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Biomedical subjects

E Nagel

Publications and source records attributed to E Nagel.

At least 109 records · Page 6Linked to original sources
PubMed1992

[Changes in liver function and morphology after various portocaval bypass operations].

Using an experimental animal model consequences of operatively changed modes of liver perfusion on hepatic function could be demonstrated. Three groups of 5 animals each (swine) had the following operations: Group I received a portocaval shunt. In group II in addition to the portocaval shunt a vein graft was interposed between the vena cava and the portal vein. In group III an arterialization of this graft was performed in addition to the two operations mentioned above. Follow-up at defined time intervals included clinical, laboratory and histological data. It could be demonstrated that animals in group II and III showed normal parameters as far as behavior and controlled lab data are concerned. Animals of group I had significantly poorer results in all tests. In this study we found that direct portal perfusion was not necessary for a normal liver function and could be fully compensated both by caval venous blood and by arterialized caval venous blood.

Animals↗
PubMed1992

Antigen binding properties of highly purified bispecific antibodies.

A panel of three bispecific monoclonal antibodies (bsMAbs) binding to follitropin (FSH) and to beta-galactosidase have been prepared by fusion of hybridoma cell lines resistant to oubain and neomycin. One of these bispecific antibodies contains heavy chains of the same IgG subclass, and two are composed of heavy chains of different IgG subclasses. We have investigated methods for the purification of bispecific antibodies from hybrid hybridoma supernatant fluids grown in serum-free medium. Following ammonium sulfate precipitation, bispecific antibodies can be purified in a single step by mixed mode ion-exchange HPLC on Bakerbond Abx columns. In one case, three species were resolved by ion-exchange HPLC and functional analysis showed that two peaks contained parental antibodies, and the third contained the bispecific. Ion-exchange HPLC purification of serum-free preparations from two other hybrid hybridomas resolved seven protein-containing peaks, only one of which was active in a bispecific ELISA. The equilibrium affinity constants for each of the parental antibodies for both FSH and beta-galactosidase were determined and found to be similar to those of the purified bsMAbs. Further, the association of FSH to one binding site on a bispecific antibody was shown to have no effect on the equilibrium binding constant for beta-galactosidase binding to the other site. Our results suggest that bsMAbs can be readily purified from hybrid hybridomas by a simple and rapid method, and the binding of antigen to one binding site on a bsMAb is independent of antigen binding to the second site.

Animals↗
PubMed1992

[Measuring retinal vascular diameter using the scanning laser ophthalmoscope and computer. Initial results].

The diameter of the large retinal vessels is an important factor in retinal microcirculation. A system configuration was developed that uses SLO images to measure the diameter of retinal branch vessels off-line. The place for measurement is defined in the image by the investigator, and the diameter is measured automatically. The mean standard deviation of the diameter of arterial vessels was 2.37% and for veins 3.43% by repeat measurement in sequential pictures by optimal scanner settings. The reproduction of vessel diameters was unsatisfactorily for repeat examinations. The course of these results may be changes in the fundus image connected with changes in the position of the scanner-bulbus (e.g., new examination, poor fixation). The scanner-bulbus position is not yet precisely defined and not reproducible enough.

Adult↗
PubMed1992

[Experimental damage of the epithelial layer of the ileum by dietary fats: transmission electron microscopy findings and their comparison with cell pathology in Crohn disease].

Regarding the unknown pathogenesis of Crohn's disease repeatedly the importance of diet has been accentuated. Epidemiological, biochemical and animal experimental results have focused on a possible relationship between the consumption of chemically processed, partial hydrogenated fats and the development of regional enteritis. In this context an experimental animal model in pigs was designed to analyze, whether transmission electron microscopic alterations of ileal mucosa could be induced by forage of chemically processed fats. By creation of a retroperistaltic ileal segment the contact time between chyme and intestinal mucosa was prolonged. Our underlying question was to what extent disorders of the intestinal barrier function could be compared to Crohn's disease. Present study concentrates on the epithelial-cell-layer. It was shown that in comparison to the control animals the lamina epithelialis mucosae of all animals after fat-feeding was characterized by: sublethal lesion of the enterocytes/crypt-epithelial cells (shortening and alteration of the microvilli, degeneration of mitochondria, formation of autophagocytic vacuoles); goblet cell hyperplasia and increased production of mucus; focal appearance of intraepithelial lymphocytes as well as presence of polymorphonuclear granulocytes in the epithelium; widening of the intercellular-space locally up to total loss of the functional structure of the epithelial-cell-layer. In total the picture can be evaluated as an inflammatory process of the ileal mucosa. It can be concluded, that chemically processed fats as used in the described experimental conditions could induce this process. The feature of mucosal damage shows obvious similarities to ultrastructural findings in Crohn's disease if compared.

Animals↗
PubMed1991

[What is the role of nutrition in Crohn disease? A contribution to the importance of dietary therapy in regional enteritis].

The clinical appearance of Crohn's disease (CD) is especially marked by nutritional deficits and insufficiencies. For a long time the goal of nutritional care was reduced to the readjustment of the nutritional status. The development and clinical use of controlled parenteral nutrition (TPN) and enteral nutritive solutions (EN) did not only emphasize this therapeutical issue, but furthermore showed positive effects on the conservative as well as on the surgical treatment concepts. Therefore today artificial nutritional support is a firm part of therapy in acute, active phases or in the contact of surgical management of CD. This is especially valid in children, where complications in general and growth failure in particular can be reduced. EN is the preferred feeding method in most of the cases, due to a lower complication rate and reduced cost when compared to TPN. The question regarding the importance of nutritional support as primary therapy has also been investigated. The results differ extensively, but point towards the conclusion that patients with solitary small bowel disease do profit from this therapeutical concept. Nevertheless it is unclear, how TPN or EN interfere in the pathophysiology or -biochemistry in this process. A question about reduction e.g. of allergic components of daily diet did stimulate new theories regarding the hypothesis of a possible causal relationship between diet and the pathogenesis of CD. Investigations on dietary habits and daily dietary therapy did not reveal an overall accepted dietary guideline. Nevertheless it seems obvious that dietary counselling has a positive effect on the disease process. It does appear, that today in the acute, active phase as well as in the long term management of Crohn's disease nutritional-care is an important therapeutical method.

Crohn Disease↗
PubMed1991

[Diagnosis and classification of tricuspid valve insufficiency with dynamic magnetic resonance tomography: comparison with right ventricular angiography].

To evaluate the diagnostic potential of magnetic resonance imaging (MRI) to diagnose and evaluate tricuspid incompetence (TI), right ventricular angiography (RVA) and MRI were compared in 51 patients. For angiographic semi-quantification a 4-grade modified Sellers classification was used. Several MRI-parameters (jet volume, jet area, number of slices with visible jet, duration of the regurgitation and volume of the right atrium) were examined concerning their validity to evaluate TI and compared to the angiographic data. Limits for MRI jet areas and volumes for each angiographic group were defined to obtain the best agreement with angiographic results. Thirty of 34 patients with angiographically visible TI (sensitivity = 88%) were diagnosed correctly with MRI. The 4 remaining patients also showed a small regurgitant jet which was, however, interpreted as physiologic. One of the 17 patients without angiographic TI was diagnosed as mild TI by MRI (specificity = 94%). MRI classification using jet volume (46/51 = 90% correct classifications) was not significantly better than the easier and faster MRI classification using jet area (43/51 = 84%). The other parameters (number of slices, duration of regurgitation and volume of the right atrium) showed considerable overlap between angiographic groups and did therefore not allow a classification into 4 grades. However, simple classification into hemodynamic relevant and irrelevant TI was possible. Thus MRI is able to diagnose TI with good sensitivity and specificity. Classifications based on jet volume and jet area showed good agreement with angiographic results. However, both parameters depend on the magnet and the pulse sequence used and must therefore be specifically determined for each imaging routine.

Adult↗
PubMed1989

Comparison of prehospital conventional and simultaneous compression-ventilation cardiopulmonary resuscitation.

Nine hundred ninety-four patients were enrolled in a field trial in which ambulance crews were randomly assigned to use simultaneous compression-ventilation (SC-V) CPR or conventional CPR procedures in the prehospital setting. Survival to hospital admission and to discharge was superior in the conventional CPR group vs. the experimental group (p less than .01). In a subset of adult cases whose causes of arrest were nontraumatic, survivor rates still favored the conventional CPR group: 33.5% of 337 vs. 22.5% of 365 (p less than .001). In limited cases where cardiac arrest was due to other heart disease, was vascular in origin or secondary to other natural diseases or from hypertensive cardiovascular disease, or when ECG on arrival was an agonal rhythm, survival was better (but not statistically significantly) in the experimental group. There were no statistically significant differences in the Glasgow coma scores between surviving patients in either group at 24 h post-hospital admission or discharge. It is concluded that survival in the SC-V CPR group was lower, likely reflecting a deleterious effect of the experimental technique of resuscitation. Also noted was that 14% of the control patients and 6% of the experimental patients survived with manual CPR alone.

Adolescent↗
PubMed1988

[Pathogenesis of Crohn's disease. Evaluation criteria for an animal model].

The origin of Crohn's disease is controverted. Experimental animal studies have not thus far supported a specific pathogenetic factor, a situation ascribed to the fact that the standard requirements of an "ideal" animal model are unsuited to diseases with a multifactorial pathogenesis such as Crohn's disease. In a new experimental animal model the hypothesis of a causal relationship between chemically processed dietary fats and the development of Crohn's disease was studied in 32 pigs. One finding was that experimental animals showed early morphologic lesions of the mucosa as specific to regional enteritis. The primary changes in the mucosa are thought to play a fundamental role in the pathogenesis of the disease. The model opens up new perspectives for planning, management and evaluation of experimental animal models in studying further aspects of etiology in Crohn's disease.

Animals↗
PubMed1988

Sudden cardiac arrest in Israel: factors associated with successful resuscitation.

Out-of-hospital cardiac arrests were studied in Israel from 1984 to 1985. More than 3,500 patients in cardiac arrest received paramedic care. Eighty-three percent of cases were caused by underlying heart disease. Overall, 17% of patients with arrest caused by heart disease were admitted and 7% were discharged from the hospital. There was a wide variation in the percent discharged among the 15 paramedic service areas, ranging from 0% to 13%. Factors associated with successful resuscitation included witnessed collapse, rhythm of ventricular fibrillation, short interval from collapse to cardiopulmonary resuscitation (CPR) and delivery of advanced cardiac life support, collapse at public location, and bystander initiation of CPR. Improvements in survival are likely to result if CPR is more frequently and promptly initiated and the time to arrival of definitive paramedic care can be improved.

Aged↗
PubMed1983

Hub Group: an innovative approach to group therapy in a short-term inpatient adolescent unit.

Two and one-half years of Hub Group have shown that short-term, ward-based, heterogeneously mixed adolescent groups can work. Backed by a behaviorally based privilege system, Hub Group contracting methods facilitate rapid investment in group therapy, are flexible enough to accommodate change, and provide a meaningful ritual that involves all group members in promoting change for the individual. Hub Group's method of self-rating and rewards promotes objectivity in self-evaluation. The contracts' images are compact, but all encompassing, providing a continuum along which to move in developing greater responsibility and productive functioning for the adolescents. There are distinct advantages and disadvantages to mixed levels of functioning within the same group. The nurturance and tolerance for others fostered by Hub Group is a primary advantage. Despite the obvious disadvantages of rapid turnover, common issues such as acceptance, attachment, and separation are ever present to be addressed. Leadership must be either supportive or confrontive, but always active in these groups. Hub Groups have shown that with the support and supervision of IDTU's administrative staff, diversely trained staff can comfortably perform multiple roles within the unit and be effective as group leaders.

Acting Out↗
PubMed1983

Comparative study of piroxicam and indomethacin retard in osteoarthritis.

Indomethacin retard and piroxicam were compared in an open, randomized, parallel study in the treatment of osteoarthritis. Improvement of the symptoms of the disease was highly significant for both drugs. There was no statistical difference between the two drugs in terms of efficacy. Number and duration of side effects were significantly lower with piroxicam than with indomethacin retard. Piroxicam was administered once a day. Indomethacin retard was always (43% of the cases) or sometimes (14%) given twice daily.

Anti-Inflammatory Agents↗
PubMed1981

[Comparative study of piroxicam and indomethacin retard in arthroses].

Indomethacin retard and piroxicam (Felden) were compared in an open, randomized parallel study in the treatment of osteoarthritis. Improvement of the symptoms of the disease was highly significant for both drugs. A statistical difference in the efficacy was not proved. Number and duration of the side effects were significantly lower with piroxicam than with indomethacin retard. Piroxicam was only applied once a day. Indomethacin retard was always (43% of the cases) or sometimes (14%) applied twice daily.

Arthritis, Rheumatoid↗
PubMed1977

[Differentiation of lymphocyte populations in the blood of breast-cancer patients].

The number of T lymphocytes has been determined in the peripheral blood of 90 women (65 patients with breast cancer and 25 healthy controls) using a sheep-erythrocyte rosetting technique and a cytochemical method for intracellular localization of a nonspecific acid esterase. Both tests were in agreement in showing a significant depression of T-cell percentage in a group of patients with progressive disseminated breast cancer under hormonal and chemotherapeutic treatment. After radiotherapy a fall in T cells was observed only with the rosetting method. Possible reasons for this phenomenon are discussed.

Animals↗