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Biomedical subjects

M Goerig

Publications and source records attributed to M Goerig.

At least 73 records · Page 4Linked to original sources
PubMed1990

Prostanoid release in experimental liver transplantation.

Prostanoids are biologically active mediators of inflammation and tissue injury. To investigate the role of prostanoids in orthotopic liver transplantation we used a porcine model and determined prostaglandin E2, 6-keto-prostaglandin F1 alpha, and thromboxane B2 in arterial, portal, and hepatic venous blood during organ harvesting, the recipient operation, and the early postoperative period. There were no significantly increased serum levels during the donor operation or at the end of cold storage. As early as 1 or 5 min after initiation of reperfusion of the transplanted organ, prostanoids in hepatovenous blood increased dramatically (100-500-fold). Changes in arterial and portal blood (10-50-fold) were less pronounced but still statistically significant. In surviving animals these values returned to normal within 24 hr. The hepatic release of metabolites of the arachidonic acid cascade after liver grafting indicates that the synthesis of prostanoids might contribute to morphological and functional alterations of the transplanted graft. In addition, the increased arterial values of circulating prostanoids may potentially participate in severe cardiovascular, hemostatic, and immunological alterations known to occur after liver transplantation.

6-Ketoprostaglandin F1 alpha↗
PubMed1990

[Georg Perthes--a pioneer of modern regional anesthesia technics?].

In regional anesthesia, the localization of peripheral nerves and plexuses is possible by means of mechanical or electrical stimulation. Electrical stimulation for this purpose was first described in 1912 by the surgeon Georg Perthes (1869-1927) of Tübingen, who reported his own experiences. The original description and results of electrostimulation are transposed upon a modern point of view of regional anesthesia.

Anesthesia, Conduction↗
PubMed1989

Increased bioavailability of enzymes of eicosanoid synthesis in hepatic and extrahepatic tissues after portacaval shunting.

Metabolites of arachidonic acid have been attributed to severe circulatory, metabolic and hormonal alterations in patients with chronic liver disease. In order to study changes of the tissue-specific availability of enzymes of eicosanoid synthesis, we used portacaval-shunted rats, as this model exhibits many clinical and biochemical similarities to patients suffering from cirrhosis of the liver. Microsomal mass and maximal velocity of prostaglandin H synthase, the initial enzyme of prostaglandin synthesis, were markedly and permanently increased after shunting in both hepatic and extrahepatic tissues as compared to those of sham-operated rats. Maximal velocity of thromboxane synthase and prostacyclin synthase, two more peripheral enzymes of the arachidonic acid cascade, were tissue-specifically enhanced, whereas the apparent affinities (Km) remained unchanged. Determination of 5-lipoxygenase activity in tissue preparations disclosed a preferential increase in the liver, lung and renal cortex after portacaval shunting. Furthermore, exposure to endotoxin closely mimicked the shunting-induced changes. These results suggest that after portacaval shunting and possibly in patients with advanced liver disease, profound abnormalities at the level of local enzyme expression might play a pathophysiologically important role in the control of eicosanoid synthesis.

6-Ketoprostaglandin F1 alpha↗
PubMed1989

Early reversible induction of leukotriene synthesis in chicken myelomonocytic cells transformed by a temperature-sensitive mutant of avian leukemia virus E26.

We used chicken myelomonocytic cells transformed by a temperature-sensitive mutant of the myb/ets oncogene-containing avian leukemia virus E26 to study the regulation of leukotriene (LT) synthesis during macrophage differentiation. Cells exposed to arachidonic acid and the Ca2+ ionophore 23187 produced up to 180 times more LTs at the nonpermissive temperature (42 degrees C) than at the permissive temperature (37 degrees C). Induction of LT synthesis was detectable within 2 hr after temperature shift, whereas conventional macrophage markers became evident after 2-3 days. N-Formylmethionylleucylphenylalanine, opsonized zymosan, and complement factor C5a induced LT synthesis in temperature-sensitive mutant-transformed cells only when the cells were maintained at 42 degrees C, and this effect was blocked by pertussis toxin. When cells were kept at 42 degrees C for 48 hr and then shifted back to 37 degrees C to induce retrodifferentiation, LT synthesis rates declined within 8 hr and reached near control values within 36 hr. Retrodifferentiation also led to decreased LT synthesis in response to N-formylmethionylleucylphenylalanine, opsonized zymosan, and C5a. These results indicate that activation of the 5-lipoxygenase pathway is a very early event in the macrophage differentiation pathway that is directly or indirectly controlled by the temperature-sensitive v-myb protein.

Animals↗
PubMed1988

Evidence for coordinate, selective regulation of eicosanoid synthesis in platelet-derived growth factor-stimulated 3T3 fibroblasts and in HL-60 cells induced to differentiate into macrophages or neutrophils.

We used Swiss 3T3 fibroblasts stimulated with platelet-derived growth factor and HL-60 cells induced to differentiate into macrophages or neutrophils to study the regulation of prostaglandin and leukotriene synthesis. Addition of platelet-derived growth factor to quiescent 3T3 fibroblasts led within 4 h to a dramatic and preferential increase in prostacyclin synthesis from endoperoxide prostaglandin H2, and microsomal assays showed a strong platelet-derived growth factor-dependent increase in the maximal velocities (Vmax) of both prostaglandin H synthase and prostacyclin synthase. In contrast, addition of phorbol ester to HL-60 cells to induce differentiation into macrophages led within 4 h to a strong and preferential increase in thromboxane synthesis from prostaglandin H2, and microsomal assays disclosed a major rise in Vmax for both prostaglandin H synthase and thromboxane synthase. No comparable changes occurred in HL-60 cells that were differentiating into neutrophils, though upregulation of 5-lipoxygenase pathway enzymes occurred in both differentiation systems. Actinomycin D and cycloheximide prevented the appearance of all of these enzymes of eicosanoid synthesis in all three model systems. Thus, the distinctive patterns of eicosanoid synthesis that are seen in replicating fibroblasts and in differentiating macrophages and neutrophils appear to depend on a coordinate, selective upregulation of several enzymes of eicosanoid biosynthesis that is specific for each cell system.

Animals↗
PubMed1988

[Joseph O'Dwyer--a pioneer in endotracheal intubation and pressure respiration].

The oro- and nasotracheal intubation has been developed into one of the most important techniques in anaesthesiology. Originally, intubations were carried out for overcoming acute diphteric airway obstruction in children. As late as the end of the 19 century, the only life saving chance was to perform tracheotomy. Although the technique for this operation at that time was well developed, it was very often impossible to save the life of those moribund patients. The famous American paediatrician Joseph O'Dwyer re-initiated the technique of intubation and his excellent results became great success and promoted world-wide use, although it was a well-known procedure at that time. His intubation method - also called the O'Dwyer-Method-was first published in the N. Y. Medical Journal as "Intubation of the Larynx" 100 years ago. Working together with the surgeon George Fell, O'Dwyer designed an apparatus, for artificial respiration. As Fell-O'Dwyer Apparatus it was widely used in cases of asphyxia, - even in those caused by overdosage of anaesthetics. Further developments of the apparatus permitted positive pressure ventilation and the combination with a funnel for narcotics increased the repertory of anaesthesiological possibilities.

History, 19th Century↗
PubMed1988

Effects of nicotine on eicosanoid synthesis of differentiating human promyelocytic leukemia cells.

We studied the conversion of arachidonic acid or prostaglandin H2 into eicosanoids in promyelocytic leukemia cells (HL-60) that were differentiating into macrophages or neutrophils. Our results indicate that several enzymes of eicosanoid synthesis are coordinately and differentially upregulated early in the neutrophil and macrophage differentiation pathways. They also provide evidence for a preferential upregulation of thromboxane synthase in the macrophage differentiation pathway that contrasts with a preferential upregulation of enzymes of the 5-lipoxygenase pathway during neutrophil differentiation. Nicotine at 100 nM selectively inhibited the formation of thromboxane in HL-60 cells induced to differentiate into macrophages. Nicotine therefore alters the pattern of activity of the eicosanoid-synthesizing enzymes in HL-60 cells undergoing macrophage differentiation.

Arachidonic Acid↗
PubMed1987

sn-1,2-Diacylglycerols and phorbol diesters stimulate thromboxane synthesis by de novo synthesis of prostaglandin H synthase in human promyelocytic leukemia cells.

We studied the regulation of thromboxane (TX) synthesis in promyelocytic leukemia cells during macrophage differentiation. Cells treated with 12-O-tetradecanoylphorbol-13-acetate (TPA) showed rates of TXB2 synthesis from exogenous arachidonic acid that exceeded that of control cells by a factor of up to 81. Cells treated with sn-1,2-dioctanoylglycerol (diC8) showed similarly high TXB2 synthesis rates when diC8 was added concomitantly with a subthreshold concentration of TPA or when given in multiple doses. These activities depended on de novo synthesis of prostaglandin H (PGH) synthase because: microsomal PGH synthase activity showed large increases in Vmax values, and mass measurements of PGH synthase revealed the presence of PGH synthase in differentiating cells whereas the enzyme was undetectable in control cells. These results indicate that macrophage differentiation is associated with stimulation of TXB2 synthesis that requires both activation of protein kinase C and de novo synthesis of PGH synthase.

Arachidonic Acid↗
PubMed1986

Low density lipoprotein receptor-dependent prostaglandin synthesis in Swiss 3T3 cells stimulated by platelet-derived growth factor.

We studied the effects of human plasma lipoproteins on the synthesis of prostaglandin (PG) E2 in Swiss 3T3 mouse fibroblasts. Quiescent cells, maintained in medium deficient in both platelet-derived growth factor (PDGF) and lipoproteins, synthesized less than 8 ng of PGE2 per 10(6) cells per 22 hr, and this rate did not change in response to the addition of lipoproteins. In contrast, PDGF-stimulated cells, incubated in medium deficient in lipoproteins, synthesized 45-110 ng of PGE2 per 10(6) cells during the same period of time, and this rate increased 2- to 5-fold in the presence of added low density lipoproteins (LDL). This stimulatory effect of LDL seemed to depend on LDL receptor-mediated binding, uptake, and degradation of the lipoproteins because: both LDL and very low density lipoproteins were active, whereas high density lipoproteins were not; low concentrations of LDL were effective; the effect of native LDL was blocked by acetylation of the LDL; PDGF increased both the expression of LDL receptors and the cellular uptake of LDL; chloroquine blocked the effect of LDL but not that of exogenous arachidonic acid. These results provide evidence that the LDL pathway is critically linked to PG synthesis in PDGF-stimulated cells.

Acetylation↗
PubMed1986

[The history of tracheotomy. I].

Tracheotomy is one of the oldest operations. Indications for and methods of the operative technique are reported already from the ancient times. The following outline - subdivided in three parts - tries to give a comprehensive survey of the development of tracheotomy throughout the centuries. The first part is concerned with the role of tracheotomy in antiquity, in Greek and Roman medicine and in the medicine of the Arabians at the turn of the millennium according to our time. The first tracheotomy is said to have been performed by Asklepiades of Bythinien, who lived in Rome during the last century before the Christian era. The question whether tracheotomy would be of use or not was highly controversal in the following centuries. There were advocates of the operation (for example Antyllus, Paulus von Aegina), but there were strict antagonists, too (for example Aretaeus). In Arabian medicine finally, tracheotomy had an important rank in theory, but probably it had never been performed in humans. The second part of this paper is occupied with the establishment of tracheotomy in the medicine of the European middle ages. Despite many ethical reservations, it became generally accepted as the last live-saving method in certain syndromes. Protagonists of the method included Ambroise Paré, Thomas Fienus, Hieronymus Fabricius ab Aquapendente, Julius Casserius, and Johannes Scultetus. A new method of performing tracheotomy, the opening of the trachea with the use of a trocar, was first described by Sanctorius Sanctorius (1561-1636). The third part of this outline describes the development of the method of tracheotomy in the last 400 years.(ABSTRACT TRUNCATED AT 250 WORDS)

Ethics, Medical↗