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Biomedical subjects

M Heberer

Publications and source records attributed to M Heberer.

At least 127 records · Page 7Linked to original sources
PubMed1984

[Prospective study of complications of central venous catheters].

The complications of central venous catheters used for immediate postoperative nutrition and monitoring were evaluated in 120 patients. Two patients had to be excluded due to an irregular protocol. 149 central venous catheters were placed in the remaining 118 patients. As to the access, the subclavian vein was used in 72.3%, the v. jugularis interna in 18.9%. The catheters were in average 11.7 days in place giving a total of 1392 catheter days. The end of therapy was the most frequent reason for removal of the catheter (81.6%) followed by septic (4.1%) and mechanical problems (8.8%). Venous thrombosis was observed in 2 patients, and embolisation of a catheter fragment and acute infusothorax each in 1 patient. 13% of the catheters were found to be malpositioned, and malposition was identified as a risk factor for thrombosis.--It is concluded from the comparison of these results with the literature, that the central venous catheter for parenteral nutrition has a risk of complication greater than 5% and therefore requires a clear indication. X-ray-control of catheter position is obligatory and malpositioned catheters are to be corrected. If the parenteral regimen is low in glucose concentration and osmolarity, blood sampling and monitoring via the same central venous line does not appear to increase the rate of complications.

Adult↗
PubMed1984

Prevention of radiation injuries to the small intestine.

The removable synthetic "pelvic spacer" prevents intestinal loops from sliding down into the area most heavily exposed to irradiation during a full course of radiotherapy for abdominopelvic neoplasia. Furthermore, it provides a homogeneous distribution of roentgenograms and allows higher dosages of radiation. It reduces possible sequelae and offers new possibilities for radiotherapy of tumors of the pelvis. The removal of the spacer is disadvantageous but clearly compensated by a more curative treatment.

Abdominal Neoplasms↗
PubMed1983

Chemiluminescence of granulocytes and monocytes in diluted whole blood samples: a tumor marker?

Granulocytes and monocytes can attack malignant cells by activated oxygen species. They thereby emit photons which may be measured as chemiluminescence (CL). The zymosan-induced and luminol-amplified CL response of granulocytes and monocytes was measured in diluted whole blood samples of healthy volunteers and patients with benign and malignant disease. In tumor patients the CL activity was significantly stimulated. Following tumor reduction by radical or palliative operations, the CL values decreased to normal within weeks, whereas no response was seen after exploratory laparotomy without tumor reduction. Operations for benign disease did not influence the CL activity. The results suggest that the stimulation of CL activity in tumor patients is reversible. CL measurements in whole blood samples may play a future role as a nonspecific tumor marker.

Granulocytes↗
PubMed1983

Chemiluminescence measurements of immune cells--a tool in immunobiology and clinical research.

Since the initial observation of chemiluminescence associated with metabolic stimulation of polymorphonuclear leukocytes a multitude of studies have confirmed that chemiluminescence is a) dependent on the generation of activated oxygen species and b) intimately correlated to the paramount function of granulocytes: to kill bacteria and to cause tissue damage at sites of chronic inflammation. Chemiluminescence is not exclusively generated by polymorphonuclear leukocytes and certainly not only generated by phagocytic stimuli. Besides phagocytic stimuli, surface active reagents (e.g. phorbol myristate acetate), lectins, antigen-antibody complexes, complement components, and some lymphokines are able to evoke chemiluminescence responses in polymorphonuclear leukocytes, monocytes, and macrophages. In this contribution we present evidence for a dependence of macrophage chemiluminescence during phagocytosis on the calcium binding protein calmodulin. In a second example of macrophage chemiluminescence we demonstrate that macrophage chemiluminescence is a good tool for testing the mediator function of a lymphokine, namely macrophage cytotoxicity factor. In a clinical application we determined the zymosan-induced and luminol-amplified chemiluminescence in diluted whole blood samples from healthy volunteers to establish the normal range of chemiluminescence activity of phagocytic cells. A significant day time variability of the chemiluminescence activity was observed in 6 volunteers. Therefore, blood sampling for the chemiluminescence measurements was standardized. Compared with the control group the specific chemiluminescence activity (activity related to 10(3) phagocytic cells) was significantly increased in both 1) patients with acute inflammatory disease and 2) in patients with carcinoma. The specific chemiluminescence activity of the two groups of patients did not differ.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1982

Measurement of chemiluminescence in freshly drawn human blood. II. Clinical application of zymosan-induced chemiluminescence.

The aim of the present study was to investigate chemiluminescence (CL) of stimulated peripheral phagocytic cells (PC, i.e. granulocytes and monocytes) in patients with malignant disease at various stages. As a first step the zymosan-induced and luminol-amplified CL was determined in diluted whole blood samples from healthy volunteers. A characteristic daytime dependence of the CL activity was observed in six volunteers which had to be taken into account for blood sampling. The detectable CL was demonstrated to depend on the number of erythrocytes in the assay, but correction for this is not necessary for clinical investigation. The specific CL activity (activity related to 10(3) PC, was significantly but identically increased both in 1) patients with acute inflammatory disease and 2) in patients with carcinoma. The total CL activity (activity/microliter whole blood), however, was significantly increased in patients with acute inflammation as compared to the tumour group. This greatly reflects the leucocytosis of patients with acute inflammation. In a small number of patients with benign and malignant disease the CL of PC was measured both pre- and postoperatively. Operations in benign disease and palliative operations in malignancy did not influence the CL activity. In contrast, CL activity returned to normal after clinical cure by radical tumour resection.

Blood↗
PubMed1979

[Long-term observations on different methods of nephropexy].

In 29 patients with nephroptosis two different methods of nephropexy were compared; nephropexy using sutures passing through the parenchyma (n = 16) and nephropexy using tissue adhesives (n = 13). The first group was mobilized 3.5 days after operation, whereas the second group was mobilized one day after operation. On later follow-up 79% of the patients had no or minor complaints. Those patients who had the same disturbances as preoperatively had all been treated by nephropexy using sutures passing through the parenchyma. In 56% of this group radiological recurrence was seen, whereas in the group using tissue adhesives there was only 8% radiological recurrence. We think therefore that the nephroxepy using tissue adhesive is the simplest and least traumatic method.

Adult↗
PubMedDate not supplied

Enhanced cartilage tissue engineering by sequential exposure of chondrocytes to FGF-2 during 2D expansion and BMP-2 during 3D cultivation.

Bovine calf articular chondrocytes, either primary or expanded in monolayers (2D) with or without 5 ng/ml fibroblast growth factor-2 (FGF-2), were cultured on three-dimensional (3D) biodegradable polyglycolic acid (PGA) scaffolds with or without 10 ng/ml bone morphogenetic protein-2 (BMP-2). Chondrocytes expanded without FGF-2 exhibited high intensity immunostaining for smooth muscle alpha-actin (SMA) and collagen type I and induced shrinkage of the PGA scaffold, thus resembling contractile fibroblasts. Chondrocytes expanded in the presence of FGF-2 and cultured 6 weeks on PGA scaffolds yielded engineered cartilage with 3.7-fold higher cell number, 4.2-fold higher wet weight, and 2.8-fold higher wet weight glycosaminoglycan (GAG) fraction than chondrocytes expanded without FGF-2. Chondrocytes expanded with FGF-2 and cultured on PGA scaffolds in the presence of BMP-2 for 6 weeks yielded engineered cartilage with similar cellularity and size, 1.5-fold higher wet weight GAG fraction, and more homogenous GAG distribution than the corresponding engineered cartilage cultured without BMP-2. The presence of BMP-2 during 3D culture had no apparent effect on primary chondrocytes or those expanded without FGF-2. In summary, the presence of FGF-2 during 2D expansion reduced chondrocyte expression of fibroblastic molecules and induced responsiveness to BMP-2 during 3D cultivation on PGA scaffolds.

Actins↗
PubMedDate not supplied

Role of glutamine in the immune response in critical illness.

The dependence of human lymphocyte functions on the exogenous provision of glutamine (GLN) was evaluated in a series of in vitro experiments. The transcription of early activation markers (IL-2, IL-2-receptor, IL-4, IL-4, GM-CSF, IFN gamma) as evaluated by polymerase chain reaction was observed even in the absence of exogenous GLN. In contrast, later events of lymphocyte activation including cytokine production, proliferation of lymphocytes and lymphokine-activated killer cell activity were found to depend on exogenous GLN provision. These in vitro results are discussed in the context of established data on the reduction of peripheral blood GLN concentrations in critically ill patients and in view of recent studies reporting improved outcome of critically ill patients following GLN substitution. By and large, these data support the concept of GLN substitution in critical illness. However, the definition of indications and dose-response relationships clearly require further clinical studies.

Cells, Cultured↗
PubMedDate not supplied

Intralipid-based short-term total parenteral nutrition does not impair small intestinal mucosa-related cellular immune reactivity in the healthy rat.

BACKGROUND: The lipid component of total parenteral nutrition (TPN) has reportedly been associated with trophic effects on the intestinal mucosa and suppressive effects on the immune system. METHODS: We have challenged these hypotheses using a 7-day TPN rodent model comparing the effects of isocaloric, isonitrogenous lipid-based (TPN-lipid, 50% of calories as long-chain triacylglycerol) and carbohydrate-based TPN (TPN-CH, 100% of calories as carbohydrates) on mucosal morphology and immune function. Enterally fed animals were included to establish a baseline for immunologic read-outs. The study was performed in healthy, metabolically stable animals to avoid interference by septic or trauma-related stress factors. RESULTS: Both TPN regimens resulted in a significantly smaller weight gain (TPN-lipid, 29.8 +/- 4.0 g; TPN-CH, 30.3 +/- 4.4 g) compared with enterally fed reference animals (49.2 +/- 3.2 g; p = .007), with no difference in nitrogen balance between the TPN groups. Mucosal sucrase activity was significantly lower in both TPN groups (TPN-lipid, 8.8 +/- 1.0 x 10(-7) katal per gram (kat/g) of protein; CH: 11.9 +/- 1.6 x 10(-7) kat/g of protein) compared with enteral feeding (17.4 +/- 0.9 x 10(-7) kat/g of protein; ANOVA: p = .0007). Morphometric analysis of the small intestine revealed no differences between the two TPN groups although a significantly depressed villus height in the TPN-lipid group could be observed in comparison to enterally fed reference rats (TPN-lipid, 0.47 +/- 0.02; TPN-CH, 0.50 +/- 0.01; enteral, 0.56 +/- 0.02 mm; ANOVA: p = .0298). Light and electron microscopy revealed a normal surface architecture in all three groups of rats. Cellular immune reactivity was evaluated using a novel specific immunization protocol: animals were immunized against OVA 4 weeks before TPN. OVA-induced lymphoproliferative responses and phenotypic data from draining popliteal and mesenteric lymph nodes were evaluated after the different regimens. Results did not differ among the three groups. CONCLUSIONS: In healthy rodents, short-term lipid-based and carbohydrate-based TPN regimens lead to limited mucosal atrophy with preserved surface architecture compared with enteral feeding. However, peripheral and mesenteric cellular immune responsiveness after both TPN regimens remained comparable to enterally fed reference animals. Therefore, mesenteric and systemic cellular immune reactivity does not appear to be impaired by lipid-based or carbohydrate-based TPN.

Animals↗
PubMedDate not supplied

Bi-zonal cartilaginous tissues engineered in a rotary cell culture system.

In this study, we aimed at validating a rotary cell culture system (RCCS) bioreactor with medium recirculation and external oxygenation, for cartilage tissue engineering. Primary bovine and human culture-expanded chondrocytes were seeded into non-woven meshes of esterified hyaluronan (HYAFF-11), and the resulting constructs were cultured statically or in the RCCS, in the presence of insulin and TGFbeta3, for up to 4 weeks. Culture in the RCCS did not induce significant differences in the contents of glycosaminoglycans (GAG) and collagen deposited, but markedly affected their distribution. In contrast to statically grown tissues, engineered cartilage cultured in the RCCS had a bi-zonal structure, consisting of an outgrowing fibrous capsule deficient in GAG and rich in collagen, and an inner region more positively stained for GAG. Structurally, trends were similar using primary bovine or expanded human chondrocytes, although the human cells deposited inferior amounts of matrix. The use of the presented RCCS, in conjunction with the described medium composition, has the potential to generate bi-zonal tissues with features qualitatively resembling the native meniscus.

Adult↗