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Biomedical subjects

M Wenzel

Publications and source records attributed to M Wenzel.

At least 91 records · Page 5Linked to original sources
PubMed1989

[Cell density of the corneal endothelium following cataract surgery].

Endothelial cell loss following extracapsular cataract extraction and implantation of a posterior chamber lens was studied and the influence of various factors analyzed. In 56 eyes, the mean reduction in cell density in the superior zone of the cornea was 19%. In the eyes with epithelial edema endothelial damage was more severe than average. Lower cell density was also found in particular in patients over 75 years old and those with pre-existing cornea guttata. In contrast, preexisting glaucoma, a history of corneal trauma, and, astonishingly, the surgeon's experience had no detectable influence on endothelial cell damage.

Aged↗
PubMed1989

[Corneal endothelial damage in congenital and juvenile glaucoma].

Corneal changes are typical for infantile glaucoma. In newborns, Descemet's membrane and the stroma are still soft, and distend when intraocular pressure rises. Cell counts were performed under the reflecting microscope to determine whether the endothelium is affected when corneal diameter increases and changes occur in Descemet's membrane. The mean endothelial cell density of 20 patients with congenital or secondary juvenile glaucoma, aged between 4 and 29 years, was found to be 2780/mm2. Even though increased corneal diameter was the most common primary symptom of buphthalmos, there were no relationships between corneal diameter on the one hand and postoperative endothelial cell density, visual outcome, or postoperative pressure on the other. In children who had had corneal edema followed by ruptures of Descemet's membrane the number of endothelial cells was significantly reduced, visual outcome was worse, and there were more problems with regulation of intraocular pressure. Lower-than-average endothelial cell densities were also found in some patients with secondary glaucoma.

Adolescent↗
PubMed1989

Pituitary hyposecretion and hypersecretion produced by a Rathke's cleft cyst presenting as a noncystic hypothalamic mass.

A 53-year-old man presented with polydipsia, polyuria, lightheadedness on standing, and syncope. Visual field deficits suggesting left optic tract compression and pituitary dysfunction consisting of diabetes insipidus, hyperprolactinemia, and anterior pituitary insufficiency were diagnosed. On the computed tomography scan, an isodense, ring-enhancing, parasellar mass was localized primarily in the suprasellar region and also extended into the sella. It was believed that the pituitary hormone hypersecretion and hyposecretion were due to hypothalamic dysfunction from the mass which was initially believed to be a craniopharyngioma. At surgery a Rathke's cleft cyst was resected. The unusual presentation of this Rathke's cleft cyst presenting as a hypothalamic lesion is discussed.

Craniopharyngioma↗
PubMed1989

[Effects of different buffers, ethanol and hydrogen peroxide on the morphology of cultured brain cells].

Effects of different buffers: N-2-Hydroxyethylpiperazine-N-2-ethanesulfonic acid (HEPES), Ethanolamine (2-Aminoethanol), sodium bicarbonate (NaHCO3) in the presence of 0.003% H2O2 or 0.5% ethanol were investigated on cell cultures from brain (chick embryo 5 1/2 or 9 day in ovo). Morphological parameters: density of cells, reaggregation, size of cell aggregates were used. H2O2 in the presence of NaHCO3 led to a decrease of isolated cells and an increase of reaggregation with degeneration in the great clusters. When H2O2 and 5 mM HEPES were present together in the absence of NaHCO3, the aggregation was less than with HEPES alone. By use of a chemical defined medium DME/F-12 supplemented with Insulin, Transferrin, sodium selenite, bovine serum albumin and 15 mM HEPES both the number and the diameter of cell aggregates increased. Addition of 0.5% ethanol in the presence of NaHCO3 stimulated in cultures of the ganglion trigeminale and telencephalon (9 day chick embryos) the regeneration of neurites and the proliferation and migration of non-neural cells. No growth of neurites was observed on the same condition in brain cultures from 6 day chick embryo. The number of large aggregates increased significantly in the presence of NaHCO3 and in the chemical defined and supplemented medium DME/F-12. Bologa et al. (1987) demonstrated that the buffers TREA (Triethanolamine) and HEPES enhance the expression of properties related to post-mitotic differentiated cellular states in both neurons and glia.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1989

[Evaluation of inflammatory reactions following cataract surgery].

Following cataract extraction 179 patients were examined with a slit-lamp using focal and specular illumination. 163 of them had received an intraocular lens (IOL). The cells (granulocytes) and flare-up in the anterior chamber decreased during the first postoperative days, while the cellular growth on the IOLs (macrophages) did not decrease in the same period. No correlations could be found between the cells, the flare-up in the anterior chamber, and the cellular growth on the IOLs. All three seem to be independent inflammatory reactions that occur following cataract extraction.

Anterior Chamber↗
PubMed1988

Preferential inhibition of 5-lipoxygenase activity by manoalide.

Treatment of human polymorphonuclear leukocytes (PMNLs) with micromolar concentrations of the anti-inflammatory drug manoalide inhibited production of leukotriene B4 (LTB4) and LTC4/LTD4 in response to the calcium ionophore A23187. In an attempt to further define the mechanism(s) of action of this agent, we have examined its interaction with several lipoxygenase enzymes. In RBL-1 cells, manoalide inhibited 5-lipoxygenase (5-LO) activity with an approximate IC50 of 0.3 microM. This was equipotent in our system with the known lipoxygenase inhibitor nordihydroguaiaretic acid (NDGA). Manoalide was virtually inactive, however, against 12-lipoxygenase activity in both human platelets and mouse epidermis, with little inhibition seen at concentrations up to 100 microM. Manoalide showed some activity against soybean lipoxygenase, although it was 30- to 50-fold less potent than as an inhibitor of the 5-lipoxygenase enzyme. These data indicate that manoalide is a selective 5-LO inhibitor and suggest the possibility that its anti-inflammatory actions may be due, at least in part, to inhibition of leukotriene synthesis.

Anti-Inflammatory Agents↗
PubMed1988

Cellular invasion on the surface of intraocular lenses. In vivo cytological observations following lens implantation.

Cellular growth on intraocular lenses can be observed by using a specular microscope. We examined in vivo the cellular pattern on the surface of implanted lenses during the early postoperative period in 63 patients. In every case inflammatory cells were noted on the lens surface at some point during the observation period. These often showed a spindle-like appearance resembling fibroblasts. The density of the cell population increased during the following days but usually did not exceed 100 cells/mm2. From the end of the first week, multinucleated giant cells may appear. In one case, a patient with a severe postoperative iritis and hypopyon demonstrated an extremely pronounced and long-lasting cellular proliferation.

Cataract Extraction↗
PubMed1988

[Ferrocene, ruthenocene and rhodocene analogs in haloperidol synthesis and organ distribution after labeling with 103Ru and 103mRh].

Ferrocene-Haloperidol was synthesized by N-alkylation of 4-(4'-chlorophenyl)- 4-hydroxypiperidine with 1-ferrocenyl-4-chlor-butan-1-on. By heating the ferrocene-haloperidol with 103RuCl3 the 103Ru-labelled ruthenocene-haloperidol was obtained. This compound showed a high affinity for lung but not for brain in rats and mice. The decay of the 103Ru labelled compound results in the formation of the 103mRh labelled rhodocene-haloperidol, which is rapidly oxidized by air to the corresponding rhodocinium-haloperidol. This compound can be separated by extraction and TLC.

Animals↗
PubMed1988

[A classification of intraocular bacteriologic findings following lens implantation].

Findings in seven patients with intraoperative bacterial invasions are reported. These invasions were classified in three stages of severity: (1) According to the literature it may be assumed that clinically undetectable invasion occurs in more than 10% of all operations. The bacteria detected in one case may have been a secondary finding in an electron-microscopic study. (2) A benign endophthalmitis caused by Staphylococcus epidermidis was found in three patients. The symptoms initially prompted the incorrect diagnosis "toxic lens syndrome". Cells resembling leukocytes were detected on the lenses by light microscopy. Following explantation of the lens and the posterior capsule, patients' vision slowly recovered to an average of 0.8. (3) Of three patients with fulminant panophthalmitis caused by Enterococci and/or Staphylococcus epidermidis, only one patient re-attained 0.5 vision, after two weeks; in the second case vision remained restricted to "hand movements", and in the third the eye had to be enucleated.

Aged↗
PubMed1988

[Not Available].

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Education, Medical↗
PubMed1988

[Not Available].

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Germany↗
PubMed1988

[The effect of methionine enkephalin, leucine enkephalin and the hexapeptide, dalargin on the morphology of cultured neurons].

Cell cultures derived from brain, ganglion trigeminale or retina of 5- and 9-day-old chick embryos and from brain stem or hippocampus of 16-18 day-old fetal rats were treated with Met5-, Leu5-enkephalin, or Dalargin--a synthetic hexapeptide structurally related to Leu5-enkephalin--and evaluated morphologically. The treatment of the nervous tissue cultures with the peptides markedly affected their growth pattern. Aggregates of glial and neuronal cells were surrounded by flat cells forming monolayer network structures. In cultures of brain from 5 day-old chick embryos the proliferation of the cells was significantly stimulated. No growth of neurites was observed. It is discussed that the tested Enkephalins and in the same way the Dalargin may play an important role in the early neuronal development. Their activity in phase 0 and phase 1 of the life history of nerve cells indicates aspects of temporary peptide influences. Excess of glial cells caused by the tested peptides did not enhance neuronal differentiation. The transdifferentiation of developing receptor cells into ependymal cells during the adaptation process in retina cultures as a special effect of Dalargin is discussed. The present findings suggest that the influence of (opioid) peptides in vitro may be detected morphologically and that nervous tissue culture is a valuable tool for differentiating neuronotrophic neurite-promoting and neurotoxic drug effects.

Animals↗
PubMed1988

Scanning electron microscopical observations on telencephalon explants cultivated in vitro.

Telencephalon explants from 10 or 12 days old chicken embryos were cultivated 2 days in vitro and investigated by SEM. Already at that day, nerve fibres forming thick fasciculi were observed in the outgrowth region of the explant. Neuritic growth cones of the filiforme, or lamellipodiale type were demonstrated as well as button-like dendritic growth cones. The cell somata of bipolar or multipolar neuroblasts and pyramidal neurons could be distinguished from those of astrocytes. Some nerve fibres establish axosomatic or axodendritic contacts, basket-like arrangements of axon terminals around small neuroblasts were found.

Animals↗
PubMed1987

[Separation of [Rh-103m]-rhodocene derivatives from the parent [103Ru]ruthenocene derivatives and their organ distribution].

The radioactive decay of [103Ru]ruthenocene derivatives leads to 103mRh labelled rhodocinium derivatives, which can be separated by the extraction of a lipophilic solution of the ruthenocen derivate with water. The separation factor 103mRh/103Ru reaches values of 32:1 Rh3+ ions are not liberated and extracted. The organ distribution of the 103mRh labelled rhodocinium derivatives gained from ruthenocene and from N-isopropyl-ruthenocene amphetamine is different from the distribution of the parent ruthenocene compound. The liver and kidney uptake of the rhodocinium-amphetamine is much higher than the uptake with ruthenocene amphetamine.

Animals↗
PubMed1987

[Biomicroscopy of an intraocular lens. Comparison of specular microscopy findings with the cytologic specimen].

Seventeen months after implanting an anterior chamber intraocular lens the lens had to be removed because of secondary glaucoma and retinal hemorrhage. The lens had been examined 5 days prior to surgery. It appeared that histiocytic giant cells and fibroblasts had settled on its surface. This was subsequently confirmed by cytological studies. It therefore appears possible to describe an in vivo differential cytology and to diagnose the type of inflammatory reaction in vivo.

Aged↗