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Biomedical subjects

H Bartels

Publications and source records attributed to H Bartels.

At least 127 records · Page 7Linked to original sources
PubMed1990

Predominant periportal expression of the phosphoenolpyruvate carboxykinase and tyrosine aminotransferase genes in rat liver. Dynamics during the daily feeding rhythm and starvation-refeeding cycle demonstrated by in situ hybridization.

The zonal distribution of phosphoenolpyruvate carboxykinase (PCK) and tyrosine aminotransferase (TAT) mRNA in liver was studied by in situ hybridization with radiolabelled cRNA probes and the abundance of PCK and TAT mRNA was quantified by Northern blot analysis of total RNA with biotinylated cRNA probes. Livers were taken from rats during a normal 12 h day/night rhythm, when they had access to food only during the dark period from 7 pm to 7 am, or during refeeding, when they had access to food after having been starved for 60 h. 1. Daily feeding rhythm: High levels of PCK mRNA were distributed mainly in the periportal and intermediate zone during the fasting period at noon and 6 pm. Feeding caused a rapid decrease in PCK mRNA level and a restriction of PCK mRNA localization to the periportal area within the first 2 h. No further alterations were observed during the following hours of the feeding period. TAT mRNA was distributed also in the periportal and intermediate zone during the fasting period. Feeding first reduced the mRNA level without changing the distribution pattern. Then towards the end of the feeding period TAT mRNA increased again to half-maximal levels and became restricted mainly to the periportal area. 2. Starvation-refeeding cycle: High amounts of PCK mRNA as well as of TAT mRNA were localized predominantly in the periportal and intermediate zone after 60 h of starvation. PCK and TAT mRNA both decreased markedly during the first 2 h of refeeding and then remained almost constant.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1990

Development and evaluation of an enzyme-linked immunoassay for the prostate: specific antigen utilizing two monoclonal antibodies.

PSA is an important tumor-marker for prostatic cancer disease. We developed a sensitive, simple and inexpensive Sandwich ELISA for PSA with two monoclonal antibodies. The precision and reliability of the assay are reflected in the low inter- and intraassay coefficient of variation. PSA was not detectable in sera from normal females (n = 50). Sera from males with different serum levels of PSA (normal males, patients with prostate hypertrophy, prostate cancer patients, n = 79) and 15 prostate cancer patients treated with Zoladex were measured by our ELISA and by a commercially available RIA. The correlation coefficient between these both test systems was close to 1 (r = 0.97).

Antibodies, Monoclonal↗
PubMed1990

Postoperative care and management following three kinds of operation for esophageal cancer.

A total 100 esophageal resections were performed over a recent two year period, employing the following three kinds of operative procedure on 3 groups of patients. Group A, comprised of 37 patients, underwent transhiatal esophagectomy and reconstruction through the posterior mediastinal route. Group B, comprised of 35 patients, underwent resection through a right thoracotomy with reconstruction via the retrosternal route. The 28 patients in group C were further divided into 2 subgroups according to age and underwent a two-stage operation, in which the interval between the first and second operation was 43 hours. The operative mortality rates in each group were 2.7 per cent, 2.9 per cent and 7.1 per cent, in groups A, B and C, respectively. In analyzing the pre- and postoperative cardiopulmonary function, the changeable movement in mean left ventricular stroke work index (LVSWI) was remarkable in group C. In the younger subgroup, and less than 55, the mean LVSWI decreased to 30.3 g.m/m2 12 hours postoperatively, whereas in the older subgroup, and greater than or equal to 55 years, it was significantly (p less than 0.05) higher than that of group A plus group B 48 hours after the first operation; in other words, immediately after the second operation. Consequently, strict control of the flow volume of patients undergoing a two-stage operation is essential in order to optimise the advantages of this method.

Adenocarcinoma↗
PubMed1990

Rapid endothelialization of microporous vascular prostheses covered with meshed vascular tissue: a preliminary report.

The aim of our study was to induce rapid endothelialization of vascular prostheses which replace malfunctioning blood vessels. We developed a technique of meshing a section of autologous arterial or venous tissue, wrapping it around a porous vascular prosthesis and fixing it with a running suture. This combination was used to replace a 1 cm segment of rat abdominal aorta. The implanted specimens were harvested after 8, 16, 24 or 135 d and evaluated for cellular ingrowth and endothelial coverage with light and scanning electron microscopy. All grafts were patent when harvested. Cells of the meshed tissue were observed to migrate through the pores in the prosthetic wall to cover the luminal surface. The presence of meshed vascular tissue around the prosthesis resulted in complete endothelialization within 24 d and sometimes within 8 d after implantation. This endothelial layer is still present after 135 d. In control prostheses without meshed vascular tissue, complete endothelialization takes at least 42 d. We conclude that the application of meshed vascular tissue around porous vascular prostheses results in patent prostheses with a rapidly formed and long-term surviving endothelium layer.

Animals↗
PubMed1990

Vascular thymus transplantation in rats. Technique, morphology, and function.

A new method of thymus transplantation is introduced, in which the graft is directly connected with the recipient's vascular system. This procedure was used both in euthymic rats and congenitally athymic nude rats. At all tested intervals after transplantation thymus grafts hardly differed from the recipient's own thymus in immunohistology and lymphocyte yield. In athymic nude rats, T cell-dependent immunity, tested by mitogen- and alloantigen-induced T cell responses, as well as by antibody production and delayed-type hypersensitivity after ovalbumin administration, showed that vascular thymus grafts could generate T cell functions to euthymic control levels. We conclude that the technique of vascular thymus transplantation represents a valuable tool, either in fundamental research on thymus function, or for the purpose of immune (re)constitution.

Animals↗
PubMed1990

Melphalan and prednisone (MP) versus vincristine, BCNU, adriamycin, melphalan and dexamethasone (VBAM Dex) induction chemotherapy and interferon maintenance treatment in multiple myeloma. Current results of a multicenter trial. The German Myeloma Treatment Group.

277 untreated multiple myeloma patients of stage 1 (n = 33), II (n = 106) and III (n = 138) entered the study. Patients of stage II presenting a progressive tumor (n = 64) initially or during observation (n = 14) were treated with MivP (remissions: 61%). 138 patients of stage III were randomized to receive MivP or VBAMDex treatment. 51% of MivP treated patients responded versus 70% of the VBAMDex group. 71 responders of stage II and III with stable disease were randomized on Ifn-alpha maintenance versus no maintenance treatment. The relapse rate in both groups was 50% after 7 months. 75% survival was greater than 36 months in stage II and 11 months in stage III patients.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1990

[Clonality and stem cell defects in the molecular pathology of chronic myeloproliferative disorders].

The chronic myeloproliferative disorders (CMD) are characterized by sustained or progressive proliferations of bone marrow cells, affecting one or more lineages in varying combinations. They are classified in 4 subgroups but transitional forms and transformations among the different entities are common. Analysing RFLPs and methylation patterns of X-chromosomal genes we could show, that in each entity granulocytes as well as bone marrow cells are of monoclonal origin. These findings support the view that all forms of CMD have in common that they arise from a multipotent hematopoietic stem cell. CML can be differentiated from all other forms of CMD by the Philadelphia-chromosome which on the molecular level has been revealed as bcr-abl gene junction. We investigated 258 cases of CMD for rearrangement of the bcr gene and found that it selectively occurred in CML. The methods applied can be of diagnostic value in differentiating reactive from neoplastic proliferations by analysis of clonality, and in differentiation of CML from other types of CMD by detection of the bcr-rearrangement.

Bone Marrow↗
PubMed1990

[Postoperative lung complications: special problems exemplified by esophageal surgery].

Pulmonary problems in esophageal surgery can result from the resection itself (intraoperative pulmonary trauma), the reconstruction procedure (intrathoracic organ interposition) and aspiration due to postoperative impairment of swallowing. Therapeutic strategies include postoperative ventilation, deflation of the interponate and a special dietary plan. Our rate of 5.2% postoperative pulmonary complications underlines the efficiency of our treatment modalities.

Combined Modality Therapy↗
PubMed1990

[Treatment of postoperative alcohol withdrawal syndrome after esophageal resection].

Prophylaxis and treatment of alcohol withdrawal syndrome following esophagectomy consists of substitution with alcohol (1-2 g/kg/d), monotherapy with Midazolam (0.2-0.4 mg/kg/h) und Clonidin (1-2 mg/d). Out of 218 patients undergoing esophagectomy from X/86 till III/90 52 were classified as alcoholics and divided in 3 comparable groups. The Midazolamgroup showed the best results as far as withdrawal symptoms, time at the ICU, ventilation time, respiratory complications, delirium tremens and mortality are concerned. Patients in the Clonidin-group needed extensive supplimentary sedation.

Alcohol Withdrawal Delirium↗
PubMed1990

[Pellagra in anticonvulsive therapy].

The case of a mentally handicapped female patient is presented who developed typical pellagra with dermatitis, diarrhoea and mental alteration following a long-term antiepileptic treatment with phenytoin, ethosuximide and valproic acid. In addition, she had a deficient meat intake. A course of treatment with multivitamins proved successful in resolving the symptoms within 2 weeks.

Adult↗
PubMed1990

[Sonography in sinus renalis].

The renal sinus (s.r.) of the kidney is an anatomical entity and well correlated with the central echo-band in the nephrosonogram. For the evaluation of this compartment sonography may be the best practicable method. It's important, however, to differentiate between anatomical variations and real pathological findings to avoid diagnostic errors and waste of other procedures. Diverse appearances are demonstrated and discussed.

Humans↗
PubMed1989

[Cimetidine and ethanol].

Cimetidine inhibits hepatic drug metabolism, but its effect on ethanol elimination is less well established. The influence of cimetidine on the kinetics of ethanol is studied with three standardized drinking experiments. Cimetidine had no influence on the absorption or elimination of ethanol. There were significant differences in distribution of ethanol in consequence of inhibition of vascular histamine receptors after cimetidine application.

Adolescent↗
PubMed1989

[Self-mutilation with a coumarin derivative].

The experiment of a self-injury by permanent intoxication with the coumarin derivative Warfarin is described. Various isolated haemostatic defects as differential-diagnostically demarcated causes for the leading symptom decrease of the value of the thromboplastin time which concern the effect of coumarin are mentioned. It is referred to the coagulation-analytic and chemical-toxic methods of proof of coumarins.

Adult↗
PubMed1989

Predominant localization of phosphoenolpyruvate carboxykinase mRNA in the periportal zone of rat liver parenchyma demonstrated by in situ hybridization.

In rat liver parenchyma, expression of the phosphoenolpyruvate carboxykinase (PEPCK) gene was studied by Northern blot analysis with a biotinylated cRNA probe and the zonal localization of PEPCK mRNA was demonstrated by in situ hybridization with a radiolabelled cRNA probe. During the feeding period at night, overall PEPCK mRNA levels were low and PEPCK mRNA was detected only in small areas of the periportal zone. At the beginning of the light period (7 am) the overall PEPCK mRNA level began increasing and the periportal areas containing PEPCK mRNA broadened. The maximum of the total abundance and of the area with high levels of PEPCK mRNA was reached at noon. Fasting for 24-72 h did not cause further significant alterations in the level or localization of PEPCK mRNA. The present data are in line with previous findings of the predominant localization of PEPCK activity and enzyme protein in periportal hepatocytes. They suggest that the heterogeneous expression of the PEPCK gene in rat liver is regulated at the pretranslational level.

Animals↗
PubMed1989

TPA-induced differentiation and adhesion of U937 cells: changes in ultrastructure, cytoskeletal organization and expression of cell surface antigens.

Incubation of the human promonocytic cell line U937 with 12-O-tetradecanoylphorbol-13-acetate (TPA) for 72 h resulted in differentiation into immature macrophage-like cells and was accompanied by marked morphological and functional changes. U937 cells which normally grow in suspension and show a smooth surface, extended pseudopodia and became adherent to each other and to the surface of the culture vessel. Concomitant with the TPA-induced adherence U937 cells ceased to proliferate. Our results show that phorbol ester-treated U937 cells exhibited markedly increased levels of fibronectin and of the cytoskeletal proteins actin, myosin and vimentin including a reorganization of actin and vimentin filaments. The induction of both cellular adherence and growth inhibition were accompanied by a significantly reduced level of cells expressing transferrin receptors and changes in cell surface antigen expression. Here, the expression of the leukocytefunction antigens (LFA-1), including CD11 and CD18 was markedly enhanced during phorbol ester-induced differentiation. TPA-treatment, however, failed to enhance the small amount of U937 cells expressing the monocyte/macrophage-specific CD14 antigen or expressing MHC class-II antigens. A detailed analysis of the CD14 cluster by 7 differential antibodies resulted in an induction of TM1, UCHM1, MEM15, My4, and 3C10, whereas the epitopes recognized by TM2 and Mo2 remained unaltered. Neither indomethacin nor interferon-gamma were capable of inducing a marked expression of these antigen epitopes in TPA-treated cells. Although these data demonstrate that during phorbol ester-induced differentiation U937 cells acquire many properties typically associated with macrophages, the failure to express marked levels of macrophage-specific cell surface antigens suggests a transition of U937 cells from a promonocytic to an immature macrophage intermediate state rather than into mature macrophage-like cells.

Antigens, Surface↗