Search PubMed⌕ Search

Biomedical subjects

C Ernst

Publications and source records attributed to C Ernst.

At least 55 records · Page 3Linked to original sources

Ventilation-perfusion relationships in isolated blood-free perfused rabbit lungs.

The multiple inert gas elimination technique (MIGET) was applied to blood-free perfused isolated rabbit lungs. Commonly accepted criteria for reliability of the method were found to be fulfilled in this model. Ventilation-perfusion (VA/Q) distributions in isolated control lungs corresponded to those repeatedly detected under physiological conditions. In particular, a narrow unimodal dispersion of perfusate flow was observed: perfusion of low-VA/Q areas ranged below 1% and shunt flow approximately 2-3%; perfusion of high-VA/Q regions was not detected. Gas flow was characterized by narrow dispersion in the midrange-VA/Q areas. Application of a low level of PEEP (1 cmH2O) reduced shunt flow to less than 1%, and low-VA/Q areas were no longer noted. By using this PEEP-level, stable gas exchange conditions were maintained for greater than 5 h of extracorporeal perfusion. Graded embolization with small air bubbles caused a typical rightward shift (to higher VA/Q ratios) of mean ventilation, associated with the appearance of high-VA/Q regions and an increase in dead space ventilation. Mean perfusion was shifted leftward, and shunt flow was approximately doubled. Whole lung lavage with saline for washout of surfactant evoked a progressive manifold increase in shunt flow, accompanied by a moderate rise of perfusate flow to low-VA/Q areas. We conclude that the MIGET can be applied to isolated blood-free perfused rabbit lungs for assessment of gas exchange and that typical patterns of VA/Q mismatch are reproduced in this model.

Animals↗

[How can one achieve compliance?--On the after-care of psychiatric patients after clinic discharge].

For 384 of 558 hospitalized psychiatric patients who were discharged within six months and for whom it was possible to plan aftercare, compliance was controlled by a phone call three months after discharge at the institution or practice to which the patient had been directed. Eighty percent of the ambulatory patients complied (schizophrenic patients: 84%). After three months 70 percent of the compliers still were in treatment. The hospital's arranging an appointment for the patient had the strongest influence on compliance. The success of this strategy is confirmed by the literature.

Aftercare↗

[The status of Italian psychiatric reform: the example of Lombardy in comparison with Switzerland].

In Italy, the worldwide reduction in numbers of psychiatric beds since the fifties had led already by 1971 to a much lower per capita rate of beds than in most European countries. In Northern Italy the psychiatric reform of 1979 speeded up the ongoing reduction of beds, ameliorated conditions for hospitalized patients and built up ambulatory care. A comparison with three Swiss cantons shows that, in Lombardy, the largest and economically most developed Italian Region, the rate of patient contacts with outpatient services has probably reached or surpassed the level found in Switzerland. Contacts by home visits are much more frequent than in Switzerland. The number of psychiatric beds per 1,000 inhabitants is 0.7 in Lombardy and thus has been reduced to one third the Swiss bed-ratio. Comparisons of Italian with Dutch and Danish psychiatric register data show that the Italian psychiatric service as a whole reaches a considerably smaller segment of the severely disordered patients. The Region of Lombardy has recently been trying to increase the psychiatric bed-ratio by agreements with private hospitals. The shortage of beds is not compensated by the ambulatory services and is leading to increasing stress for the families of the severely disordered.

Bed Occupancy↗

Neutrophil passage through isolated perfused rabbit lungs.

Kinetics of polymorphonuclear leukocyte (PMN) lung passage were investigated in ex vivo isolated and ventilated left rabbit lungs, perfused with buffer solution at physiological flow rate. 111In-labeled PMNs of rabbit or human origin were injected into the pulmonary artery, and the first fraction of PMNs that rapidly passed the lung together with coinjected erythrocytes, was collected separately for external radioactivity counting. Washout of initially retained PMNs from the lung was monitored by use of a sodium-iodide detector. Recirculation of cells was avoided by insertion of a filter in the perfusion circuit. A fraction of 16.6 +/- 1.3% of rabbit PMNs rapidly passed the lung vasculature, followed by an exponential washout of initially retained PMNs [half-time (t50) of lung transit 8.1 +/- 0.6 min]. Slightly higher t50 (12.2 +/- 1.0 min) was obtained upon use of human PMNs. Reduction in flow by 50% caused a marked prolongation of PMN transit (t50 = 27.8 +/- 5.1 min), whereas increase in flow to 150% only insignificantly decreased t50. Rise in pulmonary venous pressure to 5 and 8 mmHg caused retardation of PMN lung transit (t50 = 15.3 +/- 0.6 and 31.6 +/- 3.6 min). Preincubation of PMNs with 2 ng/ml endotoxin for 1 h induced marked delay in PMN washout (t50 = 26.1 +/- 2.8 min). In conclusion, single-pass PMN kinetics in isolated lungs correspond to in vivo studies previously reported, thus allowing elucidation of PMN-endothelial interactions in an intact lung vasculature under standardized conditions.

Animals↗

Polyethylene failure of metal-backed patellar components. 111 AGC total knees followed for 7-22 months.

In a series of 111 AGC total knee arthroplasties, eight failures of the polyethylene part of the metal-backed patellar component were seen after a period of 7-22 months. All of these patients experienced a characteristic grating sound as the knee was bent, and skyline radiographs revealed direct metal-on-metal contact. At revision, fracture and separation of the polyethylene part were found together with an extensive, black, thickened synovium and abrasive wear of the naked metal backing of the patellar component. The cemented metal backings were all solidly anchored in the patella. Based on this high failure rate, we have abandoned the metal-backed patellar component in favor of an all-polyethylene component.

Aged↗

Inhibition of metastases of a human melanoma xenograft by monoclonal antibody to the GD2/GD3 gangliosides.

A human melanoma variant cell line was obtained from a lung metastasis that arose spontaneously after we inoculated melanoma cells sc into a nude mouse. In this model, IgG2a monoclonal antibody (MAb) ME 36.1 defining the GD2/GD3 gangliosides inhibited melanoma growth at the primary site and metastatic spread of the cells, whereas an IgG1 variant of MAb ME 36.1 inhibited lung metastasis formation only. Possible mechanisms of antitumor effects of MAb ME 36.1 are discussed.

Animals↗

Are early childhood experiences overrated? A reassessment of maternal deprivation.

The opinion that early maternal deprivation (absence of mother, lack of stimulation, multiple caregivers) results in lasting damage to intellectual and emotional development is generally accepted. In a real-time longitudinal study 137 children, part of a representative sample of Kt. Zürich (Switzerland) who spent the first years in residential nurseries, were investigated at age 12.6 +/- 8 months and again at age 14 years. In IQ and education this group at follow-up was not different from the general population. The children were no less popular than a control group of classmates. There were, however, among them two to three times more psychiatric cases than among a Swiss comparison group. Behavioral and emotional disorders were not connected with status at first examination or variables of the early environment, but with psychosocial risk factors in the environment the children lived in after leaving the nurseries: parental discord, divorce, psychosocial disorder in parents, presence of step family, abuse. This finding is confirmed by other prospective and retrospective studies. Early deprivation is almost always an indicator that an unfavorable situation will continue throughout childhood. If, on the other hand, the environment changes completely, as it does after adoption, early deprivation by itself does not appear as a risk factor. The role of the mother-child relationship and of early influences in general on personality ought to be reconsidered.

Adolescent↗

Cell- and tissue-specific expression of a 34,000-molecular-weight peptide growth factor in humans.

A 34,000-dalton peptide growth factor that we originally identified in human placental trophoblasts and in certain carcinomas was shown to be expressed in several normal human tissues. A highly specific antibody to the trophoblast-derived growth factor was used in an immunoperoxidase staining technique to identify the immunoreactive peptide in tissue sections. Immunoreactivity was seen in the adrenal cortex, Leydig cells of the testes, and follicular cells of the thyroid. In addition, strong staining was seen in the ducts and terminal ductules of the pancreas, in glandular epithelium of the prostate, in the chief cells of the stomach, and in the columnar epithelium of the trachea and bronchus of the lung. Certain tissues were negative for the peptide, including the adrenal medulla, liver, esophagus, small intestine, colon, bladder, lymph node, spleen, bone marrow, and thymus. Thus, the expression of the peptide depends on cell lineage and the state of differentiation; tissues of hematopoietic lineage are devoid of the 34,000-dalton peptide, whereas some of the major hormone-secreting tissues that are under pituitary control show the highest immunoreactivity.

Adult↗

Differential influence of calcium channel-blockers on prostanoid generation and thromboxane-mediated vasoconstriction in rabbit lungs.

In blood-free perfused and ventilated rabbit lungs, the influence of calcium channel-blockers on pulmonary prostanoid generation and thromboxane-mediated vasoconstriction was investigated. The specific pathways of arachidonic acid (AA) metabolism were stimulated by repetitive pulmonary artery injection of the calcium-ionophore A 23187, which induces the liberation of endogenous AA, or by repetitive application of exogenous AA. In control lungs, both stimuli provoked reproducible phasic vascular pressor responses, accompanied by the release of thromboxane A2 and prostaglandin I2 into the perfusion fluid. Repeated stimulus application in the presence of increasing concentrations of different calcium antagonists showed a dose-dependent inhibition of the pressor responses by all agents. The rank order of potency was nimodipin greater than LU-40883 (verapamil derivative) greater than diltiazem and D-888 (verapamil derivative) greater than verapamil for the ionophore-induced pressure increase, whereas diltiazem was nearly ineffective in the presence of exogenously applied AA. The prostanoid release after application of A 23187 was influenced differentially by the calcium channel-blockers. It was not affected by nimodipin and verapamil, it was slightly depressed by the verapamil derivatives D-888 and LU-40883 and it was dose-dependently and in higher concentrations nearly inhibited completely by diltiazem. We conclude that the thromboxane-mediated pulmonary vasoconstriction is inhibited by different-type calcium channel-blockers with a marked rank order of potency. The prostanoid generation induced by stimulation of the lung vascular AA metabolism is influenced differentially by these agents.

Animals↗

Influence of the thromboxane antagonist BM 13.177 on the arachidonic acid-induced increase in pulmonary vascular resistance and permeability in rabbit lungs.

UNLABELLED: In blood-free perfused isolated rabbit lungs increased availability of free arachidonic acid (AA), whether exogenously applied or released from the endogenous membrane phospholipid pool after different stimuli, causes an acute pulmonary artery pressor response and an increase in vascular permeability. Previous experiments suggested that the vasoconstriction is caused primarily by the cyclooxygenase product thromboxane (Tx) A2, whereas an increase in the capillary filtration coefficient must be ascribed to non-cyclooxygenase products of AA. The influence of BM 13.177, a non-prostanoic antagonist of TxA2- and endoperoxide-effects in platelets, on the AA-induced vascular effects in isolated rabbit lungs was investigated. BM 13.177 dose-dependently inhibited the pressor responses evoked by repetitive direct application of AA (IC50 approximately 10(-6) M) or by repetitive stimulation of endogenous AA-release with the calcium-ionophore A 23187 (IC50 approximately 10(-7) M), with maximum reduction of the pressor responses to less than 15%. The generation of TxA2 and of prostaglandin (PG) I2 evoked by these stimuli was, however, not altered. At a concentration of 10(-5) M BM 13.177 did not influence the capillary filtration coefficient, measured during venous pressure challenge, under baseline conditions and after stimulation with AA in presence of indomethacin. CONCLUSION: BM 13.177 acts as TxA2/endoperoxide antagonist with dose-dependent inhibition of AA-induced vasoconstriction in the pulmonary vascular bed.

6-Ketoprostaglandin F1 alpha↗

Selection of monoclonal antibodies detecting serodiagnostic human tumor markers.

Monoclonal antibodies (MAbs) were selected for specific binding to spent media of cultured tumor cells. Out of more than 12,000 hybridomas screened, 19 were selected in preliminary inhibition assays for secretion of MAbs which detected antigens in cancer patients' sera. Antibody CO 29.11, which was studied in detail, bound to an antigen shed and expressed by adenocarcinoma cells of colon, stomach, pancreas and urinary bladder. CO 29.11 bound to purified sialylated Lewis a (Lea) antigen but to a different epitope and with a higher binding affinity than the MAb CA 19-9. CO 29.11 but not CA 19-9 bound weakly to unsialylated Lea antigen. In double-determinant radioimmunoassay with sera of patients with colorectal carcinoma, CO 29.11 was found to be a more sensitive marker than CA 19-9 for the detection in serum of sialylated Lea antigen.

Antibodies, Monoclonal↗

Shared antigens of human prostate cancer cell lines as defined by monoclonal antibodies.

Eight monoclonal antibodies (MAbs) raised against human prostate cancer cell lines are described. One MAb was derived from the fusion of mouse myeloma P3x63Ag8-653 cells with spleen cells of mice immunized with DU145 prostate cancer cells. The other seven were from the fusion of myeloma lines P3x63Ag8-653 or SP2/0 with spleen cells of mice immunized with PC3, DU145 and 1013L prostate cancer cells. All of the antibodies also reacted with cell lines of other human cancer types, especially carcinomas. Immunoperoxidase staining on fixed tissue revealed strong reactivity only with antibody PrN10. Seven other antibodies seemed to bind to cell surface-associated (glyco)proteins. Antibodies PrL22 and PrO11 showed similar reactivity in radioimmunoassay, and immunoprecipitated a 160 kD molecular weight polypeptide from [125I]lactoperoxidase-labeled cells. Antibodies PrHk an PrQ12 bound to molecules with apparent MW of 115 kD and 100 kD, respectively; antibodies PrM24 and PrP14 revealed a more complex picture in immunoprecipitation of surface-labeled cells.

Antibodies, Monoclonal↗

[Not Available].

Explore the source record for details and available documents.

Death↗