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G Rode

Publications and source records attributed to G Rode.

50 records · Page 3Linked to original sources

Vertigo and upside down vision due to an infarct in the territory of the medial branch of the posterior inferior cerebellar artery caused by dissection of a vertebral artery.

A 48 year old woman developed an acute vestibular syndrome associated with upside down vision a few hours after minor cervical trauma. Magnetic resonance imaging showed an ischaemic lesion in the territory of the medial branch of the posterior inferior cerebellar artery. An arteriogram showed a dissection of the left extracranial vertebral artery.

Aortic Dissection↗

[Vaginal sonography: pilot study for using in ovarian screening procedures].

From May to September 1987, 221 women of over 45 years of age were examined by transvaginal ultrasound at the Department of Gynaecology (Gynaecological Hospital) of the University of Marburg. Transvaginal ultrasound proved to be significantly superior to clinical examination, since palpation had resulted in "NAD" findings in all cases. The average diameter and the volume of postmenopausal ovaries, determined by transabdominal sonographic studies, were easily confirmed by the new method. In 6% of the 221 patients, pathological findings of the ovaries were clinically "NAD". Since the usefulness of transabdominal ultrasound in screening for ovarian cancer has already been confirmed by other authors, this pilot study aims at providing an opportunity to test transvaginal ultrasound also in a large ovarian cancer screening programme by furnishing the essential basic research data. Age-adapted average ovarian sizes and significant differences in size between the right and the left ovary were used to differentiate between normal and pathological findings as well as changes in the ovarian parenchymal patterns.

Aged↗

O6-Methylguanine repair of methylated DNA in vitro: cell cycle-dependence of rat liver methyltransferase activity.

O6-Methylguanine DNA transferase activity was investigated in liver proteins obtained at various intervals after partial hepatectomy and/or after hydroxyurea-induced synchronization of the liver cell cycle. Liver proteins were incubated with 3H-methylated calf thymus DNA as previously described by Pegg et al. (1981). The loss of O6-methylguanine was measured by radiochromatography of DNA hydrolysates. The extent of O6-methylguanine repair differed during the cell cycle: the activity increased in late G1, reached a maximum in early S phase and declined in late S phase and G2M. These results indicate that hepatocytes are endowed with an increased DNA repair capacity for this promutagenic lesion during the period of highest transformation sensitivity in the cell cycle. Though increased, however, this repair potential does not, because of its exhaustibility, appear to be sufficient to prevent initiation of transformation after high doses of alkylating carcinogens.

Animals↗

Cell proliferation and DNA repair in the liver during early stages of chemical carcinogenesis.

X-chromosomal phosphoglycerate kinase mocaicisms in organ samples of female heterozygous mice provided a means to prove, because of a selective expression of one of the two allozymes, the clonal origin of carcinogen-induced preneoplastic hepatocellular populations (see also ref. 61). The occurrence of these clonal preneoplastic foci was used in rats to determine cell cycle dependent differences of transformation sensitivity and DNA repair. The highest transformation rate was found after carcinogen exposure in late G1/early S phase of the cell cycle. Experimental disturbance of DNA precursor pools by continuous thymidine infusion during carcinogen exposure results in an increased formation of preneoplastic clones. This is a further argument in favor of an essential role of base-mispairing during initiation. Cell cycle dependent fluctuations of O6-methylguanine DNA transferase with an increasing enzyme activity in late G1 and a maximum in early S phase indicate that cells possess an increased potential for eliminating promutagenic O6-methylguanine during the most transformation sensitive parts of the cell cycle to prevent base-mispairing during DNA replication or transcription. However, this putatively protective effect is limited because the enzyme is rapidly expended in the reaction and drops again in later stages of the cell cycle.

2-Acetylaminofluorene↗

O6-methylguanine repair in liver cells in vivo: comparison between G1- and S-phase of the cell cycle.

To compare the formation and persistence of alkylated DNA bases in the G1- and S-phase compartments in liver in vivo, regenerating rat liver was exposed to [14C]dimethylnitrosamine (0.57 mg/kg, IP injection) or N-[methyl14C]-N-nitrosourea (3.3 mg/kg, intraportal injection) during the G1 phase of the cell cycle (12 h after partial hepatectomy), or at 24 h after partial hepatectomy with 30% hepatocytes in DNA synthesis, or at 43 h after partial hepatectomy, 4 h after an hydroxyurea block from 14 to 39 h after operation with 80% hepatocytes in DNA synthesis. At 120 min after dimethylnitrosamine and 90 s, 5, 10, or 60 min after the intraportal pulse of N-methyl-N-nitrosourea the molar fractions of 7-methylguanine (7megua), O6-methylguanine (O6megua), and 3-methyladenine (3mead) and of metabolically labeled guanine were determined from DNA hydrolysates by Sephadex-G10 radiochromatography. After dimethylnitrosamine only minor differences were observed for 7megua formation in the three groups; the 3mead/7megua ratio remained constant irrespective of the number of cells in S phase. In contrast, the O6megua/7megua ratio revealed a loss of O6megua, the extent of which appeared proportional to the fraction of DNA-synthesizing cells in the liver. The rapid loss of O6megua in S-phase cells was confirmed after intraportal administration of N-methyl-N-nitrosourea. During the first 10 min after the methylnitrosourea pulse the O6megua/7megua ratio was constant in G1 cells and dropped from 90 s to 10 min by about 15% in liver containing 30% S-phase cells and by about 40% with 80% cells in DNA synthesis. DNA-synthesizing hepatocytes are apparently endowed with a higher O6megua DNA transferase activity than nonproliferating liver cells. The rapid, though exhaustible elimination of O6megua during S-phase might result in partial protection of DNA-synthesizing cells from base-mispairing and/or from hypomethylation at G-C sites.

Alkylation↗

[The influence of disodium cromoglycate (DNCG) on the phagocytotic activity of neutrophile granulocytes (author's transl)].

Disodium cromoglycate (Intal) inhibits in vitro the phagocytotic activity of neutrophile granulocytes. In thirteen pairs of blinding analysed experiments it could be shown that the DNCG incubatet blood samples had a phagocytotic index below that of the control. The statistical significance of these findings was assessed by a variance analysis.

Analysis of Variance↗

[Relations between cell-bound lipids and disodium cromoglycate (author's transl)].

Disodium cromoglycate binds in vitro and in vivo to lipids in white cells. Smears of cells from lymphocyte cultures and from bone marrow aspirates treated with DNCG and subsequently stained with pseudoisocyanine show a characteristic green fluorescence (515 nm) of membrane- and intracellular-lipids. It is suggested that the mode of action of DNCG in the prophylaxis of bronchial asthma could be the binding of DNCG to membrane lipids. This binding might block the IgE-mediated reaction on the surface of mast cells which otherwise would lead to degranulation and release of vasoactive substances.

Bone Marrow Cells↗

[Acid mucopolysaccharides in human blood and bone marrow cells shown by fluorescence microscopy (author's transl)].

In lymphocytes, monocytes and basophil granulocytes of patients with mucopolysaccharidosis specific fluorescence of acid mucopolysaccharides exists after fixation of blood smears with 9-aminoacridin-hydrochloride and subsequent staining with pseudoisocyanine at pH 4.2. A total of eleven children with various types of mucopolysaccharidosis were investigated. Specificaly stained granula were demonstrated in 5 to 49 percent of all lymphocytes and monocytes. Acid mucopolysaccharides were for the first time also shown in red-cell precursors of the bone marrow of children with mucopolysaccharidosis.

Acridines↗