recessively inherited, but few familial cases have been reported. We have observed two sisters with the disease, one with the simple form, the other with fibroangioadenomatosis. Their case histories and diagnostic findings, with special reference to ultrasonography and computed tomography, are presented, and the potential for diagnosis by different imaging modalities is discussed.

Adult↗
PubMedDate not supplied

[Epidemiology of infections caused by human immunodeficiency viruses HIV-1 and HIV-2 in the Ivory Coast].

A study of antibodies to HIV1 and HIV2 has been performed among selected groups in Ivory Coast from January to December 1987. In total, 2,578 serum samples were examined. A seropositivity to HIV1 and/or HIV2 was observed in 32 (2.4%) of 1.334 healthy subjects of the general population from 5 different areas, 9 (3.6%) of 246 pregnant women, 58 (12.3%) of 471 blood donors, 72 (34.3%) of 210 female prostitutes, 23 (35.3%) of 65 patients with sexual transmitted diseases, 21 (35.6%) patients with chronic renal insufficiency and 98 (50.7%) patients with severe pulmonary tuberculosis. Among the 313 HIV antibodies carriers, the frequency of HIV1 infection (6.7%) was higher than HIV2 infection (2%). However, 3.4% had a double seropositivity HIV1 and HIV2.

Acquired Immunodeficiency Syndrome↗
PubMedDate not supplied

[Value of indirect immunofluorescence test in the diagnosis and prognosis of intestinal and extra-intestinal amoebiasis in endemic areas (author's transl)].

A comparative study of 108 patients with patient amoebiasis and a reference group of 85 free of the disease but living in endemic area. The positivity of the test has been more frequent and has given higher titers in the extra-intestinal forms than in the intestinal ones. The positivity rate in the reference group has been 15 per 100.

Amebiasis↗