Search PubMed⌕ Search

Biomedical subjects

G Raabe

Publications and source records attributed to G Raabe.

At least 19 recordsLinked to original sources
PubMed2002

[Paraneoplastic pityriasis rubra pilaris in metastatic adenocarcinoma without diagnosable primary].

HISTORY AND ADMISSION FINDINGS: A 75-year-old woman, without a history of severe illness, developed an erythematosquamous skin disease on hands and forearms. After continued spreading of these cutaneous lesions, she was admitted to hospital, presenting with a generalised desquamating erythrodermia and marked pruritus. INVESTIGATIONS: Skin biopsy showed cornocutaneous signs with alternating ortho- and parakeratosis, typical for pityriasis rubra pilaris. Laboratory findings showed a chronic to acute inflammation with leukocytosis, granulocytosis in the differential blood count, raised C-reactive protein in a range from 54.7 to a maximum of 157.2 mg/l and a protein electrophoresis with elevated alpha1- and alpha2-fraction. TREATMENT AND COURSE: The erythrodermia only temporarily receded under systemic therapy with acitretin and prednisolone. The patient developed intermittent septic fever accompanied by reduction or loss of consciousness. The general condition of the patient worsened considerably. Out of a rapidly progressing pleural effusion malignant cells similar to adenocarcinoma were isolated. Because CA15-3 was elevated we conducted an extended search especially for a breast carcinoma, but found only pathologically enlarged axillary, mediastinal and abdominal lymph nodes in conventional X-ray, CT, ultrasound and endoscopic procedures. The patient died from paraneoplastic pulmonary embolism. At autopsy, the widespread metastatic dissemination from poorly differentiated adenocarcinoma was confirmed. A necrosis in the right breast containing tumour cell remnants could probably be regarded as the primary neoplasm. Immunohistochemically no definite proof of breast nor gastro-intestinal carcinoma could be found. CONCLUSIONS: This case presents a rare paraneoplastic cutaneous manifestation as pityriasis rubra pilaris triggered by a poorly differentiated adenocarcinoma. The primary neoplasm could not definitely be identified, neither pre nor post mortem.

Acitretin↗
PubMed2001

Synthesis and structure of, and bonding in some derivatives of 2,6,9,10-tetraoxatricyclo[3.3.1.1(3,8)]-decane.

Five derivatives of 2,6,9,10-tetraoxatricyclo[3.3.1.1(3,8)]decane were synthesized and their molecular structures in the solid state were determined by means of X-ray diffraction analysis. In addition, the structures of all the molecules were optimized at different levels of computational quantum chemistry (HF/6-31G*, B3LYP/6-31G*). Experimentally determined bond lengths were compared with their calculated counterparts, and striking differences between the Hartree-Fock (HF) results and the experimental data could be traced back to the lack of correlation energy in the geometry optimizations. Two of the compounds under consideration are diastereomers and their relative stability was not only calculated with a conventional ab initio method (ZPE+MP2/6-31G*//HF/6-31G*), but also within the framework of density functional theory (B3LYP/6-31G*). In some of the calculations the influence of the solvent was included in single point calculations by means of an electrostatic model. Moreover, combining experimental as well as computational results, the exclusive axial orientation of a Cl atom in one of the compounds could be explained by an interplay of kinetic and energetic effects.

Journal Article↗
PubMed2000

Morphology of coronary atherosclerotic lesions in patients with end-stage renal failure.

BACKGROUND: An excessive rate of cardiac death is a well-known feature of renal failure. Coronary heart disease is frequent and the possibility has been raised that the natural history of the coronary plaque is different in uraemic patients. We assessed the morphology of coronary arteries in patients with end-stage renal failure and compared them with coronary arteries of matched non-uraemic control patients. METHODS: Fifty-four cases were identified at autopsy who met the inclusion criteria: cases, end-stage renal disease (n=27); controls, non-renal patients with coronary artery disease (n=27). At autopsy all three coronary arteries were prepared at corresponding sites for investigations: (i) qualitative analysis (after Stary), (ii) quantitative measurements of intima and media thickness (by planimetry), (iii) immunohistochemical analysis of the coronary plaques and (iv) X-ray diffraction of selected calcified plaques. RESULTS: Qualitative analysis of the coronary arteries showed significantly more calcified plaques of coronary arteries in patients with end-stage renal failure. Plaques of non-uraemic patients were mostly fibroatheromatous. Media thickness of coronary arteries was significantly higher in uraemic patients (187+/-53 microm vs 135+/-29 microm in controls) and intima thickness tended to be higher (158+/-38 microm vs 142+/-31 microm) but this difference was not statistically significant. Plaque area (4.09+/-1. 50 mm(2) vs 4.39+/-0.88 mm(2)) was comparable in both groups. Lumen area, however, was significantly lower in end-stage renal patients. Immunohistochemical analysis of the cellular infiltrate in coronary arteries showed no major differences in these advanced plaques of uraemic and non-uraemic subjects. CONCLUSION: Coronary plaques in patients with end-stage renal failure are characterized by increased media thickness and marked calcification. In contrast to the previous opinion the most marked difference compared to non-uraemic controls does not concern the size, but the composition of the plaque. Deposition of calcium within the plaques may contribute to the high complication rate in uraemic patients.

Aged↗
PubMed1999

Asymmetric Synthesis of Novel Ferrocenyl Ligands with Planar and Central Chirality.

A stereogenic center at the position beta to the metallocene backbone is present in ferrocenyl ligands 2, which are interesting for asymmetric catalysis. These planar-chiral compounds are accessible for the first time by a highly diastereoselective and enantioselective synthesis (de=93-97 %; ee>/=96 %) from the ferrocenyl ketones 1. A variety of donor groups (E(1)=Ph(2)P small middle dotBH(3), SMe, SiPr; E(2)=SMe, STol, SePh, Ph(2)P small middle dotBH(3), iPr(2)P small middle dotBH(3)) can be introduced as electrophiles. Tol=tolyl=CH(3)C(6)H(4).

Journal Article↗
PubMed1999

[Problems in diagnosis and therapy of juxtapapillary, tubulovillous adenoma].

UNLABELLED: Tubulovillous adenoma of the duodenum have a high potential for malignant transformation. An exact preoperative staging and an accurate histological examination are essential in order to choose a proper therapeutic strategy. We report on difficulties in the diagnostic and therapeutic process of a patient with a tubulovillous, juxtapapillary, duodenal adenoma. The adenoma had been resected by means of submucosal excision after infiltrative growth had been excluded endosonographically and malignancy had been ruled out by the histological examination of a taken biopsy. Furthermore no malignant changes had been found in the resected material. However an early recurrence of the tumor questioned the correctness of the first diagnosis. In fact, a retrospective histological examination of the resected specimen revealed an adenocarcinoma, which had been overlooked primarily. Finally the patient underwent duodenopancreatectomy and remains without signs of tumor recurrence so far. CONCLUSIONS: 1. Microinvasion of the submucosa can not be excluded endosonographically. Therefore endosonography can not specify the dignity of an unknown tumor with a sufficient safety, especially if there is only an intramural growth of the tumor without transmural spread. 2. Because of high recurrence rates and a distinct frequency of malignant transformation of duodenal adenomas, a submucosal resection should only be performed in high-risk patient. 3. In that patients the resected material has to be examined as accurately and subtly as possible to rule out a submucosal microinvasion. 4. Based on the above mentioned radical surgery (duodenopancreatectomy) should be performed in all normal risk patients with juxtapapillary adenomas.

Adenocarcinoma↗
PubMed1998

[Value of endosonography in diagnosis of diffusely growing stomach carcinomas].

The diagnosis of diffuse type gastric carcinoma is very difficult. The delay of diagnosis is often due to false-negative endoscopic and histologic evaluation. The architecture of the stomach can be clearly visualized by endosonography. Therefore, already minor destructions of the gastric layers can be found. The endosonographic picture includes the presence of the layers, which are larger and of irregular contour. In infiltrating gastric cancer typically the submucosal layer and the muscularis are concentrically enlarged and appear folded. Based on the endosonographic picture diffuse type gastric carcinoma has been diagnosed in 32 patients. When compared to the histologic diagnosis after gastrectomy or autopsy the accuracy of the endosonographic diagnosis was 87.5%, (28 out of 32 patients). From the remaining four patients diagnosed to have diffuse type gastric cancer by endosonography three patients turned out to have malignant infiltrating tumors of different histologies. Therefore, the positive predictive value of endosonography in detection of infiltrating malignant tumors was 96.8% in our group. In contrast the accuracy of preoperative histologic diagnosis by biopsies was only 58%. Suspicious results of gastroscopy, especially in combination with a negative biopsy, should lead to further evaluation by endosonography to detect diffuse type gastric cancer earlier.

Adenocarcinoma, Scirrhous↗
PubMed1996

Enantioselective inhibition of TNF-alpha release by thalidomide and thalidomide-analogues.

The question whether the immunomodulating activity of rac-thalidomide resides in either the (-)-(S)- or the (+)-(R)-enantiomer was addressed by synthesis and separation of pure enantiomers of thalidomide analogues which carry a methyl-group at the asymmetric carbon atom and are thus prevented from racemization. The effect of the pure enantiomers of the thalidomide-analogues and also of the enantiomers of thalidomide on release of TNF-alpha was tested in vitro by using stimulated peripheral mononuclear blood cells. Both enantiomers of thalidomide inhibited the release of TNF-alpha equally well at low concentrations (5 and 12.5 micrograms/ml) but at higher concentrations (25 and 50 micrograms 50 micrograms/ml) there was a weak but statistically significant selectivity towards the (-)-(S)-enantiomer. In the case of the configuration-stable thalidomide-analogues there was a very pronounced and statistically significant enantioselectivity towards the (S)-form even at lower concentrations (> or = 5 micrograms/ml). The (S)-enantiomers of the thalidomide-analogues differed in their inhibitory potency from (-)-(S)-thalidomide suggesting that the introduction of the methyl-group increases the TNF-alpha-inhibitory activity while the reduction of one of the carbonyl-functions in the glutarimide-moiety to a methylene-group decreases activity. The effect of these small molecular alterations on activity and the enantioselectivity towards the (S)-enantiomers may indicate that thalidomide and its analogues directly interact with one or several cellular target-proteins.

Cells, Cultured↗
PubMed1995

Guidelines for application of meta-analysis in environmental epidemiology. ISLI Risk Science Institute.

The use of meta-analysis in environmental epidemiology can enhance the value of epidemiologic data in debates about environmental health risks. Meta-analysis may be particularly useful to formally examine sources of heterogeneity, to clarify the relationship between environmental exposures and health effects, and to generate information beyond that provided by individual studies or a narrative review. However, meta-analysis may not be useful when the relationship between exposure and disease is obvious, when there are only a few studies of the key health outcomes, or when there is substantial confounding or other biases which cannot be adjusted for in the analysis. Recent increases in the use of meta-analysis in environmental epidemiology have highlighted the need for guidelines for the application of the technique. Guidelines, in the form of desirable and undesirable attributes, are presented in this paper for various components of a meta-analysis including study identification and selection; data extraction and analysis; and interpretation, presentation, and communication of results. Also discussed are the appropriateness of the use of meta-analysis in environmental health studies and when meta-analysis should or should not be used.

Environmental Exposure↗
PubMed1992

Cytokeratin pattern of clinically intact and pathologically changed oral mucosa.

The various cytokeratin polypeptides in oral epithelia are expressed in dependence on site and formation of a stratum corneum. Certain cytokeratins occur permanently and others occasionally. In fibrous hyperplasia and Lichen ruber planus, patterns of cytokeratins did not deviate significantly from normal. In some but not all cases of squamous cell carcinoma and leukoplakia studied, marked aberrations of pattern were characterized by (i) appearance of cytokeratin No. 19, (ii) somewhat more frequent occurrence of cytokeratins Nos. 8 and 18, (iii) proteolytic modifications of cytokeratins, and (iv) partial loss of a few site-specific cytokeratins. The aberrations may be taken as additional diagnostic criteria for differentiation between non-aggressive and potentially aggressive leukoplakic lesion, even if they are not correlated with the conventional histological grading of dysplasia.

Adolescent↗
PubMed1990

[Hyperplasiogenic polyps and stomach carcinoma risk--experiences following 1074 polypectomies and follow-up studies].

In 731 hyperplasiogenic polyps which have been removed by endoscopical polypectomy there were ten polyps with an early cancer and eight polyps with severe dysplasias (borderline lesions) as well as one polyp, in which an advanced carcinoma had developed. This is to date the greatest series of hyperplasiogenic polyps with malignant transformation. In addition, in nine patients with hyperplasiogenic polyps carcinomas could be discovered, i.e. a rate for malignancy of 3.8%. It seems that stomachs with multiple polyps are particularly endangered. The recurrence rate on follow-up examinations covering a period of up to eight years was 36.1%.

Cell Transformation, Neoplastic↗
PubMed1990

Discordant findings in chorionic villus direct preparation and long term culture--mosaicism in the fetus.

Prenatal cytogenetic study of chorionic villi showed a discrepancy between a normal female karyotype 46,XX in the direct preparation after short-term incubation, and a 45,X karyotype in the long-term culture. The subsequent amniocentesis revealed a normal karyotype in three cultures and a 45,X/46,XX mosaicism in one culture. Cytogenetic analysis of chorionic villi after termination of the pregnancy showed a normal karyotype in the direct preparation and a 45,X/46,XX mosaicism in the long-term culture. Fetal lymphocytes showed normal karyotypes, whereas fibroblast cultures revealed a 45,X/46,XX mosaicism.

Chorionic Villi Sampling↗
PubMed1990

Cell proliferation in chorionic villi at different gestational ages, as analyzed by premature chromosome condensation.

The technique of premature chromosome condensation (PCC) was adapted to human first-trimester chorionic villi cells to analyze the cell-cycle kinetics of interphase chromatin. Uncultured cells of the cytotrophoblast (CT) and the mesenchymal core (MC) were obtained by a two-step digestion. PCC was induced by fusion of the chorionic interphase cells with mitotic Chinese hamster ovary or HeLa cells. Cells showing PCC in G1 (classes 1-6), S, and G2 were found. To analyze further the proliferation stages of chorionic G1 interphases, the proliferation potential index (PPI) of 34 placentae recovered between the 8th and 12th week of gestation was determined. The mean PPI found in the CT and MC cells ranged from 18% to 73%, values similar to those described for intensely proliferating tissues. The highest mean PPI value (73%) was observed in CT cells from placentae recovered at the 9th week of gestation, indicating a high specific proliferative activity of CT cells at this developmental stage.

Animals↗
PubMed1990

Paracentric inversion 14.

A new familial case of paracentric inversion of chromosome 14 inv(14)(q24.1q32.1) ascertained by multiple abortions in a female carrier is presented. A review of the literature revealed 14 cases of paracentric inversion 14 recorded so far. According to the different breakpoints, two major groups of inversions of the long arm of chromosome 14 can be recognized.

Abortion, Habitual↗
PubMed1990

[Comparative experimental animal studies for testing the usefulness of formalin- and glutaraldehyde-pretreated umbilical cord veins as artery replacements].

Formalin-fixed (F) and glutaraldehyde-pretreated (G) umbilical veins (n = 24) were interposed in the infra-renal aorta of dogs. The follow-up period was 1 year. Early complications with significant differences included 2 occlusions and 3 deaths (41.6%) in group F, 1 occlusion and 1 death (16.6%) in group G. Ten animals of group G and 7 of group F were alive at 1 year, 7 transplants of each of both groups were angiographically and macroscopically patent (25%). Four aneurysms (33.3%) existed angiographically and showed good collateral circulation angiographically (25%). Four aneurysms (33.3%) existed angiographically and macroscopically in group F (statistically significant). Histologically, group G was found to have a delayed resorption and an earlier beginning of connective-tissue proliferation as compared to group F. Considering early and late findings, G-pretreatment is preferable to F-treatment of umbilical veins.

Animals↗