Quantitative assessment of right ventricular volumes in severe chronic thromboembolic pulmonary hypertension using transthoracic three-dimensional echocardiography: changes due to pulmonary thromboendarterectomy

AIMS

Evaluation of a three-dimensional reconstruction method to show the changes of right ventricular volume and systolic function when patients undergo pulmonary thromboendarterectomy for chronic thromboembolic pulmonary hypertension.

METHODS AND RESULTS

In the examination of 11 patients (four female, seven male; age 56+/-10 years) before and after pulmonary thromboendarterectomy, end-diastolic and end-systolic right ventricular volumes were determined as a sum total of the calculated volumes of derived parallel slices of the right ventricle. Using a Tomtec workstation and a Vingmed CFM 800 echocardiography device, the acquired data were ECG-and respiration-triggered in the course of transthoracic examination, using step intervals of 5 degrees. The ventricular outline was traced manually on 5mm slices from longitudinal cut planes. For subsequent correction, their area measurements were displayed and the volume cross-checked against the volume from orthogonal cut planes. End-diastolic and end-systolic volumes could be quantified in 11/11 cases before surgery, but data could only be attained for 9/11 patients after surgery, because a limited apical window rendered the postoperative three-dimensional reconstruction impossible in two cases. Before surgery, right ventricular size was larger than normal and systolic function was clearly impaired in all of the patients (end-diastolic volume: 121+/-37 ml; end-systolic volume 91+/-30 ml; ejection fraction 25+/-8%). The decrease in mean pulmonary artery pressure after surgery was significant (47+/-8 vs 26+/-8 mmHg; P<0.05). End-diastolic and end-systolic right ventricular volumes had been reduced (80+/-33 ml and 54+/-31 ml respectively), and the ejection fraction had increased (36+/-9%).

CONCLUSIONS

Successfully performed pulmonary thromboendarterectomy leads to a significant reduction of right ventricular chamber size and improvement of systolic function, which can be determined with great precision and quite easily, using transthoracic three-dimensional echocardiography. Published by Elsevier Science Ltd. All rights reserved.

Simultaneous combination of in situ-EPR/UV-VIS/on line GC: a novel setup for investigating transition metal oxide catalysts under working conditions

In situ-EPR, in situ-UV-VIS spectroscopy and on line-GC have been for the first time simultaneously combined to follow the behaviour of lanthanum-doped CrOx/ZrO2 and CrOx/Al2O3 catalysts during the dehydrogenation of propane to propene.

Enantiomeric resolution of galanthamine and related drugs used in anti-Alzheimer therapy by means of capillary zone electrophoresis employing derivatized cyclodextrin selectors

An analytical assay is presented for the determination of the enantiomeric composition of galanthamine and related synthetic and natural compounds. (-)-Galanthamine is isolated from Galanthus nivalis and is used in this optical pure form in the therapy of Alzheimer's disease. Recent efforts for a total synthesis of unichiral (-)-galanthamine is connected with the need for a fast and reliable assay for the determination of the optical purity of the end product, as well as for optimizing and controlling the final steps in total synthesis particularly the asymmetric transformation of narwedine. In this paper the enantiomeric resolution of these compounds is reported employing a capillary electrophoretic system with beta-cyclodextrin derived chiral selectors. With the proposed system a number of galanthamine and narwedine derived analogous compounds could be separated, including 1-bromo- and N-alkyl-substituted compounds.

Matrix-assisted laser desorption/ionization time-of-flight and nano-electrospray ionization ion trap mass spectrometric characterization of 1-cyano-2-substituted-benz[f]isoindole derivatives of peptides for fluorescence detection

A series of hexa- to decapeptides (molecular mass range 800-1200) were labeled with naphthalene-2,3-dicarboxaldehyde, which preferentially reacts with the primary amino groups of a peptide. A highly stable peptide conjugate is formed, which allows selective analysis by fluorescence at excitation and emission wavelengths of 420 and 490 nm, respectively. After removal of unreacted compounds, the peptide conjugates were characterized by matrix-assisted laser desorption/ionization (MALDI) time-of-flight and nano-electrospray ionization (ESI) ion trap mass spectrometry. They readily form both [M + H]+ ions by MALDI and both [M + H]+ and [M + 2H]2+ ions by ESI. Furthermore, the fragmentation behavior of the N-terminally tagged peptides, exhibiting an uncharged N-terminus, was investigated applying post-source decay fragmentation with a curved field reflector and collision-induced dissociation with a quadrupole ion trap. Fragmentation is dominated in both cases by series of a-, b- and y-type ions and [M + H - HCN]+ ions. Peptide bonds adjacent to the fluorescence label were less susceptible to cleavage than the bonds of the non-derivatized peptide ions. In general, the resulting fragment ion patterns were less complex than those of the underivatized peptides.

Calculation of left ventricular outflow tract area using three-dimensional echocardiography. Influence on quantification of aortic valve stenosis

In 23 patients with aortic valve stenosis (14 male, 9 female, mean age 66 +/- 21.5 years) left ventricular outflow tract cross-sectional area was determined in planimetric fashion using three-dimensional echocardiography. The 3-D data-set for each patient had been acquired in the course of a multiplane transesophageal examination. Aortic valve area was determined using the continuity equation. Results obtained were compared to those calculated by continuity equation using to the conventionally determined LVOT area (a = pi [d/2]2). As reference method the results were compared to invasive measurements. 3-D planimetric determination of LVOT cross-sectional area was possible in 20 of 23 patients. In three patients, this method failed due to artefacts. The mean difference to the conventionally calculated LVOT area amounted to 0.18 cm2 (SD = 0.46). The comparison of AVA determined by continuity equation and by invasive measurement showed a mean difference of -0.074 cm2 (SD = 0.21) for the conventionally calculated LVOT area; for the planimetrically determined LVOT area the mean difference of AVA amounted to -0.03 cm2 (SD = 0.14) (p < 0.05). Planimetric determination of LVOT area using 3-D echocardiography improves the agreement of the continuity equation with invasive measurement.

Species-specific replication of simian virus 40 DNA in vitro requires the p180 subunit of human DNA polymerase alpha-primase

Human cell extracts efficiently support replication of simian virus 40 (SV40) DNA in vitro, while mouse cell extracts do not. Since human DNA polymerase alpha-primase is the major species-specific factor, we set out to determine the subunit(s) of DNA polymerase alpha-primase required for this species specificity. Recombinant human, mouse, and hybrid human-mouse DNA polymerase alpha-primase complexes were expressed with baculovirus vectors and purified. All of the recombinant DNA polymerase alpha-primases showed enzymatic activity and efficiently synthesized the complementary strand on an M13 single-stranded DNA template. The human DNA polymerase alpha-primase (four subunits [HHHH]) and the hybrid DNA polymerase alpha-primase HHMM (two human subunits and two mouse subunits), containing human p180 and p68 and mouse primase, initiated SV40 DNA replication in a purified system. The human and the HHMM complex efficiently replicated SV40 DNA in mouse extracts from which DNA polymerase alpha-primase was deleted, while MMMM and the MMHH complex did not. To determine whether the human p180 or p68 subunit was required for SV40 DNA replication, hybrid complexes containing only one human subunit, p180 or p68, together with three mouse subunits (HMMM and MHMM) or three human subunits and one mouse subunit (MHHH and HMHH) were tested for SV40 DNA replication activity. The hybrid complexes HMMM and HMHH synthesized oligoribonucleotides in the SV40 initiation assay with purified proteins and replicated SV40 DNA in depleted mouse extracts. In contrast, the hybrid complexes containing mouse p180 were inactive in both assays. We conclude that the human p180 subunit determines host-specific replication of SV40 DNA in vitro.

The mouse DNA polymerase alpha-primase subunit p48 mediates species-specific replication of polyomavirus DNA in vitro

Mouse cell extracts support vigorous replication of polyomavirus (Py) DNA in vitro, while human cell extracts do not. However, the addition of purified mouse DNA polymerase alpha-primase to human cell extracts renders them permissive for Py DNA replication, suggesting that mouse polymerase alpha-primase determines the species specificity of Py DNA replication. We set out to identify the subunit of mouse polymerase alpha-primase that mediates this species specificity. To this end, we cloned and expressed cDNAs encoding all four subunits of mouse and human polymerase alpha-primase. Purified recombinant mouse polymerase alpha-primase and a hybrid DNA polymerase alpha-primase complex composed of human subunits p180 and p68 and mouse subunits p58 and p48 supported Py DNA replication in human cell extracts depleted of polymerase alpha-primase, suggesting that the primase heterodimer or one of its subunits controls host specificity. To determine whether both mouse primase subunits were required, recombinant hybrid polymerase alpha-primases containing only one mouse primase subunit, p48 or p58, together with three human subunits, were assayed for Py replication activity. Only the hybrid containing mouse p48 efficiently replicated Py DNA in depleted human cell extracts. Moreover, in a purified initiation assay containing Py T antigen, replication protein A (RP-A) and topoisomerase I, only the hybrid polymerase alpha-primase containing the mouse p48 subunit initiated primer synthesis on Py origin DNA. Together, these results indicate that the p48 subunit is primarily responsible for the species specificity of Py DNA replication in vitro. Specific physical association of Py T antigen with purified recombinant DNA polymerase alpha-primase, mouse DNA primase heterodimer, and mouse p48 suggested that direct interactions between Py T antigen and primase could play a role in species-specific initiation of Py replication.

Detection of chromosome aberrations in the human interphase nucleus by visualization of specific target DNAs with radioactive and non-radioactive in situ hybridization techniques: diagnosis of trisomy 18 with probe L1.84

The localization of chromosome 18 in human interphase nuclei is demonstrated by use of radioactive and non-radioactive in situ hybridization techniques with a DNA clone designated L1.84. This clone represents a distinct subpopulation of the repetitive human alphoid DNA family, located in the centric region of chromosome 18. Under stringent hybridization conditions hybridization of L1.84 is restricted to chromosome 18 and reflects the number of these chromosomes present in the nuclei, namely, two in normal diploid human cells and three in nuclei from cells with trisomy 18. Under conditions of low stringency, cross-hybridization with other subpopulations of the alphoid DNA family occurs in the centromeric regions of the whole chromosome complement, and numerous hybridization sites are detected over interphase nuclei. Detection of chromosome-specific target DNAs by non-radioactive in situ hybridization with appropriate DNA probes cloned from individual chromosomal subregions presents a rapid means of identifying directly numerical or even structural chromosome aberrations in the interphase nucleus. Present limitations and future applications of interphase cytogenetics are discussed.

Clinical evaluation of a specific benzodiazepine antagonist (RO 15-1788). Studies in elderly patients after regional anaesthesia under benzodiazepine sedation

The efficacy, usefulness and side effects of RO 15-1788 (RO), a specific benzodiazepine (BZD) antagonist, have been evaluated. Sixty-two patients (ASA I-III, mean age 72 +/- 9 yr) scheduled for urological surgery under regional anaesthesia and BZD sedation received placebo or RO in a randomized, double-blind fashion at the end of the procedure, following sedation with midazolam. When compared with placebo, RO improved alertness and collaboration for 15 min, and suppressed anterograde amnesia for 60 min. No major side effect was noted, although five patients became anxious after administration of RO. Two cases of a paradoxical reaction to midazolam were treated successfully by RO.

[T2-analysis of normal and pathological structures of the head]

Analyses of T2 values (spin-spin relaxation time constant) in magnetic resonance tomography were carried out in 29 patients with brain tumours. 21 of these had tumours of the glioma group (17 astrocytomas WHO I-III and oligoastrocytomas, 4 glioblastomas). Measurements were effected both pixel by pixel and according to relevant ROI (regions of interest). Although the measurements yielded a T2 value which was typical of the disease, it was individually difficult to effect proper grading on account of the scatter occurring from case to case. Markedly more relevant information was obtained by the introduction of profile measurements in T2 images. The relation between T2 profile and histology of the gliomas permits rough grading between more or less differentiated gliomas.