PubMed Health⌕ Search

Biomedical subjects

H Hampl

Publications and source records attributed to H Hampl.

At least 73 records · Page 4Linked to original sources
PubMed1987

Beta 2-microglobulin, different fragments and polymers thereof in synovial amyloid in long-term hemodialysis.

Amyloid deposits of a patient with long-term hemodialysis were immunohistochemically identified as beta 2-microglobulin (beta 2m)-derived. Amyloid proteins were isolated from fibril concentrates from the synovia by HPLC permeation chromatography. Further analysis included dot immunoassay, immunodiffusion, SDS-polyacrylamide gel electrophoresis and Western blotting. Proteins with molecular masses of 8.5, 12, 17 and 24 kDa as well as polymers of higher molecular mass were detected. Neither the 24-kDa dimer nor the higher polymers could be significantly reduced by disulfide reagents. The N-terminal amino-acid sequence analyses of the two major proteins of 12 and 24 kDa showed the same two sequences each: one commencing with position 1 and the other with position 7 of beta 2m. These results suggest that limited proteolysis and polymer formation independent from interchain disulfide bridging, both play a role in the genesis of beta 2m-derived amyloid in the synovia.

Amino Acid Sequence↗
PubMed1985

Studies on circulatory stability during bicarbonate hemodialysis with constant dialysate sodium versus acetate hemodialysis with sequential dialysate sodium.

Eight stable patients on maintenance hemodialysis were studied while undergoing (a) acetate hemodialysis with a sequential dialysate sodium concentration from 147 to 137 mEq/L (SNa-HDA) and (b) bicarbonate hemodialysis with a constant dialysate sodium concentration of 140 mEq/L (HDB). Circulatory behavior was observed during both of these methods, and both were found to allow a high volume removal. However, as a consequence of the high sodium load during SNa-HDA, volume was shifted from the extra- to the intravascular space. This stabilizing effect on the circulation disappeared with the sequential decrease of dialysate sodium concentration (despite a constant plasma sodium concentration (despite a constant plasma sodium concentration of approximately 140 mEq/L), which was concomitant with a significant decline of the mean arterial blood pressure and an inadequate compensation of the metabolic acidosis. In contrast, a better circulatory response to comparable volume removal was found during HDB, expressed by a stable mean arterial blood pressure in the presence of well-balanced arterial acid-base values.

Acetates↗
PubMed1985

Haemodynamic state in severe chronic renal failure. Pathophysiological aspects of cardiovascular function and the importance of bicarbonate dialysis.

Patients with chronic renal failure were investigated, immediately before dialysis and during haemodialysis for central and systemic haemodynamic parameters. The treatment used was changed from acetate to bicarbonate dialysis. Additionally, acid-base values were assessed and continuous long-time electroencephalographic monitoring was performed. As the severity of the cardiac dysfunction is a decided contributory determinant of the quality of dialysis, we have turned our attention to the changes in cardiac and circulatory function during the predialysis phase and the best method of treating them.

Acetates↗
PubMed1984

Characterization of the envelope proteins of pseudorabies virus.

Previously we have reported that among the proteins of purified pseudorabies virions there are four major glycoproteins (T. Ben-Porat and A. S. Kaplan, Virology 41:265-273, 1970). Several minor glycoproteins can also be identified by two-dimensional gel electrophoresis. Removal of the viral envelope with Triton X-100 selectively removes from the virions all of the glycoproteins as well as several non-glycosylated proteins. Sedimentation analysis or chromatography of these proteins reveals that several are complexed with one another, some being covalently linked via disulfide bridges. Analysis of the proteins by immunoprecipitation with monoclonal antibodies reactive with the membrane proteins showed also that three of the four major virus glycoproteins (125K, 74K, and 58K; gIIa, gIIb, and gIIc, respectively) are linked covalently by disulfide bridges. Furthermore, all three share extensive sequence homology as indicated by the identity of their antigenic determinants and by partial peptide mapping; they probably originate from a single protein precursor. The fourth major glycoprotein (98K; gIII) is not complexed to any other protein. Three minor glycoproteins (130K [gI], 98K [gIV], and 62K [gV]), which form a noncovalently linked complex with a 115K nonglycosylated protein, have also been identified. Of the monoclonal antibodies used in this study, only those reactive with the major 98K glycoprotein (gIII) inhibit virus adsorption and neutralize virus infectivity in the absence of complement. However, all react with surface components of the virion, indicating that the proteins with which they react are exposed on the surface of the virions. A nomenclature for the pseudorabies virus glycoproteins is proposed.

Animals↗
PubMed1983

Functions of the major nonstructural DNA binding protein of a herpesvirus (pseudorabies).

Eight mutants of pseudorabies virus belonging to complementation group 3 and situated between 0.14 and 0.18 units on the physical map of the genome were analyzed. All the mutants tested in this respect (seven) recombined with one another, indicating that the mutations were located in different regions of the gene. All mutants were DNA-; the first round, as well as subsequent rounds, of DNA replication was completely blocked at the nonpermissive temperature in the mutant-infected cells. After shift-up from the permissive to the nonpermissive temperature, viral DNA synthesis continued for a short period of time only and viral DNA which had accumulated at the permissive temperature became degraded. Parental viral DNA, however, retained its integrity at the nonpermissive temperature and viral DNA synthesis started immediately after shift-down of the mutant-infected cells from the nonpermissive to the permissive temperature (even in the absence of protein synthesis). All mutants belonging to complementation group 3 tested (5 out of 8) produced a thermolabile nonstructural DNA binding protein (136K). In some of the mutant virus-infected cells this protein failed to migrate to the nucleus. We conclude that the pseudorabies virus mutants in complementation group 3 code for a defective 136K protein and that this protein is not only essential to the process of viral DNA synthesis but also plays a role in the stabilization of progeny DNA (but not of nonreplicating parental DNA) within the infected cells.

DNA Helicases↗
PubMed1983

Electroencephalogram investigations of the disequilibrium syndrome during bicarbonate and acetate dialysis.

Continuous long-time electroencephalographic (EEG) monitoring was performed during acetate and bicarbonate dialysis in 20 patients. Persisting normal basic activity of the EEG without neurological symptoms was found only during the course of bicarbonate dialysis. However, in acetate dialysis, during the decrease of arterial CO2 tension (PaCO2), we registered EEG disturbances with moderate to severe slowing, dysrhythmic activity and high voltage discharges. The decrease in PaCO2 and the deterioration in EEG activity in the patients during acetate dialysis was concomitant with severe neurological alterations, e.g. the typical symptoms of so-called 'disequilibrium' causing a cessation of dialysis in three patients.

Acetates↗
PubMed1983

[Electro-encephalographic study of the disequilibrium syndrome during bicarbonate dialysis and acetate dialysis].

Continuous long-time electroencephalographic (EEG) monitoring was performed during AHD and BHD in 20 patients. Persisting normal basic activity of the EEG without neurological symptoms could be found only during the course of BHD. However, in AHD, during the decrease of arterial CO2 tension (PaCO2) we registered EEG disturbances with moderate to severe slowing down, dysrythmic activity and high voltage discharges. The decrease in PaCO2 and the deterioration in EEG activity in the patients during AHD was concomitant with severe neurological alterations, e.g. the typical symptoms of so-called "disequilibrium" causing a cessation of dialysis in 3 patients.

Acetates↗
PubMed1982

Mouse Elberfeld (ME) virus determines the cell surface alterations when mixedly infecting poliovirus-infected cells.

The surface alterations of HEp-2 cells induced by mixed infection with two different picornaviruses (poliovirus and ME virus) were compared by scanning electron microscopic and transmission electron microscopic studies and by 51Cr-release assay. The contribution of each of the viruses to the resulting surface changes was discernible, as investigations on the chronology of the cytopathic alterations demonstrated that the changes were distinct for either virus. The surface of ME virus-infected cells was characterized by large membranous structures ('sheets' and blebs) representing huge vacuoles. These sheets were not seen in poliovirus-infected cells. Poliovirus induced more prominent cell pycnosis, elongation of filopodia and condensation of collapsed microvilli on the cell surface than ME virus. Mixed infection with these two viruses led to surface alterations typical for ME virus. These ME virus-specific changes occurred irrespective of poliovirus reproduction or its inhibition by guanidine. ME virus-specific alterations also predominated in cytolytic membrane damage as expressed by 51Cr-release from infected cells. 51Cr-release was more pronounced from ME virus than from poliovirus-infected cells, even when ME virus reproduction was suppressed by interfering poliovirus. However, alteration of the internal structures of the infected cells was only dominated by ME virus when the reproduction of poliovirus was suppressed.

Cell Line↗
PubMed1982

Advantages of bicarbonate hemodialysis.

Six patients with frequent episodes of symptomatic hypotension during acetate dialysis were treated with bicarbonate dialysis. In all patients blood pressure, heart rate, and arterial acid-base values were measured every 30 minutes during each of the five treatments with acetate dialysis and bicarbonate dialysis. Hemodynamic parameters were measured invasively in all patients during bicarbonate dialysis and in three of them also during acetate dialysis. Additionally, continuous long-time monitoring with electroencephalography was performed during acetate dialysis and bicarbonate dialysis. During acetate dialysis the patients showed a frequent onset of sudden hypotension and arrhythmia with concomitant symptoms of the so-called disequilibrium syndrome, whereas these symptoms were nonexistent in the same patients during bicarbonate dialysis.

Acetates↗
PubMed1981

Differences in the morphology of herpes simplex virus infected cells. II. Type specific membrane alterations of HSV-1 and HSV-2 infected cells.

The two types of herpes simplex virus (HSV-1, HSV-2) induced significantly different alterations in the morphology and permeability of infected cells. HEp-2 cells infected with HSV-1 (strain THEA) were characterized by the formation of polynuclear syncytia. In contrast, after infection with HSV-2 (strain D316, DD), the cells were rounded up. The HSV-1 strains KOS and LS5039 and the HSV-2 strain 196 induced both types of cytopathic effect. As shown by comparative scanning and transmission electron microscopy newly synthesized virus particles of the various strains of HSV-1 were generally found to be restricted to smooth areas of the cell surface. In these areas the number of microvilli was reduced in comparison to uninfected cells. However, the progeny viruses of the strains of HSV-2 were mainly connected with protrusions of the cell membrane (microvilli and filopodia). The morphological changes in cells infected with either type of HSV were associated with different functional alterations of the cell membrane. The membranes of HEp-w cells became more stable after infection with HSV-1. This is characterized by a reduced permeability for 51Cr as well as by a decreased sensitivity to the detergent Triton-X-100. HSV-2 induced opposite effects on the stability of the membrane in infected cells. In contrast to these findings with HEp-2 cells, opposite results were obtained with primary chick embryo fibroblasts: Infection with HSV-1 rendered the cell membrane more permeable for 51Cr and a reduction of the 51Cr-release was achieved by infection with HSV-2. The results show that HSV-cell interactions depend on the type of the virus as well as on the type of the infected cell.

Animals↗
PubMed1981

[Effect of the acid-base status on circulatory stability during acetate and bicarbonate hemodialysis].

In the preceding circulatory studies (Hampl et al. 1977, Hampl et al. 1978, Hampl et al. 1979, Hampl et al. 1980) we have proved in our patients that during the acetate dialysis (HDA) the circulatory insufficiency results from the inadequate response of the total peripheral vascular resistance (TPR) to the deprivation of the volume. Of these previously studied patients we selected six ones with frequency episodes of symptomatic hypotension during HDA, treated them with bicarbonate dialysis (HDB) and found a good tolerance to the treatment without symptomatic hypotension despite the same deprivation of the volume. We examined invasively the parameters of the circulation during HDB and found in all six patients a stability of the circulation due to the significant increase of the TPR. In addition to this we examined in the intraindividual comparison the arterial acid-base-status with simultaneous measurement of blood pressure and heart frequency in the six patients during five treatments each with HDA and HDB. Arterial PCO2, base excess and standard bicarbonate were significantly higher during HBL compared with HDA. On the other hand under HDB we did not find any significant PO2, O2-saturation and pH values lasting during the period of treatment. We concluded that the adequate adaptation of the vascular TPR to the deprivation of the volume during HDB is to be referred to a sufficient correlation of the metabolic acidosis; in particular to the normalisation of the arterial PCO2.

Acetates↗
PubMed1979

Differences in the morphology of herpes simplex virus infected cells: I. Comparative scanning and transmission electron microscopic studies on HSV-1 infected HEp-2 and chick embryo fibroblast cells.

Infection with herpes simplex virus type 1 (HSV-1) induces different morphological changes in different cell lines. This is demonstrated by comparative scanning (SEM and transmission (TEM) electron microscopic investigations of cell cultures prepared under identical conditions. SEM of HSV-1 infected HEp-2 cells reveals a slightly altered cell surface: only the number of the microvilli is reduced. Large amounts of released virions are detectable adhering to the outer plasma membrane. Ultra-thin sections show typical virus maturation steps in the nuclei (formation of nucleocapsids and virus budding from the inner lamella of the nuclear membrane) and in the cytoplasm (egress of enveloped nucleocapsids through membranous structures). HSV-infected primary chick embryo fibroblast (CEF) cells are characterized by crumpled and rough surfaces without virus particles adhering to the membrane. Ultra-thin sections exhibit atypical virus maturation with many unenveloped nucleocapsids within the cytoplasm. The distribution of HSV-induced antigen(s) on the surface of the infected cells is identical in the two cell systems as determined by the peroxidase labelling technique. The c.p.e. (as seen by phase contrast light microscopy) is similar in both HEp-2 and CEF cells: both fusion and rounding up is induced in the infected cells.

Animals↗