Detection of chromosomal aberrations in well-differentiated hepatocellular carcinoma by bright-field in situ hybridization.

Differentiation between well-differentiated hepatocellular carcinoma (HCC) and nonmalignant lesions with increased cellular proliferation may be difficult in needle biopsies. Based on recurrent chromosome aberrations known for HCC, we developed a nonfluorescent in situ hybridization technique that allows combination with morphological analysis in bright-field microscopy. Fourteen biopsies of HCC and 31 samples of regenerative nodules (n = 10), chronic hepatitis (n = 10), fibrosis or cirrhosis of unknown origin (n = 5), focal nodular hyperplasia (n = 2), primary biliary cirrhosis (n = 2), steatosis (n = 1), and adenomatous hyperplasia (n = 1) were analyzed with probes specific for the centromeric regions of chromosomes 1, 6, 7, and 8. After microwave pretreatment and in situ hybridization, signals were detected using a tyramine-based system and AEC as substrate. Evaluation of signals was done by conventional bright-field microscopy. Using this approach, aberrant counts were seen for at least one chromosome in 12/14 cases of HCC. In contrast, none of the nonmalignant lesions revealed aberrant counts for any of the chromosomes analyzed. In conclusion, this new combination of in situ hybridization and tyramine amplification allows fast and reliable evaluation of chromosome aberrations in a histomorphological context similar to paraffin immunohistochemistry. Registration of imbalances contributes to a reliable differentiation between malignant and nonmalignant lesions of the liver.     

Erythropoiesis in primary (idiopathic) osteomyelofibrosis: Quantification,PCNA-reactivity,and prognostic impact

In 64 patients with primary (idiopathic) osteomyelofibrosis (OMF), a morphometric analysis has been performed on bone marrow trephine biopsies following sequential doubleimmunostaining with monoclonal antibodies against proliferating cell nuclear antigen (PCNA) and erythroid precursor cells (glycophorin C). The purpose of this study was to quantify erythropoiesis and its PCNA-staining capacity and, further, to determine the impact of these parameters for the development of anemia and for prognosis. In comparison with a control group (15 patients), a significant reduction in the number of erythronormoblasts could be demonstrated, associated with an increase in PCNA-labelling. Moreover, significant correlations between the amount of nucleated erythroid marrow cells and degree of anemia (hemoglobin level, hematocrit, erythrocyte count) and survival could be calculated. Adverse relationships were assessed between number of erythroid cells, thrombocyte count, and spleen size, and also argyrophilic (reticulin/collagen) fiber density. These interactions were thought to reflect the biological behaviour of the disease process, i.e., the progression or extent of myeloid metaplasia. Our findings support ferrokinetic studies suggesting erythroid hypoplasia as one of the major causes of anemia in OMF. The remarkable high PCNA-labelling index of the macrocytic-megaloblastoid appearing erythropoiesis is probably caused by an overexpression of this marker protein. A comparative evaluation of Ki-67 antigen immunostaining in splenic tissue (myeloid metaplasia) and of the PCNA-labelling in pernicious anemia lend support to the assumption of an undue prolongation of the S-phase generated by secondary folate (hematinic) deficiency. © 1994 Wiley-Liss, Inc.     

Interferon-alpha-induced morphological changes of megakaryocytes: a histomorphometrical study on bone marrow biopsies in chronic myeloproliferative disorders with excessive thrombocytosis

Interferon(rIFN)-alpha, a successful therapeutic agent in the control of thrombocytosis, has been shown to suppress human megakaryopoiesis. We investigated bone marrow biopsies from 12 patients with thrombocytosis due to chronic myeloproliferative disorders. Prior to treatment as well as during rIFN-alpha-2c therapy, several morphometric parameters of megakaryopoiesis were evaluated. Megakaryocyte density decreased significantly in all patients, megakaryocyte size decreased in polycythaemia vera, agnogenic myeloid metaplasia, and essential thrombocythaemia, but increased in chronic myeloid leukaemia. The various changes observed during therapy indicate an inhibitory effect of rIFN-alpha-2c on megakaryopoiesis and suggest a selective influence on megakaryocytes at various stages of maturation. Increased numbers of pyknotic (bare) nuclei may reflect a shortening of megakaryocyte life-span. No remarkable changes were found in the fibre content of the bone marrow.     

Phase coherent averaging in magnetic resonance spectroscopy using interleaved navigator scans: compensation of motion artifacts and magnetic field instabilities.

The quality of spectra in (1)H magnetic resonance spectroscopy (MRS) is strongly affected by temporal signal instabilities during the acquisition. One reason for these instabilities are hardware imperfections, e.g., drifts of the main magnetic field in superconducting magnets. This is of special concern in high-field systems where the specification of the field stability is close to the spectral linewidth. A second major potential source of artifacts, particularly in clinical MRS, is patient motion. Using standard acquisition schemes of phase-cycled averaging of the individual acquisitions, long-term effects (field drifts) as well as changes on a shorter time scale (motion) can severely reduce spectral quality. The new technique for volume-selective MRS presented here is based on the additional interleaved acquisition of a navigator signal during the recovery time of the metabolite acquisition. It corrects for temporal signal instabilities by means of a deconvolution of the metabolite and the navigator signal. This leads to phase-corrected individual metabolite scans and upon summation to a phase-coherent averaging scheme. The interleaved navigator acquisition does not require any user interaction or supervision, while sequence efficiency is maintained.     

Cardiac phase contrast gradient echo MRI: measurement of myocardial wall motion in healthy volunteers and patients

A number of methods have been proposed for the noninvasive measurement of myocardial wall motion. The paper describes a strategy for assessing myocardial motion based on the sensitivity of the phase of the MR-signal to motion using a breath-hold phase contrast technique. A motion-sensitized and a motion-compensated MR-signal are measured during successive scans. The difference between the two MR-signals is used to calculate myocardial velocity in all three spatial dimensions. Postprocessing includes the transformation of the measured velocities into an internal coordinate system of the left ventricle. Also various presentation modes and further processing of the received velocity information are provided including calculation of global motion parameters. We examined 20 patients suffering from myocardial infarction. The overall left ventricular motion can be characterized by appropriate parameters describing the rotation and contraction or expansion, respectively. Regional motional disturbances are visualized using parametric images. Contrary to the highly consistent interindividual data in normal volunteers, patients showed significant localized motion deficits.     

The Hemolysis Test of the Gyro C1E3 Pump in Pulsatile Mode

Abstract: While a centrifugal pump is generally used for nonpulsatile blood flow, it can also produce a pulsatile flow by alternating the impeller rotational speed (rpm) periodically. However, there is concern that this centrifugal pump pulsatile mode may induce added hemolysis as a result of the repeated acceleration and deceleration of rpm. Thus, a hemolysis study of the pulsatile modes of the Gyro C1E3 centrifugal pump (Gyro-P) was conducted. The results were then compared with the nonpulsatile mode of the same Gyro pump (Gyro-N) and the nonpulsatile BioMedicus BP-80 (Bio-N) pump. Three different conditions were simulated: left ventricular assist device (LVAD), cardiopulmonary bypass (CPB), and percutaneous cardiopulmonary support (PCPS). The beating rate of the Gyro-P was set at 40 bpm, with repetition of 2 different impeller speeds (the lower rpm being 70% of the higher speed). The 2 impeller speeds were set to obtain the same average flow as that of the nonpulsatile mode. The hemolysis results of the Gyro-P were comparable to or better than those of the Bio-N, and no excessive hemolysis was observed, compared to the Gyro-N. In conclusion, the Gyro-P had an excellent hemolytic characteristic and generated no excessive hemolysis in most clinical usage conditions. With the concern of hemolysis eliminated, this pulsatile mode may have various possible advantages.