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Biomedical subjects

H Jakob

Publications and source records attributed to H Jakob.

At least 91 records · Page 5Linked to original sources
PubMed1986

Prenatal developmental disturbances in the limbic allocortex in schizophrenics.

Sixty-four autopsied brains of schizophrenic patients were neuropathologically examined and compared with 10 brains of non-schizophrenic controls. Clinical diagnoses were established retrospectively according to the Research Diagnostic Criteria and the International Classification of Diseases. We found: brains without deviations of the sulcogyral pattern of the temporal lobe or abnormal gross configuration (n = 22); brains with abnormal sulcogyral pattern of the temporal lobe or abnormal gross configuration (n = 42): with definite cytoarchitectonic abnormalities of the rostral entorhinal region in the parahippocampal gyrus and, in 16 cases only, in the ventral insular cortex (n = 20); with equivocal changes of the cytoarchitecture in these two regions (n = 22). Generally, these anatomical abnormalities were asymmetric. The histological findings in the two limbic regions consisted mainly of poorly developed structure in the upper layers, with a heterotopic displacement of single groups of nerve cells in the entorhinal region. Particularly, the disturbed structure of the second layer Pre-alpha in medial and central fields of the entorhinal region, situated in the parahippocampal gyrus (group 2a), suggests a disturbance of neuronal migration in a later phase of cortical development.

Adult↗
PubMed1985

Single channel currents in mouse embryonal multipotential carcinoma cells.

Electrical membrane properties of embryonal non-differentiated carcinoma cells which have been extensively used for the study of early mammalian embryogenesis were investigated by using patch clamp techniques. These multipotential cells were found to contain a restricted repertoire of a small number of ionic channels on the whole cell membrane. The most abundant type was a voltage- and calcium-activated potassium channel with characteristics similar to those described in fully differentiated cells.

Animals↗
PubMed1984

Combined application of heterologous collagen and fibrin sealant for liver injuries.

Hemostasis in complex liver injuries remains a problem despite improvements in operative techniques including debridement, suturing or packing. To evaluate fibrin sealant (FS), a new biodegradable hemostatic agent in combination with porcine collagen for sealing of liver injuries, three series of experiments were performed in 132 rats. In series I, 18 rats had a 10-mm in diameter and 2-mm in depth punch defect to the left lateral lobe. In the FS group (n = 9), bleeding was treated by insertion of an FS-soaked piece of collagen of equal size which was firmly attached to a plastic disk with wire anchor. In the control group (n = 9), collagen alone was inserted. Fifteen minutes after the insertion the lobe was excised and pull-off experiments were performed with simultaneous script chart recording. There was a highly significant difference in the adhesion to the liver surface (85.6 +/- 7.1 in the FS group versus 24.8 +/- 2.6 g/cm2 in the control group, P less than 0.001). In series II, 42 anticoagulated rats (Coumadin, PT 27.5% +/- 1.3) with lobectomy or liver rupture were placed in three groups (n = 14). Group I was treated with FS, group II with FS and collagen, and group III with catgut sutures which served as controls. Fourteen days later 12 rats of group I, 13 of group II, and 7 of group III were alive yielding 85.7, 92.8, and 50% overall survival rates, P less than 0.05 groups I and II versus group III. In series III, 72 non-anticoagulated rats were treated identically to series II and examined morphologically at 1, 7, 28, and 56 days.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1984

Stem cells and embryo-derived cell lines: tools for study of gene expression.

Embryonal carcinoma (EC) cells obtained either from teratocarcinomas or directly from in vitro cultures of mouse embryos (EK) can be used as models for the early stages of normal mammalian development. A few known examples of experimental designs with such cells are reviewed: aggregates with normal embryos, promotion of parthenogenetic development by injection of EK cells into blastocysts, EK cells homozygous for a lethal gene, timing of expression in differentiating EC cells of a tissue-specific gene product, and X chromosome inactivation.

Animals↗
PubMed1984

Use of fibrin sealant for reinforcing arterial anastomoses.

Despite improvements in needles, sutures, and technique, hemorrhage remains a problem in cardiovascular surgery. In this study conventional vascular suture lines and suture lines reinforced with fibrin sealant are compared for blood loss and burst strength. Bilateral femoral arteries in 20 dogs were divided at 50% of their circumference and repaired with six 6-0 polypropylene sutures. Ten animals were systemically heparinized (3 mg/kg), and 10 were not on anticoagulants. The right femoral artery anastomosis was treated with fibrin sealant in all animals, and the left suture line served as the control. Three minutes after initiation of the sealing procedure, blood flow was reinstituted in both femoral arteries. After 3 minutes a significant difference in blood loss between the conventional suture technique and fibrin-reinforced anastomoses was noted in both heparinized (12.1 +/- 2.79 vs. 0.13 +/- 0.06 ml/min; p less than 0.01) and nonheparinized dogs (8.45 +/- 1.37 vs. 0.20 +/- 0.08 ml/min; p less than 0.001). After 30 minutes volume inflow and pressure catheters were inserted into snared compartments encompassing the femoral artery anastomosis. Continuous pressure recordings during volume loading with normal saline solution demonstrated increased bursting pressures of the fibrin-sealed suture lines in both the heparinized (317.5 +/- 13.18 vs. 135 +/- 23.17 mm Hg; p less than 0.001) and nonheparinized animals (474.5 +/- 26.82 vs. 311 +/- 29.31 mm Hg; p less than 0.001). Histologic examination revealed no fibrosis or foreign body reaction and complete resorption of the fibrin sealant within 3 weeks. Fibrin sealant, a powerful hemostatic agent produced from human donors not suffering from hepatitis, decreases blood loss and strengthens suture lines.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1984

Evaluation of fibrin sealing for cardiovascular surgery.

Hemorrhage remains a problem in patients undergoing cardiovascular surgery. To evaluate fibrin sealant, a completely biodegradable hemostatic agent, three series of experiments were performed in mongrel dogs. In series I, 18 dogs had a 7 cm interposition of knitted Dacron (water porosity 1500 ml/min/cm2) in the descending aorta. In group A, all prostheses were treated with fibrin sealant and in group B by blood preclotting. Measurements of blood loss demonstrated 1.29 +/- 0.26 ml/min in group A as compared with 30.16 +/- 2.85 ml/min in group B (p less than .001). In series II, six dogs of each group were compared for thrombogenicity and platelet survival by using indium-111-labeled autologous platelets. According to Goldman et al., the thrombogenicity index was calculated. The mean thrombogenicity index for group A was 0.23 +/- 0.02 in contrast to 0.33 +/- 0.05 for group B (p greater than .05). Mean platelet survival was 5.59 +/- 0.23 days in group A in contrast to 5.34 +/- 0.05 days in group B (p greater than .05). In series III, the gluing potential was investigated by creating four types of injuries: four dogs had an aortic stab wound 3 to 5 mm, six dogs received a 10 to 15 mm stab wound to the left ventricle, seven dogs had a 3 cm laceration of the left atrial appendage, and four dogs had bilateral division of their carotid arteries. Wounds of the aorta and left atrial appendage were treated by partial clamping and the sole use of fibrin sealant, the carotid arteries were repaired by four simple sutures and fibrin sealant, and the left ventricular stab wounds were treated by the combined use of heterologous collagen and fibrin sealant without suture.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1983

Two specific markers for neural differentiation of embryonal carcinoma cells.

Two multipotential embryonal carcinoma (EC) cell lines, 1003 and 1009, can be induced to form preferentially neural derivatives in vitro. Synthesis of specific proteins during neural differentiation was followed by two-dimensional gel electrophoresis. The comparison of protein patterns obtained with neural and non-neural derivatives of these EC cell lines indicates that two changes are specific for the neural pathway: (i) the appearance of a new beta-tubulin isoform and (ii) the accumulation of the brain isozyme of creatine phosphokinase already present in small amounts in EC stem cells. These changes were found to take place early in the course of differentiation and to occur even when neurite outgrowth was prevented.

Animals↗
PubMed1983

[Alkali resistance changes from use of water-in-oil- and oil-in-water emulsions].

Metal workers who up to 4 h prior to the alkali resistance (AR) test had applied different O/W-emulsions revealed a better mean AR on the forearms than those who had used W/O-emulsions or no protective skin ointments at all. Similar test results were achieved in 9 metal workers tested in a right-left comparison under standardized external conditions as in more than 300 workers of various industries. By a right-left comparison of an O/W- and W/O-emulsion with 14 students it was shown that all subjects with a low pre-test AR revealed an increased AR after the application of the ointment. Proved differences in AR-reactivity related to occupation and skin constitution of the subject tested are considered to be due to differences in the hydration rate of the horny layer.

Alkalies↗
PubMed1982

In vitro differentiation of mouse teratocarcinoma cells monitored by intermediate filament expression.

Teratocarcinoma differentiation has been studied using sera specific for each of the five intermediate filament (IF) classes. These antibodies distinguish cells of epithelial, muscle, neural, astrocytic, and mesenchymal origin. In embryoid bodies, derived from embryo transplants and obtained in the ascitic fluid by transplantation of teratocarcinoma, the cells of the inner cellular mass did not express any of these intermediate filament types while the outer cells expressed cytokeratin. Intermediate filament expression in the embryoid body thus appears analogous to that in the blastocyst and differs from that in embryonal carcinoma (EC) lines. Twelve EC lines have now been shown to express vimentin although in some EC lines not all cells express vimentin. Other established permanent differentiated cell lines, derived from EC lines in vitro or from tumors in vivo, have been characterized with respect to the type of IF they contain. The distribution of different IF types has been examined in EC cells induced to differentiate by addition of retinoic acid. The proportion of cells expressing each type of intermediate filament appears to depend on the EC cell line used, on the inducing agent, and on the length of treatment. Thus, for instance, F9 cells express cytokeratin, PCC3 derivatives express vimentin, many 1009 derivatives express either glial fibrillar acidic protein (GFA) or neurofilament proteins. Overall the results obtained are in excellent agreement with emerging principles of intermediate filament expression during embryonic differentiation, thus emphasizing the potential use of the various EC lines to study differentiation in culture.

Animals↗
PubMed1982

Collagen synthesis in mouse embryonal carcinoma cells: effect of retinoic acid.

In five lines of mouse embryonal carcinoma cells, PCC3/A1, PCC4, PCC4/Aza-R1, and F9, collagen synthesis was examined by immunofluorescence reaction using specific antibodies directed against collagen. All the embryonal carcinoma cell lines showed type IV collagen, and PCC7-S/Aza-R1 revealed the additional presence of type III collagen. When the F9 and PCC3/A1 EC cells were treated with retinoic acid and dibutyryl-cAMP, they differentiated into morphologically different cellular types. These cellular types showed new types of collagen. Thus, in treated F9 cells, type I, type III, and type V collagen were detected and in treated PCC3/A1 cells, type III and type V collagen were detected. In two established cellular strains, PYS-2 corresponding to parietal endoderm and 3TDM-1 corresponding to trophoblastoma, collagen was identified by immunological reaction and electrophoretic mobility. The trophoblastoma cell line was characterized by the production of type I, type III, and type IV collagen, whereas endodermal PYS-2 revealed type IV collagen.

Animals↗
PubMed1981

Differentiation of a teratocarcinoma line: preferential development of cholinergic neurons.

A line of embryonal carcinoma cells, PCC7-S, established in vitro from a spontaneous testicular teratocarcinoma, has been studied. Upon removing the cells from a low density monolayer culture system and permitting the cells to form aggregates in suspension, we observed a change of several physical and biochemical parameters: (a) reduction in average cell volume, (b) blockage and accumulation of cells in G1, (c) rise in secreted protease activity, (d) rise in acetylcholinesterase and choline acetyltransferase activities, and (e) disappearance of embryonic antigen F9. Although PCC7 aggregates did not undergo substantial morphological changes while suspended, when aggregates 4 or more days old were allowed to attach to plastic tissue culture dishes, substantial neurite outgrowth occurred over the next 1-3 d. This process was markedly enhanced by the addition to the growth medium of carboxymethylcellulose and inhibitors of DNA synthesis. Transmission electron microscopy disclosed a neurite ultrastructure consistent with that of neuronal processes. A veratridine-stimulated, tetrodotoxin-blocked sodium influx of 100 nmol/min per mg protein was also observed in these differentiated surface cultures. This cell line is discussed in terms of its utility for the study of early events leading to a commitment to cellular differentiation, as well as for the investigation of terminal differentiation to cholinergic neurons.

Acetylcholinesterase↗
PubMed1980

Bone-forming cell line derived from embryonal carcinoma cells.

The use of established cell lines of various types has provided information on the properties of certain stem cells and on the conditions of their differentiation. No bone-forming cell line has so far been described. We report here the isolation, from in vitro differentiating teratocarcinoma cells, of a line which, on subcutaneous injection into syngeneic mice, gives rise to ossicles. The appearance of ossicles is preceded by the formation of a cartilaginous matrix, thus reproducing what has been described as endochondral differentiation. The ossicles obtained are rapidly colonized by host marrow, are non-malignant and stop growing 2 weeks after injection of the cells. In certain conditions, however, osteosarcomas, chondroosteosarcomas and fibrosarcomas can be obtained. From these tumours, cell lines have been isolated which retain in vitro the properties of the cells found in the tumour.

Animals↗
PubMed1979

Tropomyosin synthesis accompanies formation of actin filaments in embryonal carcinoma cells induced to differentiate by hexamethylene bisacetamide.

Hexamethylene bisacetamide (HMBA) induces in vitro the cytodifferentiation of PCC3/A/1 mouse embryonal carcinoma (EC) cells. In EC cells, actin is associated with surface structures but microfilament bundles are not seen. After 2 days of HMBA treatment, rounded EC cells are converted to flat adhesive ones with a developed cytoskeleton containing actin and tropomyosin. The ratio of actin to total proteins is constant in EC cells and their HMBA derivatives; but a striking difference is observed for one of the newly synthesized proteins (Mr 34,000) identified as tropomyosin. Synthesis of tropomyosin is followed by its association with actin microfilament bundles, as revealed by indirect immunofluorescence microscopy with specific antibodies.

Acetamides↗
PubMed1979

Junctional modulation in mouse embryonal carcinoma cells by Fab fragments of rabbit anti-embryonal carcinoma cell serum.

Mouse embryonal carcinoma PCC4 cells are connected by extensive gap and tight junctions. When the cells are incubated in a medium containing Fab fragments against embryonal carcinoma F9 cells, they round up and a process of junctional removal is initiated. In particular, gap junctions are internalized and after 30 hr of incubation with the anti-F9 Fab fragments both tight and gap junctions are no longer present at the cell surface; however, the cells are still in contact by means of small attachment sites.

Animals↗