Quantitatively assessed coronary collateral circulation and restenosis following percutaneous revascularization

AIMS

A high degree of collateral supply to a vascular area where a percutaneous transluminal coronary angioplasty (PTCA) has been performed represents a haemodynamic force competing with the antegrade flow through the dilated lesion. Therefore, our purpose was to determine whether patients with restenosis following PTCA have a higher collateral flow to the recipient vessel than patients without restenosis.

METHODS AND RESULTS

In 200 consecutive PTCA patients, an intracoronary pressure-derived collateral flow index (CFI) was determined quantitatively during balloon occlusion, using simultaneous measurements of the mean aortic pressure (P(ao)) and of the intracoronary pressure distal to the occluded stenosis (P(occl)), as well as the estimated central venous pressure (CVP=5 mmHg): CFI=(P(occl)-CVP)/(P(ao)-CVP). Sixty-four patients had an angiographic follow-up examination after at least 2 months, and were subdivided into patients with restenosis (>50% diameter stenosis, n=34) and patients without restenosis (n=30). Patients with restenosis had a significantly higher collateral flow index at the initial coronary angiography than patients without restenosis (0.26 +/- 0.14 vs 0.12 +/- 0.09; P<0.0001).

CONCLUSIONS

Patients with restenosis after PTCA show a more extended collateral supply to this recipient area than patients without restenosis. Well developed collaterals to a revascularized region are a risk factor for restenosis of the treated lesion.

Quantification of long-chain aldehydes by gas chromatography coupled to mass spectrometry as a tool for simultaneous measurement of plasmalogens and their aldehydic breakdown products

The cleavage of the specific vinyl ether linkage at the sn-1 position of plasmalogens leads to the formation of two products: the 1-lyso-2-acyl glycerophospholipid and a long-chain fatty aldehyde. Plasmalogens are measured by quantifying one of these two products. In this paper, we describe a rapid and sensitive procedure for measuring plasmalogens via quantification of long-chain fatty aldehydes. After lipid extraction, the sn-1 vinyl ether bond of plasmalogens is cleaved by acidic hydrolysis. The produced aldehydes are then derivatized with (pentafluorobenzyl)hydroxylamine hydrochloride and analyzed by gas chromatography/mass spectrometry in selected-ion mode. Plasmalogens are then indirectly quantified by subtracting the free aldehydes obtained without prior HCl treatment from the total aldehydes obtained after acidic hydrolysis. This method is applied to three rat brain areas selected for this study. Two of these are affected in neurodegenerative diseases (cerebral cortex and hippocampus) and one is rich in white matter (cerebellum). In comparison to other procedures, the advantages of this method are not only its usefulness in plasmalogen quantification but also the identification of aldehydic breakdown products.

Percutaneous closure of patent foramen ovale in patients with paradoxical embolism: long-term risk of recurrent thromboembolic events

BACKGROUND

Patients with a patent foramen ovale (PFO) and paradoxical embolism are at risk for recurrent thromboembolic events. This study investigated the long-term risk of recurrent thromboembolic events in patients with PFO and paradoxical embolism after percutaneous PFO closure.

METHODS AND RESULTS

Since 1994, a total of 80 patients with PFO and at least 1 paradoxical embolic event (transient ischemic attack [TIA], cerebrovascular accident [CVA], peripheral embolism) have undergone percutaneous PFO closure with 5 different devices. There were 30 women and 50 men, with a mean age of 52+/-12 years. Sixty patients had only a PFO, whereas 20 patients had both a PFO and an atrial septal aneurysm. The implantation procedure was successful in 78 patients (98%). During 5 years of follow-up (mean, 1.6+/-1.4 years; range, 0.1 to 5.0 years), the actuarial annual risk to suffer a recurrent thromboembolic event was 2.5% for TIA, 0% for CVA, 0.9% for peripheral emboli, and 3.4% for the combined end point of TIA, CVA, or peripheral embolism. A postprocedural shunt was a predictor of recurrent paradoxical embolism (RR, 4.2; 95% CI, 1.1 to 17.8; P=0.03). The risk for recurrent thromboembolic events in patients with both atrial septal aneurysm and PFO was not significantly increased compared with patients with only PFO (RR, 1.0; 95% CI, 0.2 to 4.7; P=0.95).

CONCLUSIONS

Percutaneous PFO closure appears to be a promising technique in the prevention of recurrent systemic thromboembolism in patients with a PFO after a first event. Prospective studies comparing percutaneous PFO closure with antithrombotic medications or surgery must define its therapeutic value.

Adapting the Jalowiec Coping Scale in Norwegian adult psoriasis patients

The aim of the present study was to adapt the Jalowiec Coping Scale (JCS) to accommodate adult patients with psoriasis. The sample comprised 334 patients who were treated consecutively at three dermatology departments in the eastern Norway. A total number of 273 hospitalised patients (20%) and out-patients (80%) completed the questionnaire, yielding a response rate of 82%. The study assessed the reliability and the face, content and construct validity of the Norwegian version of the JCS. In addition, researchers investigated the most frequently used/effective coping strategies, the relationships between demographic/clinical variables, self-reported physical symptoms and the use of coping strategies. The results (correlational coefficients and interitem alpha s) indicated that there was an overlap in substantive content among the original JCS subscales, due either to measurement error (bias or response style) and/or because the patients in the present study were in a demanding situation in relation to their disease, which may have activated a variety of coping strategies. A factor analysis resulted in a three-factor solution (confrontive problem-solving, normalising/optimistic and combined emotive) with satisfactory internal consistency. This factor solution comprised 31 items with an explained variance of 37% of the total pool of items. The most frequently used and effective coping strategies could be labelled as emotion-focused (optimistic/maintain control). Significant correlations were found between age, hospital setting, self-reported physical symptoms and different coping subscales. However, further studies are needed to assess the validity and reliability of the JCS among different population groups in Norway.

Coping and quality of life in patients with psoriasis

The aim of the present study was to investigate the relationship between coping dimensions and overall quality of life, disability and health status in patients' with psoriasis. Psoriasis is one of several chronic diseases which requires self-management in order to ensure an enhanced quality of life. The sample comprised 334 patients who were treated consecutively at three dermatology departments in eastern Norway. A total number of 273 patients completed the questionnaire, yielding a response rate of 82% (20% in-patients and 80% out-patients). The following questionnaires were used: The Jalowiec Coping Scale, the Psoriasis Disability Index, the Quality of Life Scale, and the SF-36. Results showed that patients who used combined emotive coping strategies reported more disability, poorer mental health and worse overall quality of life. Furthermore, patients who more frequently used normalising/optimistic coping reported higher levels of mental health. However, the variance explained by coping effort was low to moderate. Coping explained the variance in mental health and overall quality of life to a greater extent than that in physical health. Knowledge about the relationships between coping and quality of life dimensions is important with regard to the establishment and implementation of appropriate psychosocial interventions for patients with psoriasis.

The relationship between demographic and clinical variables, and quality of life aspects in patients with psoriasis

There is a strong need for health care programmes to promote functioning and quality of life in patients suffering from psoriasis. The aim of the present study is to highlight the relationships between demographic and clinical variables and disease-specific disability, health status, the perception of living with a chronic disease and the overall quality of life in patients suffering from psoriasis. A further aim is to examine the extent to which the effects of demographic and clinical variables on mental health and the overall quality of life are mediated by disability, physical health and the perception of living with psoriasis. The sample examined in this study comprised 334 patients (20% in-patients and 80% out-patients) who were treated consecutively at three dermatology departments in eastern Norway. A total of 282 patients completed the testing procedures, yielding a response rate of 85%. The following questionnaires were used: The Psoriasis Disability Index, the Sf-36 and the Quality of Life Scale. Correlation and multiple linear regression analyses were performed to address the core issue. Results show that demographic and clinical variables combine to explain variance in health status, the perception of living with psoriasis and overall quality of life. While most of the variance is explained by the clinical variables, the disease-specific disability variable seems to be an important mediating factor.

The Norwegian version of the Quality of Life Scale (QOLS-N). A validation and reliability study in patients suffering from psoriasis

The aim of this study was to adapt, validate, and test for reliability the Quality of Life Scale in Norwegian (QOLS-N) for patients suffering from psoriasis. Two hundred and eighty-two patients with psoriasis were included in the study. Self-reported health was measured using the SF-36. Disease severity was also measured in 95 patients using the Psoriasis Area and Severity Index (PASI). The reliability of the QOLS-N was computed using the internal consistency reliability (Cronbach's alpha) and the test-retest reliability test. Face and content validity and construct discriminant ability of the QOLS-N were assessed. The results indicated that the QOLS-N has highly satisfactory rates of test-retest reliability (r = 0.83) and internal consistency reliability (alpha 0.86). As expected, the QOLS-N had a lower correlation with physical health (r = 0.24, p < 0.000) and self-reported symptoms (r = -0.20, p < 0.001), and a higher correlation with mental health (r = 0.52, p < 0.000). The correlation with disease severity was not significant (-0.06). The results reported in the present paper are in accordance with those derived in other validation studies. The QOLS-N seems to be a reliable and valid measure of global quality of life in patients suffering from psoriasis.

[Pathophysiology of coronary collateral circulation in the human]

The functional relevance of coronary collaterals in humans has yet to be fully explored. Several studies demonstrated a protective role of collaterals in patients with coronary artery disease. On the other hand, negative aspects of well-developed coronary collaterals have been reported, e.g. a higher rate of restenosis following coronary angioplasty, or a redistribution of blood via collaterals away from the myocardial area in need towards normally perfused areas (coronary steal). In the past, the coronary collateral circulation has been assessed only qualitatively, using visual angiographic or nuclear imaging methods. With the recent advent of intracoronary Doppler and pressure-transducers, quantitative assessment of functional parameters of the coronary circulation has become feasible. This article reviews ongoing research in the field of coronary collaterals in humans, concerning their exact determination, the positive and negative aspects of their structure as well as their functional aspects.

Extracellular dopamine and catabolites in rat striatum during lactic acid perfusion as determined by in vivo microdialysis

Many experimental studies concerning hypoxia or ischemia have reported a decrease in intra/extracellular pH and massive dopamine (DA) release in the striatum. The present work investigated whether the increase in striatal extracellular DA is related to acidification or to lactate production. Striatal perfusion of lactic acid (pH 5.5) by microdialysis in conscious freely-moving rats induced an increase in extracellular concentrations of DA and catabolites, homovanillic acid (HVA) and 3,4-dihydroxyphenylacetic acid (DOPAC), as a probable result of acidification. Perfusion with sodium lactate (pH 7.4) failed to modify DA and catabolite release, whereas orthophosphoric acid produced the same effect as lactic acid. As lactic acidosis is known to induce a displacement of iron from its uptake sites, the possible role of this metal in response to acidosis was studied by perfusing ferrozine, an iron complexing agent, at the same time as lactic acid. The results showed that ferrous ions are involved in the process and suggested that oxygen free radicals play a role in the extracellular release of DA. Thus, lactic acid perfusion in rat striatum would appear to be a useful model for in vivo studies of the mechanisms responsible for increases in extracellular DA during hypoxia and ischemia.

Poisoning with methanol and ethylene glycol:1H NMR spectroscopy as an effective clinical tool for diagnosis and quantification

Analysis of serum and urine samples from three patients in a metabolic acidotic state was performed using biochemical methods and proton nuclear magnetic resonance (1H NMR). Methanol and ethylene glycol were identified by their singlet peaks in the 1H NMR spectra recorded directly from 0.5 ml of the collected samples. Quantification of these compounds was obtained simultaneously with that of their metabolites, formate and glycolate respectively and of lactate and ethanol, the latter being used as an antidote. The NMR results were found to be very similar to the biochemical findings. The results presented here suggest that 1H NMR can be clinically useful since it quickly provides information on the onset of metabolic acidosis and on the biotransformation of xenobiotics.

The impact of psoriasis on psychosocial life domains. A review

Living with a chronic disease, such as psoriasis, is likely to have psychological as well as social implications. Hence, knowledge about the impact of psoriasis on patients' life situation is important for designing and selecting suitable health care programmes for this group of patients. A review of studies published between 1983 and 1995 shows that there are some common factors as regards the psychological distress and social and functional limitations this group of patients has to deal with. However, it is difficult to compare the findings on the psychosocial impact of psoriasis owing to the differences in methods, study design and patient samples. This suggests that further research is needed. A holistic perspective that includes patients' quality of life may represent a fruitful approach.

Functional assessment of collaterals in the human coronary circulation

The coronary collateral circulation is an alternative source of blood supply to a myocardial area jeopardized by the failure of the stenotic or occluded vessel to provide enough blood flow to this region. Until recently, only qualitative or semiqualitative methods have been available for the assessment of the coronary collateral circulation in humans, such as the patient's history of walk-through angina pectoris, the registration of intracoronary ECG signs for myocardial ischaemia or angina pectoris during coronary occlusion, or coronary angiographic classification (score 0-3) of collaterals. Studies of coronary wedge pressure measurements distal of a balloon-occluded coronary artery and the recent advent of ultrathin pressure and Doppler angioplasty guidewires have made it possible to obtain pressure or flow velocity data in remote vascular areas and, thus, to calculate functional variables for coronary collateral flow. Those coronary occlusive pressure- and flow velocity-derived parameters express collateral flow as a fraction of antegrade coronary flow during vessel patency of the collateral-receiving vessel. They are both interchangeable, and they have been validated in comparison to 'traditional' methods and against each other. The possibility of accurately measuring coronary collateral flow indices in humans undergoing coronary balloon angioplasty opens areas of investigation of the pathogenesis, pathophysiology and therapeutic promotion of the collateral circulation previously reserved for exclusively experimental studies. The purpose of this article is to review several clinically available methods for the functional characterization of the coronary collateral circulation.

Effects of size and sequence on the iontophoretic delivery of oligonucleotides

Adequate cellular availability of synthetic oligonucleotides is crucial to their success as therapeutic agents. These compounds, however, are not expected to be orally active. This has led to interest in a variety of alternate drug delivery methods, including iontophoretically enhanced transdermal delivery. The purpose of this work is to begin characterizing the structure-activity relationship for iontophoresis of oligonucleotides through the skin. The in vitro permeation of 16 biologically relevant phosphorothioate oligonucleotides across hairless mouse skin was studied. Oligonucleotides with less than 20 bases (n = 10) had a wide range of steady-state flux levels (2.1-26.2 pmol/ cm2 h). A lower flux differential was observed for compounds ranging from 20 to 40 bases long (1.2-2.2 pmol/cm2 h). For the smaller compounds, transport, in general, decreased with increasing size; however, there were several oligonucleotides that did not follow this pattern. These data indicate that factors other than size influence transport and that the impact is greater at shorter lengths. Differential penetration between equal sized oligonucleotides synthesized with identical bases in reversed order indicates that sequences and not simply base composition affects steady-state flux across skin. Molecular structure, therefore, is a key contributor to iontophoretically assisted transport. Further studies are necessary to develop more precise predictions about the relationship between oligonucleotide structure and transdermal delivery.

1H-NMR analysis of trimethylamine in urine for the diagnosis of fish-odour syndrome

This paper reports the use of proton NMR spectroscopy for the analysis of trimethylamine in the urine of a patient with trimethylaminuria. Analysis of this compound was also performed for other members of his family. Qualitative and quantitative determination of trimethylamine and trimethylamine-N-oxide was simultaneously performed on untreated urine within a few minutes. The application of the method is discussed.

[Chemical and biological studies on Taxol (Paclitaxel) and Taxotere (Docetaxel), new antineoplastic agents]

Since the discovery of Taxol and of its antitumor activity a number of chemical, pharmacological and clinical studies have been performed on this natural diterpene isolated from the genus Taxus. Because the extraction of Taxol from the bark is expensive, difficult and damaging to the Taxus species, alternative sources have been studied. To date, one of the most promising alternatives is the semisynthesis of Taxol from 10-deacetylbaccatin III, a renewable precursor found in the needles of the European yew tree, Taxus baccata. From this natural compound, a number of new active compounds bearing different substituents at carbons 2, 4, 5, 7, 10, 13, 2' and 3' have been prepared. Among the new substances, Taxotere (N-debenzoyl-N-tert-butoxycarbonyl-10-deacetyltaxol) was found to be one of the most potent in its interaction to the cellular target of antitumor taxoids: tubulin. The chemistry and structure-activity relationships of the antitumor taxoids are presented.

Numerical chromosome anomalies after fertilization of freeze-thawed mouse oocytes

The chromosome complement of first cleavage stage mouse embryos was analyzed to investigate the effect of slow freezing-fast thawing cryopreservation on chromosome numbers by comparing these numbers with those found fresh after fertilization of control oocytes. Fewer frozen-thawed (34.1%) than control oocytes (75.0%) cleaved to the 2-cell stage after in vitro fertilization. The incidence of hyperploidy was significantly increased by freezing (4.5% vs. 0% in controls). Polyploidy was not significantly affected (17.0% for freeze-thaw embryos vs. 26.2% for controls).