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Biomedical subjects

M Wagner

Publications and source records attributed to M Wagner.

At least 649 records · Page 36Linked to original sources

[Proliferation kinetic studies in the syngeneic liver transplantation mode in the rat. Effect of re-arterialization on the transplant].

Successful orthotopic liver transplantation (OLT) can be achieved in the rat. We used bromo-2-deoxyuridine (BrdU) as a proliferation marker to document morphological differences between OLT with and without rearterialization. Animals with portal anastomosis alone had a significantly increased proliferation rate of hepatocytes, Kupffer cells, and bile duct epithelial cells, as indicated by strong staining with BrdU, 8 days post-transplant compared to animals with rearterialization. Regeneration of ischemically damaged liver parenchymal cells may account for this observation. Thus, OLT with rearterialization appears to be the more physiological transplant model.

Anastomosis, Surgical↗

Clinical and polymyographic investigation of spasmodic torticollis.

Polymyographic recordings were used to identify the most dystonic muscles suitable for local injection with botulinum toxin in 100 patients with spasmodic torticollis (TS). Rotating TS (72% of the patients) was due to dystonic activity of the splenius muscle ipsilateral to and/or the sternocleidomastoid muscle contralateral to the side of chin deviation. One-third of these patients had also dystonic activation of the contralateral splenius muscle and, rarely, the contralateral trapezius muscle. Ten patients had laterocollis due to dystonic activation of all recorded muscles on one side of the neck. Nine patients had retrocollis due to activity of both splenius muscles and rarely additional activity in both trapezius muscles. The type of dystonic muscle activity was found to be tonic, phasic or tremulous. Besides the evaluation of spontaneous dystonic EMG activity further examination during the "geste antagoniste" or the muscle activity during rotating head movements can provide additional information. It is concluded that polymyography may provide a rationale for identifying the dystonic muscles underlying the different forms of TS. It may prove to be helpful for the successful therapy with botulinum toxin and may be useful in differentiating tremulous torticollis from other types of head tremor.

Adolescent↗

Treatment of spasmodic torticollis with local injections of botulinum toxin. One-year follow-up in 37 patients.

Thirty-seven patients with spasmodic torticollis (cervical dystonia) who received repeated local injections of botulinum toxin have been followed up for a mean period of 12.3 (10-29) months, during which time 138 treatment sessions were performed. Mean doses per muscle averaged 320 mouse units (mu; range 160-1000 mu botulinum toxin A prepared by CAMR, Porton Down, UK). Eighty-six per cent of patients experienced significant improvement of posture and 84% of those with pain had relief following the first injection. Muscular patterns of recurrent torticollis were relatively constant and in most patients efficacy was maintained with subsequent injections, while 15% of all follow-up sessions failed. Only 2 of 37 patients were consistent nonresponders; 22% and 10% of all sessions were complicated by transient dysphagia and weakness of neck muscles, respectively. It is concluded that local botulinum toxin injections can be a safe and efficaceous long-term treatment of spasmodic torticollis and that optimal doses should be between 200 and 400 mu/muscle.

Botulinum Toxins↗

[Judgement of prognosis in multiple trauma of patients with blunt abdominal injuries based on different useful trauma scores].

The use of trauma indices for characterisation of polytraumatized patients concerning prognoses is being discussed for nearly 30 years. In the seventies a couple of trauma indices were developed. Some of them are in use all over the world. In the Department for Trauma surgery in the General Hospital of Salzburg three of the common trauma scores were analysed and compared with one another: Injury Severity Score (Baker), Polytraumascore of the University Clinic of Hannover, Trauma index (Schreinlechner and Eber). As a rule most studies presently published are based on the Injury Severity Score. In a retrospective analysis of 62 polytraumatized patients we could show that the Trauma index of Schreinlechner and Eber is more practicable for classification of polytrauma because it shows a good correlation of score, fatality and prognoses.

Abdominal Injuries↗

Localization of the cholesterol oxidase in Rhodococcus erythropolis IMET 7185 studied by immunoelectron microscopy.

Rhodococcus erythropolis IMET 7185 produces an inducible cholesterol oxidase (COD) which can easily be extracted by treatment of cells with 0.1% Triton X-100. The yield of the enzyme was 3.3 U/g wet wt from induced cells, which is about 5 times more than from non-induced cells. A study of the location of COD on intact cells and on ultrathin sections by means of immunogold electron microscopy revealed the following distribution, which corresponds with the biochemical results: (1) COD, which is extractable by the detergent, was localized in a distance up to 80 nm above the cell surface. It belongs to a surface layer, which only became visible after lysine/glutaraldehyde treatment and staining with ruthenium red, indicating a high carbohydrate content. (2) Non-extractable COD was found on the cell surface in a shorter distance to the cell wall as well as within the cell wall, in the cytoplasmic membrane and in the peripheral cytoplasm. In the latter clusters of gold particles on some places suggest the presence of larger amounts of insoluble enzyme.

Blotting, Western↗

Signal transduction in murine B16 melanoma cells.

The relationship between lung colonization and signal transduction was investigated for six B16 melanoma variants. A range of experimental metastatic potential (as determined by lung colonization), forskolin-stimulated cyclic AMP accumulation and FCS-stimulated protein kinase C activity was found. The major findings were that: (1) cells with the highest agonist-stimulated cyclic AMP production were those with the highest level of membrane-associated protein kinase C activity; (2) clones which differed in protein kinase C levels and distribution did so in the presence but not in the absence of foetal calf serum; and (3) no simple relationship was seen between either signal transduction system and lung colonization for all six variants. Altered ras expression was also excluded as an explanation for the differences in signal transduction and lung colonization potential which were observed. We conclude that differences in signal transduction in vitro between these cells do not relate simply to lung colonization potential in vivo.

Animals↗

Intracellular regulation of cell adhesion to extracellular matrix components in murine B16 melanoma cells.

The involvement of signal transduction systems in the initial attachment of two murine B16 melanoma clones of differing metastatic potential to extracellular matrix components was examined to learn more of the early events in cell-matrix interaction. Clones of high and low metastatic capacity attached similarly in the absence of any stimulators, exhibiting a two phase time course of attachment with 100% attachment by 60 min. A slight difference in attachment characteristics between the clones was seen in response to phorbol ester stimulation, which significantly inhibited attachment of the low metastatic clone but which had no effect on the highly metastatic clone. Total protein kinase C activity and distribution was similar for both clones. Attachment of both clones was severely reduced, however, if intracellular calcium was elevated or intracellular calmodulin inhibited. This study suggests that signal transduction mechanisms are involved in melanoma cell attachment to matrix proteins and offers an approach to pharmacological manipulation of these cell-matrix interactions which may be relevant to reducing metastatic spread.

Animals↗

Flow cytometric analysis of lymphocyte phenotypes in bronchoalveolar lavage fluid: comparison of a two-color technique with a standard immunoperoxidase assay.

Characterization of lymphocytes in bronchoalveolar fluid has provided insight into the pathogenesis of many pulmonary diseases. Identification of lymphocyte phenotypes has become highly successful due to development of specific monoclonal antibodies and reliable methods for detecting labeled cells such as flow cytometry (FCM) and immunocytochemistry. FCM permits rapid screening of many cells, but this analysis may be confounded by heterogeneity in the size and granularity of the cells being evaluated. Such heterogeneity may lead to exclusion of cells of interest and inclusion of unwanted cells. Often peripheral blood leukocytes are used to define the gate for lung lymphocytes, but this gate may be inappropriate due to considerable variation in size and granularity of cells in bronchoalveolar lavage (BAL) fluid. Here we report an alternative method for generating a gate which employed fluorescence and side scatter signals to analyze lymphocyte subsets in BAL fluid by FCM. This gating technique avoids the pitfalls inherent in using the conventional lymphocyte gate to analyze lung cells. To validate this approach, we compared the results generated by this gate and those from the conventional forward/side light scatter gate to results derived from an immunocytochemical technique (ABC) that has been extensively employed in our laboratory to identify lymphocyte subsets in blood and lavage fluid. FCM tended to underestimate the proportions of T-cell subsets compared with ABC when the conventional gate was used. Counting only cells that stained with fluorescein-conjugated anti-CD45 antibody and that had side scatter properties of lymphocytes, however, resulted in excellent agreement between FCM and ABC. It appears that the CD45+/side scatter gate includes the vast majority of lymphocytes in BAL fluid while excluding most of the nonlymphoid cells that contaminate the conventional gate. It was this latter group of cells, and erythrocytes in particular, that led to the artificially low values for lymphocyte phenotypes in BAL fluid by FCM when the conventional lymphocyte gate was used. Although erythrocytes in BAL fluid may be eliminated by hypotonic lysis, this may also result in contamination of the conventional lymphocyte gate with nuclear debris and particulates from macrophages. Despite these advantages, the fluorescence/side scatter gate may not always be optimal for the evaluation of T lymphocytes if BAL fluid contains CD45+, nonlymphoid cells with low side light scatter. In these instances, additional antibodies such as anti-CD14 and anti-CD11 may be employed to determine the size of contaminant monocytic cells and neutrophils.(ABSTRACT TRUNCATED AT 400 WORDS)

Bronchoalveolar Lavage Fluid↗

MELAS syndrome with mitochondrial tRNA(Leu)(UUR) mutation: correlation of clinical state, nerve conduction, and muscle 31P magnetic resonance spectroscopy during treatment with nicotinamide and riboflavin.

We report a patient with mitochondrial encephalomyopathy, lactic acidosis, and strokelike episodes treated with riboflavin and nicotinamide for 18 months, during which time previously frequent encephalopathic spells ceased. To confirm clinical benefit, we withdrew treatment and monitored response with muscle 31P magnetic resonance spectroscopy (MRS) and sural nerve conduction studies. Of three prospectively chosen MRS variables, two changed coincidentally with clinical end points; phosphocreatine (PCr)/adenosine triphosphate recovery rates fell in parallel with sural nerve sensory amplitudes, and a drop in muscle bioenergetic efficiency (relationship of inorganic phosphate/PCr to the accelerating force of contracting muscle) coincided with development of encephalopathy. Investigations revealed a deficiency of respiratory complex I and mutation of the mitochondrial tRNA(Leu)(UUR). We suggest that a defective cellular energy state in mitochondrial disease may be partially treatable and that changes seen in appropriate muscle spectroscopy studies may parallel improvement in brain and peripheral nerve function.

Adult↗

Regional differences in retinoid release from embryonic neural tissue detected by an in vitro reporter assay.

Retinoic acid and related retinoids have been suggested to contribute to the pattern of cell differentiation during vertebrate embryonic development. To identify cell groups that release morphogenetically active retinoids, we have developed a reporter assay that makes use of a retinoic acid inducible response element (RARE) to drive lacZ or luciferase reporter genes in stably transfected cell lines. This reporter gene assay allows detection of retinoids released from embryonic tissues over a range equivalent to that induced by femtomole amounts of retinoic acid. We have used this assay first to determine whether the floor plate, a cell group that has polarizing properties in neural tube and limb bud differentiation, is a local source of retinoids within the spinal cord. We have also examined whether the effects of exogenously administered retinoic acid on anteroposterior patterning of cells in the developing central nervous system correlate with differences in retinoid release from anterior and posterior neural tissue. We find that the release of morphogenetically active retinoids from the floor plate is only about 1.5-fold that of the dorsal spinal cord, which does not have neural tube or limb polarizing activity. These results suggest that the spatial distribution of retinoid release from spinal cord tissues differs from that of the neural and limb polarizing activity. This assay has also shown that retinoids are released from the embryonic spinal cord at much greater levels than from the forebrain. This result, together with previous observations that the development of forebrain structures is suppressed by low concentrations of retinoic acid, suggest that the normal development of forebrain structures is dependent on the maintenance of low concentrations of retinoids in anterior regions of the embryonic axis. This assay has also provided initial evidence that other embryonic tissues with polarizing properties in vivo release retinoids in vitro.

Animals↗

Commentary: the public health consequences of restricted induced abortion--lessons from Romania.

The question of whether abortion should be legal is currently being decided in many countries. Although much of the discussion has focused on ethical issues, the public health consequences should not be overlooked and should be addressed realistically and responsibly. Nowhere are the public health manifestations of restricted abortion more apparent than in Romania. The pronatalist policies of the Ceaucescu regime resulted in the highest maternal mortality rate in Europe (approximately 150 maternal deaths per 100,000 live births) and in thousands of unwanted children in institutions.

Abortion, Illegal↗

Closely linked H2B genes in the marine copepod, Tigriopus californicus indicate a recent gene duplication or gene conversion event.

Two nonallelic histone gene clusters were characterized in the marine copepod, Tigriopus californicus. The DNA sequence of one of the clusters reveals six genes in the contiguous arrangement of H2B, H1, H3, H4, H2B and H2A. The order of genes within the second cluster is H3, H4, H2B and H2A. There is no evidence for the presence of an H1 gene in this cluster. Comparison of the three copepod H2B genes reveals a high degree of similarity between the 5' upstream regions and between the amino terminal halves of the two H2B genes found within the same cluster. From these data we infer that gene duplication and/or gene conversion events occurred within this cluster in the recent past.

Alleles↗

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Famous Persons↗

[Thoracoscopic use of staplers. New possibilities for minimally invasive diagnosis and therapy].

Thoracoscopic resection of peripheral lung tissue is possible by using special staplers (Endo-GIA). Main indications for using this technique are the treatment of a spontaneous pneumothorax by resection of bullous lung areas (15 patients) and the excision of macro biopsies for diagnostic reasons (13 patients). It is reported about the technique and the early outcome of these 28 thoracoscopically performed lung resections. This way minimally invasive procedure is combined with well-established surgical technique.

Biopsy↗

Specific neurotoxic effects of different organic solvents on dissociated cultures of the nervous system.

Pure neurons were prepared from dorsal root ganglia (DRG) of 8 day old chick embryos (E8). The substances tested in this model were pure n-hexane, 2.5-hexanedione (2.5 HD) and methyl-ethyl-ketone (MEK). Differentiated cultures were exposed to these neurotoxins after two days in culture and then examined over a period of up to one week. For all three substances a specific neurotoxic effect could be demonstrated: (i) n-Hexane mainly altered the neurites, leading to focal swellings and in a second step to degenerative changes in glial cells; (ii) 2.5 HD had a minor effect on neurons and proved to be mainly gliatoxic; (iii) MEK primarily affected the neurons by swelling and disintegration of the cell body.

Animals↗

Cost containment: carrot or the stick?

All sides in the debate over healthcare reform seem to agree that it's an idea whose time has come. The consensus appears to be that the first generation of cost curbs failed to do the job. But when will the nation see real cost containment? And what form will it take? Proposals run the gamut from free-market approaches to greater governmental intervention.

Cost Control↗