A wise person plants a tree a day before the end of the world: coping with the emotional experience of climate change in Poland

It is now widely accepted that we are in a climate emergency, and the number of people who are concerned about this problem is growing. Yet, qualitative, in-depth studies to investigate the emotional response to climate change were conducted either in high-income, western countries, or in low-income countries particularly vulnerable to climate change. To our knowledge, there are no qualitative studies conducted in countries that share great barriers to decarbonization while being significant contributors to carbon emissions. Since climate change affects people globally, it is crucial to study this topic in a variety of socio-political contexts. In this work, we discuss views and reflections voiced by highly concerned residents of Poland, a Central European country that is a major contributor to Europe's carbon emissions. We conducted 40 semi-structured interviews with Polish residents, who self-identified as concerned about climate change. A variety of emotions related to climate change were identified and placed in the context of four major themes: dangers posed by climate change, the inevitability of its consequences, attributions of responsibility, and commonality of concern. Our findings highlight a variety of often ambivalent and conflicting emotions that change along with the participant's thoughts, experiences and behaviours. Furthermore, we describe a wide repertoire of coping strategies, which promoted well-being and sustained long-term engagement in climate action. As such, our work contributes to research on a broad array of climate-related emotions.

Supplementary Information

The online version contains supplementary material available at 10.1007/s12144-022-03807-3.

Diagnostic yield of cardiac magnetic resonance in athletes with and without features of the athlete's heart and suspected structural heart disease

Background

Cardiac magnetic resonance (CMR) is a second-line imaging test in cardiology. Balanced enlargement of heart chambers called athlete's heart (AH) is a part of physiological adaptation to regular physical activity.

Purpose

The aim of the study was to evaluate the diagnostic utility of CMR in athletes with suspected structural heart disease (SHD) and to analyse the relation between the presences of AH and SHD.

Methods

This retrospective, single centre study included consecutive 154 athletes (57 non-amateur, all sports categories, 87% male, mean age 34±12 years) referred for CMR because of suspected SHD. The suspicion was based on existing guidelines including electrocardiographic and/or echocardiographic changes suggestive of abnormality but without a formal diagnosis. AH was defined as a balanced enlargement of most heart chambers above the reference values in adults with or without mild left ventricular hypertrophy.

Results

CMR permitted to establish a new diagnosis in 66 patients (42%). The main diagnoses included myocardial fibrosis typical for prior myocarditis (n=21), hypertrophic cardiomyopathy (n=17, including 6 apical forms), other cardiomyopathies (n=10) and prior myocardial infarction (n=6). The presence of pathologic LGE was found in 41 patients (27%) and was non-significantly higher in athletes without AH (32% vs. 19%, p=0.08). Junction-point LGE was more prevalent in patients with AH phenotype (22% vs. 9%, p=0.02). Patients without AH tended to be more likely diagnosed with an SHD than those with AH (49% vs. 32%, p=0.05). This was mainly caused by a trend towards a higher prevalence of non-apical hypertrophic cardiomyopathy and prior myocardial infarction in this group.

Conclusions

The inclusion of CMR into the diagnostic process leads to a new diagnosis in many athletes with suspicion of SHD and equivocal routine tests. Athletes with AH pattern are equally likely to be diagnosed with SHD in comparison to those without AH phenotype. It shows that the development of AH and SHD can occur in parallel, which makes differential diagnosis in this group of patients more challenging.

Funding Acknowledgement

Type of funding sources: None.

Identify cause of heart failure of unknown aetiology using cardiac magnetic resonance - a 10-year observational study

Funding Acknowledgements

Type of funding sources: None.

Background

Heart failure (HF) is a clinical syndrome caused by structural or functional cardiac abnormality and is diagnosed on the basis of typical symptoms. It is associated with significant morbidity and mortality and affects more than 25 million people worldwide.

HF of unknown aetiology is managed with symptomatic treatment. Patients with reduced (HFrEF) or mid-reduced ejection fraction (HFmrEF) and no clear cause of systolic dysfunction are usually classified as having DCM. In HFpEF group ejection fraction is preserved but diastolic dysfunction is present leading to HF symptoms.

Purpose

The aim of this study was to investigate the clinical significance of cardiac magnetic resonance (CMR) imaging to identify heart failure (HF) aetiology.

Methods

We retrospectively reviewed all medical charts of patients referred for CMR due to heart failure of unknown aetiology admitted to our hospital between 2008 and 2017. Only patients with no specific pre-CMR initial diagnosis were included. Patients with suspicion of any specific disease leading to HF were excluded. If a referring physician suspected myocarditis, cardiomyopathy, previous myocardial infarction or advanced stable coronary disease (based on clinical signs and symptoms, the patient’s and family history or all pre-CMR studies), these patients were omitted from our analysis. Thus, we included only patients whose diagnostic work-up did not reveal suspicion of any specific cardiac disease leading to HF.

Results

The study sample consisted of 243 patients (173 (71.2%) male, mean age 44.0 ± 14.2%). All patients underwent contrast-enhanced CMR. Late gadolinium enhancement (LGE) was detected in 74.9% cases. Cardiomyopathies comprised the main aetiology (174 cases, 71.6%), in particular dilated cardiomyopathy (143 patients, 58.8%). 17 patients (7.0%) were diagnosed with myocarditis and in 24 patients (9.9%) CMR-based diagnosis was ambiguous – pointing out myocarditis or dilated cardiomyopathy. In 23 cases (9.5%) CMR indicated the presence of prior infarction undetected by pre-CMR testing. In five patients (2.1%) valvular disease was revealed as the sole cause of HF.

We analysed the change in patients’ management guided by the CMR results defined as change of treatment and/or necessity of further tests leading to therapeutic consequences. Change of pre-CMR diagnosis occurred in 94 patients (38.7%) and was judged crucial in 41 patients (16,9%).

As crucial we adjudicated the diagnosis associated with a need immediately further investigation and treatment changing, as follows: newly diagnosed amyloidosis, ischaemic heart disease or complex advanced valvular disease and cardiomyopathies other than dilated, hypertrophic and restrictive.

Conclusion

Our study strongly suggests that cardiac magnetic resonance imaging is a valuable tool for determining the aetiology of heart failure and impacts patients" management.

Abstract Figure.

P825 Multi-modality imaging for noninvasive diagnosis of transthyretin amyloid cardiomyopathy-single centre experience

Background

Thransthyretin amyloidosis (ATTR) is a rare progressive disease that may present as heart failure with preserved ejection fraction, severe aortic stenosis, hypertrophic cardiomyopathy (HCM) or resctrictive cardiomyopathy. There are two types of ATTR: hereditary ATTR (hATTR) caused by mutations in the TTR gene and wild-type ATTR (wtATTR) resulting from deposition of wild-type TTR protein.

Purpose

We describe the clinical heterogeneity of ATTR patients from our centre diagnosed noninvasively in 2018-2019.

Methods

All patients presented intensive cardiac uptake at 99mTc-DPD scintigraphy. Light chain amyloidosis was excluded.

Results

8 patients were diagnosed with ATTR (Table 1). Three unrelated male patients were diagnosed with hATTR due to rare mutations: 2 of them had Phe33Leu, 1 patient had Glu89Lys mutation. Five

patients (males) were diagnosed with wtATTR. Age of onset differed among the patients. Characteristic clinical features included cardiomyopathy with increased left and right ventricular wall thickness. Only 2 patients had restrictive filling pattern, 3 patients had atrial fibrillation. Laboratory examination showed increased level of troponin T and NT-proBNP. Three patients had bilateral carpal tunnel syndrome. Thanks to DPD-scintygraphy we excluded ATTR in two patients with false-positive results of histological exam for TTR-related amyloid deposits.

Conclusions

Although ATTR is known for its broad clinical spectrum, patients from our center presented mostly as HCM phenocopies but in different stages of heart failure. Appropriate diagnosis of ATTR is crucial and have direct therapeutic impact. Echocardiography raise the suspicion of amyloid cardiomyopathy, while other imaging technique (DPD-scintigraphy) confirm it or exclude it in noninvasive way.

Patient 1 2 3 4 5 6 7 8 Mutation Glu89Lys Phe33Leu Phe33Leu wild type wild type wild type wild type wild type Sex male male male male male male male male Age of onset 57 56 55 77 78 80 77 76 Electrocardiogram AF low QRS voltage low QRS voltage AF, RBBB LVH LVH pseudoinfarct pattern, low QRS voltage AF, LVH Maximal wall thickness [mm] 23 20 18 28 22 23 18 20 LVEF% 45 40 40 60 65 60 45 55 Asymmetric hypertrophy pattern + - - - + + - + NYHA III II II II III II II II NT-proBNP pg/ml 2122 1200 1500 2755 222 2630 2426 hs-Troponin T ng/l 50 98 42 65 35 63 64

Abstract P825 Figure 1

Clinical Significance of Gastrointestinal Carriage of Klebsiella Pneumoniae-Producing Extended-Spectrum Beta-Lactamases in Kidney Graft Recipients

The burden of Klebsiella pneumoniae (KP) producing extended-spectrum beta-lactamases (ESBL+) urinary tract infections (UTIs) is a growing problem after kidney transplantation (KTX). The study was aimed at evaluating the incidence of KP ESBL+ gut colonization in KTX recipients and its correlation with clinical outcomes with special regard to UTIs. The study included all KTX patients hospitalized in our department between January 2014 and December 2016. During this period 2018 KTX patients were admitted: 605 in 2014, 750 in 2015, and 663 in 2016, respectively. Screening for drug-multiresistant Enterobacteriaceae gut carriage was performed in 104 patients (2014), 122 (2015), and 166 (2016). In 2014, 2015, and 2016, 18 (17.3%), 26 (21.3%), and 30 (18.1%) patients had positive test results, and 44 (42.3%), 36 (29.5%), and 45 (27.4%) KTX patients were diagnosed with KP ESBL+ UTI. In 2014, KP ESBL+ UTI was diagnosed in 30 (34.9%) cases with negative anal swab and in 14 patients (77.8%) with positive test result (P = .0008). In 2015, KP ESBL+ UTI was diagnosed in 21 patients (21.9%) with negative anal swab and in 15 (57.7%) with positive test result (P = .0004). In 2016, KP ESBL+ UTI was diagnosed in 24 patients (17.8%) with negative anal swab and in 21 (72.4%) with positive test result (P = .000001). In conclusion, we have revealed a strong association between gut K. pneumoniae colonization, female sex, and MPA intake and KP ESBL+ urinary tract infections in kidney transplant recipients. Our results indicate the very important role of KP ESBL+ screening, while strategies of identified carriers require further research.

Systolic myocardial volume gain in dilated, hypertrophied and normal heart. CMR study

AIM

To investigate changes in myocardial tissue volume during the cardiac cycle to verify the hypothesis of non-compressibility of the myocardium in healthy individuals (HI) as well as in patients with hypertrophic cardiomyopathy (HCM), dilated cardiomyopathy (DCM), and aortic stenosis (AS).

MATERIALS AND METHODS

The study group included 30 HI, and patients with HCM (n=110), DCM (n=89), and AS (n=78). Left ventricular (LV) function, end-diastolic, and end-systolic volumes were calculated based on cardiac magnetic resonance imaging (CMR) for all participants.

RESULTS

End-systolic myocardial volumes were higher than end-diastolic in both controls (91.2±26.6 versus 85.1±24.3 ml, p<0.001) and in all patient groups: HCM (214.3±81.6 versus 176±64.2 ml, p<0.01), DCM (128.4±43.1 versus 115.4±42.9 ml, p<0.001) and AS (155.1±37.1 versus 129.4±34.6 ml, p<0.001). HCM and AS patients had significantly higher systolic volume gain than HI (21.5±8.3 versus 10.6±6.3%, p<0.01 and 18.3±5.7 versus 10.6±6.3% p=0.013, respectively). Conversely, DCM patients had lesser increases in myocardial systolic volume than HCM patients (11.2±4.8% versus 21.5±8.3, p=0.01) and AS patients (11.2±4.8% versus 18.3±5.7, p=0.02). No differences were found in systolic volume gain between AS and HCM patients (p=ns) or between DCM patients and HI (p=ns).

CONCLUSION

End-systolic myocardial volume was significantly higher than end-diastolic volume in all subsets of patients. The systolic volume gain was greater in individuals with hypertrophy than in those without.

Prevalence of ankylosing spondylitis in Poland and costs generated by AS patients in the public healthcare system

The aim of the research was to analyse the prevalence of ankylosing spondylitis (AS) in Poland and to assess the costs generated by AS patients in the system of public health care. The database of national payer-National Health Fund (NHF)-has been analysed. For the analysis, the information has been extracted from IT system about each treated patient with ICD-10 = M45 code as main or coexisting diagnosis included in the mandatory reports from entities of public healthcare service. In the years 2008-2013, from 28,800 to 32,800 persons diagnosed with AS as main or coexisting diagnosis have been registered in NHF database. In 2013, the prevalence amounted to 7.48 for 10,000 persons of general population-the highest in Kujawy-Pomerania province (10.92 per 10,000 inhabitants), Silesia (10.04) and Świętokrzyskie province (9.81). In male patients, this coefficient amounted to 8.91 per 10,000 inhabitants, whereas in female-to 6.15. In 2013, the prevalence for men was the highest in the age group of 60-64 years and for women in the group of 65-69 years. The healthcare expenses related to AS financed by the NHF increased from 13,200 million PLN (6.3 million USD) in 2008 to 72,600 million PLN (21,900 million USD) in 2013. The increase in healthcare expenses related to AS patients in the public healthcare system is significant and noticeable. High regional diversity is also a vital issue. It is necessary to carry out further research on the incidence rate of AS in Polish population.

Relationship between Tetracyclines' Structure and Minimal Inhibitory Concentration of Streptococcus spp

During the past years, a growing number of bacterial strains have become resistant to tetracyclines. The problem of increasing resistance and lack of susceptibility to tetracyclines applies to strains isolated from both: animals and humans. Basic tools to design new drugs and determining the direction of the search for new molecules is the analysis of the relationship between the chemical structure and the pharmacokinetic and pharmacodynamic parameters. Purpose of this study is to determine the relationship between physicochemical parameters of tetracyclines and MIC50 and MIC90 values determined for Streptococcus spp. Analysis of physicochemical parameters of selected drugs was made using MarvinSketch 5.11.5 (ChemAxon Ltd.) and QuickProp 3.1 software from Schrödinger package v 31207. MIC50 and MIC90 values were correlated with 51 calculated physicochemical parameters and arithmetic expressions. Internal and external model validation was performed using leave-one out method. 4 arithmetic expressions fulfilled all validation criteria, but only in relation to MIC50. A new method to optimize the tetracyclines' structure in relation to Streptococcus spp. was presented. It was also shown that the relations of structure: antimicrobial activity type can have different nature depending on MIC50 or MIC90 of specific bacterial strain.

PssO, a unique extracellular protein important for exopolysaccharide synthesis in Rhizobium leguminosarum bv. trifolii

Synthesis and secretion of polysaccharides by Gram-negative bacteria are a result of a concerted action of enzymatic and channel-forming proteins localized in different compartments of the cell. The presented work comprises functional characterization of PssO protein encoded within the previously identified, chromosomal exopolysaccharide (EPS) biosynthesis region (Pss-I) of symbiotic bacterium Rhizobium leguminosarum bv. trifolii TA1 (RtTA1). pssO gene localization between pssN and pssP genes encoding proteins engaged in exopolysaccharide synthesis and transport, suggested its role in EPS synthesis and/or secretion. RtTA1 pssO deletion mutant and the PssO protein overproducing strains were constructed. The mutant strain was EPS-deficient, however, this mutation was not complemented. The PssO-overproducing strain was characterized by increase in EPS secretion. Subcellular fractionation, pssO-phoA/lacZ translational fusion analyses and immunolocalisation of PssO on RtTA1 cell surface by electron microscopy demonstrated that PssO is secreted to the extracellular medium and remains attached to the cell. Western blotting analysis revealed the presence of immunologically related proteins within the species R. leguminosarum bv. trifolii, bv. viciae and Rhizobium etli. The secondary structure of PssO-His(6), as determined by FTIR spectroscopy, consists of at least 32% alpha-helical and 12% beta-sheet structures. A putative function of PssO in EPS synthesis and/or transport is discussed in the context of its cellular localization and the phenotypes of the deletion mutant and pssO-overexpressing strain.

The influence of acute progressive hypoxia on bioelectrical activity of the brain

Hypoxia, a noxious and hyperventilatory stimulus and a modifier of neuronal metabolism, could influence cortical function. In this study we attempted to assess any such influence, its determinants, and particularly the role in it of the accompanying hypoxic emotional distress. We addressed the issue by examining the associations among EEG, ventilation, and anxiety during progressive poikilocapnic hypoxia (end-point SaO(2) approximately 75%) in 12 awake healthy volunteers (mean age 27.5 +/-0.7 yr). All subjects hyperventilated in response to hypoxia and 3 of them had a high level of anticipatory anxiety that forced one person to discontinue the test. We failed to show any major effect of hypoxia on the EEG pattern analyzed by visual inspection or wavelet power spectra. Therefore, no relationship between the ventilatory and cortical activity responses to hypoxia could be established. Cortical activity changes appeared, however, in the subjects who experienced emotional distress during the test. These changes were apparent on an expanded analysis of the EEG signal by the use of the Lempel-Ziv complexity that takes into account the ordering of variations in the signal, rather than only the relative frequency of events analyzed by the Shannon entropy. The Lempel-Ziv complexity offers promise as a novel method for unraveling fine and otherwise unexpressed alterations in cortical bioelectrical activity.

Neurotransmitter mechanisms in the enhancement of the hypoxic ventilatory response by antecedent hyperoxia in the anesthetized rat

A brief period of antecedent oxygen breathing enhances the ventilatory response to hypoxia. The mechanisms of this phenomenon are uncertain and have been variably linked to the central glutamatergic or nitrergic pathways. In the present study we put a question of how blockade of either neurotransmitter pathway would compare with the concurrent blockade of them both in terms of the enhancement of posthyperoxic hypoxic ventilation. The study was performed on the anesthetized, vagotomized, spontaneously breathing rats divided into the following experimental groups: control NaCl-treated, glutamate blocker 2-amino-5-phosphonopentanoic acid (AP5)-treated, nitric oxide synthase blocker 7-nitroindazol (7NI)-treated, and AP5+7NI-treated. The protocol consisted of measuring the ventilatory response to 12% O2, a steady- state poikilocapnic hypoxia, undertaken in three consecutive conditions in each animal: the initial control, 25 min after injection of a given chemical agent, and then after a 15-min period of oxygen breathing. Respiration was evaluated from the diaphragmatic EMG signal. We found that the posthyperoxic hypoxic ventilatory enhancement was but partially dampened by either AP5 or 7NI. Concurrent administration of the two blockers further diminished, but did not abolish, the hypoxic ventilatory enhancement. We conclude that although the glutamate-NO system accounts for an appreciable part of the posthyperoxic hypoxic ventilatory enhancement, other, as yet unclear, mechanisms contribute as well. These mechanisms may be worth exploring given the substantial enhancing effect the antecedent oxygen has on hypoxic hyperventilation.

Stability of ascorbyl palmitate molecule in the rat brain

Recent investigations have shown the ability of ascorbyl palmitate (AP), a bioactive, lipid-soluble ester of ascorbic acid (AA), to penetrate neural tissues. This study seeks to determine the occurrence of hydrolysis of AP molecule in brain tissue, which could rather point to the action of AA alone carried over the biological barrier and then released from the AP compound. The integrity of AP molecule was examined qualitatively in the rat brain by thin-layer-chromatography. AP was injected into an internal carotid artery in a dose of 75 mg per rat after tying off the common and external carotid arteries at the same side. The rats were sacrificed 15 min later, the brain tissue was extracted with chloroform/methanol and chromatographed. The AP bands plated from the samples ipsilateral to the injection side strictly corresponded to the AP standard's location and were clearly separated from the AA standard with no overlap. The experiment showed that AP resists hydrolysis in the brain and thus the short-term biological effects of AP may be ascribed to the action of an intact ester molecule. The results may help elucidate the biological action of AP, a compound that increasingly attracts attention for biomedical use due to its antioxidant potential and ability to penetrate into the membrane signaling target sites.

The aging carotid body

The respiratory system is subject to the aging process, which could limit its responsiveness to hyperventilatory stimuli. Attenuation of the ventilatory response to hypoxia in old age is, as yet, an unresolved issue. Such attenuation may be germane for the pathogenesis of respiratory disorders developing more often in elderly subjects. The aim of this study was to determine the potential adverse effects of age on the morphology and function of carotid bodies. Morphology was studied at the level of electron microscopy on carotid bodies dissected from adult young (3 months) and old (>2 years) rats and function by comparing the hypoxic ventilatory response in populations of young (mean age 24 years) and old (mean age 71 years) female subjects. The human protocol consisted of a progressive hypoxia test, based on a rebreathing technique in a closed system. The hypoxic ventilatory response was evaluated from the slopes of minute ventilation on arterial oxygen saturation. The results of the morphological study showed degenerative changes developing with age in the ultrastructure of carotid bodies. On the other side, respiratory responses to hypoxia in old women were well preserved and were no less than those in young women. Therefore, a discrepancy appeared between the morphological and functional aspects. These findings suggest development of compensatory mechanisms in brain respiratory areas which maintain primary defensive reflexes, such as the hyperventilation of hypoxia.

Hypoxic ventilatory profile in the anesthetized rat

In the present study we investigated whether hypocapnia that accompanies hypoxic hyperventilation might affect the biphasic, stimulatory/depressant, ventilatory response to hypoxia. The experiments were carried out in anesthetized, vagotomized, spontaneously breathing, and poikilocapnic rats. The animals were subjected to acute steady-state hypoxia consisting of 12% O(2) in N(2) in inspiratory mixture. Ventilation and its frequency and volume components were assessed from the integrated electromyographic activity of the diaphragm. We found that despite the development of significant hypocapnia, the hypoxic ventilatory response consisted of rapid stimulation followed by a gradual decline. The frequency component contributed more to the ventilatory increase than that of volume. The results indicate that the hypoxic ventilatory profile in the anesthetized poikilocapnic rat resembles that known to be present during isocapnia. We conclude that hypocapnia neither hampers the hypoxic ventilatory reactivity nor alters the biphasic hypoxic ventilatory profile. These observations may aid planning experimental rat model studies.

Increased local vascular endothelial growth factor expression associated with antitumor activity of proteasome inhibitor

Inhibition of the proteasome, a multicatalytic proteinase complex, is an attractive approach to cancer therapy. Here we report that a selective inhibitor of the chymotrypsin-like activity of the proteasome, PSI (N-benzyloxycarbonyl-Ile-Glu(O-t-butyl)-Ala-leucinal) may inhibit growth of solid tumors not only through apoptosis induction, but also indirectly--through inhibition of angiogenesis. Two murine tumors: colon adenocarcinoma (C-26) and Lewis lung carcinoma (3LL) were chosen to study the antitumor effect of PSI. In an in vivo model of local tumor growth, PSI exerted significant antitumor effects against C-26 colon carcinoma, but not against 3LL lung carcinoma. Retardation of tumor growth was observed in mice treated with both 10 nmoles and 100 nmoles doses of PSI and in the latter group prolongation of the survival time of tumor-bearing mice was observed. PSI inhibited angiogenesis in the C-26 growing tumors with no such effect in 3LL tumors. Unexpectedly, that activity was associated with upregulation of vascular endothelial growth factor (VEGF) at the level of mRNA expression and protein production in C-26 tumors treated with PSI. C-26 cells treated with PSI produced increased amounts of VEGF in vitro in a dose- and time-dependent manner. We demonstrated that in C-26 colon adenocarcionoma higher VEGF production may render endothelial cells susceptible to the proapoptotic activity of PSI and is associated with inhibition of tumor growth.

Oxygen breathing and ventilation

We investigated the ventilatory response to normobaric poikilocapnic hyperoxia in healthy subjects. The study was carried out in 26 subjects of the mean age 26 +/- 0.9 (SE) years, who breathed pure oxygen through a two-way valve for 10 min. The subjects were in the sitting position with a mouthpiece and nose clip attached. Ventilatory flow was recorded using a pneumotachograph and minute ventilation was calculated from the tidal and frequency components. The SaO(2) and alveolar CO(2) tension were continuously monitored. Ten of the same subjects constituted a control group in which room air was substituted for oxygen and the tests repeated in the same way at another occasion. We found that oxygen breathing caused a transient 8.4% decline in ventilation, whose nadir was 1 min after the introduction of oxygen. Thereafter, ventilation increased significantly above the baseline value and showed a further rising tendency toward the end of the test. We conclude that acute oxygen treatment is unlikely to have a major inhibitory effect on the carotid body-dependent ventilatory drive in normal subjects. The determinants of the hyperoxic ventilatory stimulation remain to be established in further studies.

Ascorbic Acid Enhances Hypoxic Ventilatory Reactivity in Elderly Subjects

The reducing properties of ascorbic acid in the carotid body make it a likely modifier of hypoxia-sensing mechanisms. This open-label study aimed to determine the effect of ascorbic acid on the hypoxic ventilatory response (HVR) in a population of elderly women, in whom both hypoxic reactivity and ascorbic acid levels may be deficient. We examined the HVR to progressive eucapnic hypoxia in 18 healthy females aged 60-80 years, before and after 10 days' ascorbic acid supplementation, given as a sustained release preparation of 1 g twice daily. Respiratory variables were recorded breath by breath, and hypoxic sensitivity was assessed from the linear slopes of minute ventilation and mouth occlusion pressure plotted against oxygen saturation. We found that ascorbic acid increased the HVR by a mean of 44%, this effect being driven by a higher occlusion pressure. We conclude that augmentation of hypoxic reactivity by ascorbic acid may have therapeutic potential in pathologies associated with hypoxia, which frequently develop in old age.

Cortical activity during hypoxic hyperventilation

This study seeks to determine the pattern of electroencephalogram changes during stimulatory ventilatory responses to acute progressive hypoxia. Electroencephalograms were recorded in the 10-20 electrode system during progressive poikilocapnic hypoxic tests based on the rebreathing routine. Healthy subjects were used for he study. A major finding was that hypoxia decreased the power spectra of the alpha activity. The decrease was surprisingly rapid and greater at mild hypoxic desaturation when pulmonary ventilation was about to pick up than during the maximum hypoxic hyperventilation. The possible relation of hypoxic decline in brain bioactivity to the manifestation of hypoxic hyperventilation remains to be elucidated in further studies.

Ventilatory response to hypoxia in elderly women

BACKGROUND

The respiratory system is subject to the ageing process, which could limit its responsiveness to stimuli. Attenuation of the ventilatory response to hypoxia in old age is, as yet, an unresolved issue. Such attenuation may be germane to the pathogenesis of hypoxic respiratory disorders developing more often in elderly subjects.

AIM

The study seeks to determine the potential adverse effects of age on the hypoxic ventilatory response by comparing this response in groups of elderly and young female subjects.

SUBJECTS AND METHODS

Nineteen healthy women of the mean age of 71+/-1.3 (SE) years and 16 women in their twenties were required to perform a progressive isocapnic hypoxic test, based on the rebreathing technique. The ventilatory response was evaluated from the slopes of minute ventilation and mouth occlusion pressure, an index of inspiratory neuromuscular drive, against arterial oxygen saturation. The breathing pattern components also were measured with the breath-by-breath routine.

RESULTS

Ventilatory response to hypoxia averaged 0.65+/-0.10 L/min/% SaO(2) and neuromuscular output was 0.012+/-0.002 kPa/% SaO(2) in the elderly women and these slopes were not reduced compared with those in the young. Nor did the ventilatory slopes relate to age in the older subjects. Baseline breathing pattern was modified in the elderly in that the mean inspiratory flow was significantly higher, but it reached the same stimulated level as that in the young.

CONCLUSIONS

Ventilatory response to hypoxia is independent of age in healthy women. Thus, functional sensitivity of the respiratory control mechanisms does not attenuate with age.

Antitumor activity of tributyrin in murine melanoma model

Butyric acid has been known to inhibit growth and to induce differentiation of a variety of tumor cells. Butyrate-treated tumor cells have also been observed to undergo apoptosis. Although butyrate compounds have demonstrated antitumor activity in murine tumor models and have already been admitted to clinical trials in tumor patients, the exact mechanism of their antitumor effects has not been elucidated. The results of our study showed antitumor activity of tributyrin, a butyric acid prodrug, in murine melanoma model and are strongly suggestive that antiangiogenic effects could participate in antitumor effects of butyrate compounds in vivo.

Synergistic antitumor effects of a selective proteasome inhibitor and TNF in mice

The ubiquitin-proteasome pathway is becoming an attractive target in cancer therapy. The inhibitors of proteasomes have recently been shown to induce apoptosis of tumor cells in vitro and to exert significant antitumor effects in murine tumor models in vivo. Proteasome inhibitors, also prevent NF-kappa B activation. Since this transcription factor is responsible for counteracting apoptosis induced by numerous agents, and proteasome inhibitors have already proved efficacious in increasing the proapoptotic activity of TNF in vitro, we decided to evaluate the antitumor effects of the combined PSI and TNF treatment against a murine C-26 carcinoma. Both agents separately exerted moderate antitumor efficacy. However, their combination proved to exert dramatic antitumor activity with retardation of tumor growth and prolongation of mice survival time. Moreover, 50% of the mice were completely cured by this drug combination. Unexpectedly, there was no potentiation of the cytostatic/cytotoxic effects of these drugs in in vitro assays which argues against the direct influence on C-26 cells. Similarly, the influence of these drugs on tumor induced angiogenesis does not seem to explain the observed antitumor effects. Further studies are necessary to explain the striking antitumor effects of the PSI and TNF combination.

[Local parabulbar anesthesia with Greenbaum cannula for most common ophthalmic operations]

PURPOSE

To compare two methods of local anesthesia in ophthalmic surgery: classic retrobulbar and new--parabulbar made with Greenbaum cannula and to try to assess new method.

MATERIAL AND METHODS

300 patients underwent most common ophthalmic operations: ECCE + PCLI and glaucoma surgery. 150 of them were anesthetised by retrobulbar and 150 by parabulbar (flush) with Greenbaum cannula methods. We compared the presumed influence of these two types of anesthesia on the operations assessing the following: the occurrence "vis a tergo" and posterior capsule rupture. We compared also efficacy of both methods (analgesia and akinesia) and complications (retrobulbar hematoma, globe perforation). We minimalized the volume of anesthetic mixture used in retrobulbar method to 1.5 ml (0.5 ml 0.5% bupivacaine + 1 ml 2% xylocaine).

RESULTS

The number of complications was lower in the group anesthetised by parabulbar method. The complications of local anesthesia were bigger in retrobulbar method (retrobulbar hematoma, globe perforation). Anesthesia in parabulbar method in spite of little volume of anesthetic mixture was very good but akinesia--slightly weaker comparing to retrobulbar injection.

CONCLUSIONS

Parabulbar anesthesia made with Greenbaum cannula is a very good, safe method giving very good anesthesia no possibility of globe perforation or retrobulbar hematoma, but the method is for skilled surgeons because of weaker akinesia.

Interleukin 12 and indomethacin exert a synergistic, angiogenesis-dependent antitumor activity in mice

Nonsteroidal anti-inflammatory drugs have been shown to reduce the incidence and mortality from colorectal cancer. It has recently been demonstrated that these drugs are capable of suppressing the production of pro-angiogenic factors from tumor cells. The mechanisms of antitumor action of interleukin 12 include the enforced secretion of anti-angiogenic factors and stimulation of antitumor immunity. Therefore, we hypothesized that the combination of a model nonsteroidal anti-inflammatory drug--indomethacin and interleukin 12--would result in enhanced angiogenesis-dependent antitumor effects against a colon-26 carcinoma cells transplanted into syngeneic mice. As expected the combined administration of both agents simultaneously resulted in a strengthened antitumor activity that was manifested as a retardation of tumor growth and prolongation of mouse survival. Importantly some mice were completely cured after the combined treatment. As administration of interleukin 12 and indomethacin resulted in enhanced inhibition of angiogenesis it seems possible that prevention of new blood vessel formation is one of the mechanisms responsible for the observed antitumor effects.

Potentiated antitumor effects of interleukin 12 and matrix metalloproteinase inhibitor batimastat against B16F10 melanoma in mice

The application of antiangiogenic agents in cancer therapy has been studied extensively. Combination of agents with antiangiogenic properties could possibly enhance antitumor effects. Interleukin 12 is a cytokine with potent antitumor activity mediated also via antiangiogenic mechanisms. These effects are attributed to IFN-gamma production stimulated by IL-12. Since IFN-gamma has been reported to augment antitumor effects when combined with one of the metalloproteinase inhibitors--batimastat (BB-94), we have examined a combined treatment with IL-12 and BB-94 in a murine melanoma model. The administration of both agents showed potentiated antitumor activity. Furthermore, we have shown in a tumor-induced angiogenesis model that the combined application of IL-12 and batimastat inhibits the formation of new blood vessels to a greater extent than either agent alone. Our observations show that antiangiogenic effects are at least partly responsible for the enhanced antitumor effects of the combined treatment with IL-12 and BB-94.

Lovastatin and tumor necrosis factor-alpha exhibit potentiated antitumor effects against Ha-ras-transformed murine tumor via inhibition of tumor-induced angiogenesis

Lovastatin, a drug commonly used in the treatment of hypercholesterolemia, has previously been reported to exert potentiated antitumor activity when combined with either tumor necrosis factor-alpha (TNF-alpha), cisplatin or doxorubicin in a melanoma model in mice. Since lovastatin interferes with the function of ras oncogene-encoded (Ras) proteins, we have investigated the antitumor activity of lovastatin and TNF-alpha using a Ha-ras-transformed murine tumor model. In in vitro studies, lovastatin inhibited the growth of cells transformed with Ha-ras oncogene (Ras-3T3 and HBL100-ras cells) more effectively than control NIH-3T3 and HBL100-neo cells. In in vivo experiments, the Ras-3T3 tumor demonstrated significantly increased sensitivity to combined treatment with both lovastatin (50 mg/kg) and TNF-alpha (1 microg/day) compared with either agent alone. Combined treatment with both agents also resulted in greater inhibition of blood-vessel formation. Ras-3T3 tumor cells produced increased amounts of vascular endothelial growth factor (VEGF) and lovastatin effectively suppressed VEGF production by these cells. Our results suggest that lovastatin increases antitumor activity of TNF-alpha against tumor cells transformed with v-Ha-ras oncogene via inhibition of tumor-induced blood-vessel formation.

Apolipoprotein E polymorphism in indigenous Australians: allelic frequencies and relationship with dyslipidaemia

OBJECTIVES

To determine the apolipoprotein E (apoE) allelic frequencies and the effect of apoE genotype on lipid concentrations in indigenous Australian subjects.

DESIGN

Cross-sectional study.

SUBJECTS AND SETTING

155 indigenous Australians (92 women and 63 men) of mean (+/- standard deviation) age 45 +/- 17 years (SD +/- 50) were recruited without regard to history of atherosclerotic disease, in collaboration with community-based health centres in five indigenous communities in south-east Queensland. For comparison, 113 subjects of European descent and similar age distribution from the Brisbane and Gold Coast regions were also studied.

MAIN OUTCOME MEASURES

ApoE allelic frequency; apoE genotype; sex; age; diabetes status; body mass index; history of atherosclerotic vascular disease; and concentrations of total cholesterol, triglyceride, HDL-cholesterol and LDL-cholesterol.

RESULTS

The frequency of the apoE4 allele was found to be significantly higher in the indigenous subjects than in the subjects of European descent (P < 0.001). Among indigenous subjects, those with the apoE4 allele tended to have higher triglyceride concentrations and had significantly lower HDL-cholesterol concentrations than those with the apoE3/3 and 3/2 genotypes.

CONCLUSIONS

ApoE allelic frequency is likely to be one of the cluster of factors contributing to the high cardiovascular mortality of indigenous Australians.

Plasma homocysteine levels in indigenous Australians

OBJECTIVES

To determine plasma homocysteine levels in indigenous Australians living in urban areas, and the relationship of these levels with other risk factors in this population.

DESIGN

Cross-sectional study.

SUBJECTS AND SETTING

365 urban indigenous Australian subjects, 153 men and 212 women, mean (SE) age 42 (1) years, ascertained without regard to history of atherosclerotic disease, in collaboration with community-based health centres in five indigenous communities in south-east Queensland, 1997-1998.

MAIN OUTCOME MEASURES

Plasma homocysteine levels, age, sex, smoking history, metformin therapy, history of atherosclerotic vascular disease, serum creatinine level, red cell folate and serum vitamin B12 levels.

RESULTS

89 subjects (24%) had plasma homocysteine levels 15 mumol/L or above. Homocysteine levels were higher in men than in women (men: 14.4 mumol/L; 95% confidence interval [CI], 13.6-15.2; women: 11.9 mumol/L; 95% CI, 11.4-12.5) (P < 0.001); correlated with age (P < 0.001); higher in current smokers (P = 0.02); higher in subjects taking metformin therapy (P = 0.007); and higher in subjects with a history of atherosclerotic vascular disease (P < 0.001). Homocysteine levels were also correlated with serum levels of creatinine (P < 0.001), red cell folate (P < 0.001), and vitamin B12 (P < 0.001).

CONCLUSIONS

These data indicate that the high plasma levels of homocysteine of Australian indigenous subjects are associated with a history of vascular disease, and correlated with, among other things, smoking, and folate and vitamin B12 nutritional deficiency. These are potentially reversible risk factors, and our data suggest that focusing public health initiatives on these issues may reduce the high prevalence of cardiovascular disease in the Australian indigenous population.

Antitumor effects of the combination immunotherapy with interleukin-12 and tumor necrosis factor alpha in mice

There is strong evidence that antitumor activity of interleukin-12 (IL-12) in vivo is mediated, in part, through interferon (IFN gamma) produced by IL-12-stimulated natural killer and T cells. Since IFN gamma and tumor necrosis factor alpha (TNF alpha) have been reported to synergize in antitumor effects in a number of models, we decided to examine whether the combined treatment with recombinant mouse IL-12 and recombinant human TNF alpha would produce similar effects. The efficacy of the combined IL-12/TNF alpha immunotherapy was evaluated in three tumor models in mice: B16F10 melanoma, Lewis lung (LL/2) carcinoma and L1 sarcoma. Intratumoral daily injections of 1 microgram IL-12 in combination with 5 micrograms TNF alpha into B16F10-melanoma-bearing mice resulted in a significant retardation of the tumor growth as compared with that in controls and in mice treated with either cytokine alone. Similar effects were obtained using 0.1 microgram IL-12 and 5 micrograms TNF alpha in LL/2 carcinoma and L1 sarcoma models. Antitumor activity against L1 sarcoma was still preserved when TNF alpha at a low dose (1 microgram) was combined with 0.1 microgram IL-12 and applied for a prolonged time. Potentiation of antitumor effects, which was observed in IL-12/TNF alpha-based immunotherapy, could result from at least three different mechanisms, partly related to stimulation of IFN gamma and TNF alpha production in treated mice: (a) direct cytostatic/cytotoxic effects on tumor cells, (b) induction of antitumor activity of macrophages, and (c) inhibition of blood vessel formation in the tumor. Our studies demonstrate that combination tumor immunotherapy with IL-12 and TNF alpha may be more effective than single-cytokine treatment, and suggest possible mechanisms by which IL-12 and TNF alpha may exert potentiated therapeutic effects against locally growing tumors.

Interleukin-12 inhibits angiogenesis induced by human tumor cell lines in vivo

Tumor cell-induced angiogenesis, i.e., new blood vessel formation within tumor tissue, is an essential requirement for the growth of solid neoplasms. Interleukin-12 (IL-12) inhibits growth of a variety of experimental tumors in vivo. We tested whether antitumor activity of IL-12 is related to the inhibition of angiogenesis induced by tumor cell lines. Angiogenesis was induced in x-ray immunosuppressed Balb/c mice by intradermal injection of the following human tumor cells: T47D, originating from mammary carcinoma; A431, derived from vulval carcinoma; and Skv, established from bowenoid papulosis, Systemic treatment of the mice with murine IL-12 significantly decreased angiogenesis induced by human tumor cells in a time-and dose-dependent manner. Preincubation of human cells in vitro with IL-12 did not inhibit tumor cell-induced angiogenesis, suggesting that the antiangiogenic capacity of IL-12 is restricted to in vivo conditions. Treatment of the mice with rat antibody against murine interferon-gamma (IFN-gamma) resulted in counteracting the antiangiogenic effect of murine IL-12. Furthermore, human IFN-gamma inhibited the angiogenic activity of human tumor cell lines. This indicates that IFN-gamma is a mediator of the antiangiogenic effect of IL-12. The results show that the mechanism of antitumor action of IL-12 may depend not only on the immunostimulatory activity of this cytokine but also on its effect on tumor cell-induced angiogenesis. IL-12 should be considered as a potential candidate for the treatment of angiogenesis-dependent malignancies.

Vitamin D3 is a potent inhibitor of tumor cell-induced angiogenesis

Vitamin D3 derivative 1,25-dihydroxyvitamin D3 (1,25[OH]2D3) exerts various biological effects in cells that possess vitamin D3 receptor (VDR), including enhancement of cell differentiation and inhibition of cell proliferation. These activities of 1,25(OH)2D3 might be responsible for its anti-neoplastic effects, as shown in various experimental systems. The aim of this study was to compare the anti-angiogenic activity of 1,25(OH)2D3, retinoids, and interleukin-12 (IL-12) in an experimental tumor cell-induced angiogenesis assay in mice. Tumor cell-induced angiogenesis assay was performed in x-ray immunosuppressed BALB/c mice by intradermal injections of human tumor cell lines of different origin. The injections resulted within 3 d in a local formation of new blood vessels, and the intensity of angiogenesis correlated with the number of injected cells. Systemic treatment of the mouse recipients with 1,25(OH)2D3 significantly decreased angiogenesis, comparable to the effect of retinoids (all-trans retinoic acid [RA], 9-cis RA and 13-cis RA) and of IL-12. In vitro preincubation of the cells with all compounds (except IL-12) led to the inhibition of their angiogenic capability in vivo. Moreover, combination of 1,25(OH)2D3 and retinoids resulted in a synergistic inhibition of angiogenesis. The results strongly suggest that anti-angiogenic compounds with relatively low toxicity (e.g., 1,25(OH)2D3, retinoids, and IL-12) and their combinations could be beneficial in the treatment of some angiogenesis-associated malignancies.

Retinoids, interferon alpha, 1,25-dihydroxyvitamin D3 and their combination inhibit angiogenesis induced by non-HPV-harboring tumor cell lines. RAR alpha mediates the antiangiogenic effect of retinoids

Retinoids combined with interferon alpha-2a (IFN alpha) or 1,25-dihydroxyvitamin D3 [1,25(OH)2D3] have shown marked synergistic inhibitory effects on angiogenesis induced by tumor cell lines harboring DNA of oncogenic human papillomaviruses (HPV) type 16 or 18. This report demonstrates comparable effects of these compounds on angiogenesis induced by non-HPV-bearing transformed cell lines, including breast carcinoma (T47D) and vulval carcinoma (A431) cell lines. Systemic treatment of mice with all-trans retinoic acid, 13-cis retinoic acid, 9-cis retinoic acid, IFN alpha or 1,25(OH)2D3 significantly decreased tumor cell-induced angiogenesis (TIA). In vitro pretreatment of T47D and A431 cells with these compounds also led to inhibition of their angiogenic capability when tested in the TIA assay. The inhibitory effects of retinoids could be counteracted by a selective antagonist of the nuclear retinoic acid receptor RAR alpha, suggesting a RAR alpha mediated mechanism of angiogenesis inhibition. The antiangiogenic effect of retinoids could be significantly enhanced by combination with IFN alpha or 1,25(OH)2D3. The results provide a further basis for the use of combinations of retinoids with IFN alpha or 1,25(OH)2D3 in the treatment of angiogenesis-dependent malignancies.

Synergistic effect of retinoids and interferon alpha on tumor-induced angiogenesis: anti-angiogenic effect on HPV-harboring tumor-cell lines

Various retinoids and interferons exert anti-tumor effects both in experimental studies and in clinical trials. Recent reports indicate that they have a synergistic antineoplastic activity. Our study aimed to determine whether these synergistic anti-tumor effects are related to inhibition of tumor-cell-induced angiogenesis. A further aim was to compare the anti-angiogenic activity of various retinoids including 9-cis retinoic acid, a ligand for nuclear retinoic acid receptor RXR, given alone and in combination with interferon alpha-2a (IFN alpha-2a). An in vivo experimental model of cutaneous angiogenesis in the mouse was used. Angiogenesis was induced by intradermal injection of HPV16- or HPV18 DNA-harboring tumor-cell lines. All-trans retinoic acid (all-trans RA), 13-cis retinoic acid (13-cis RA) and 9-cis retinoic acid (9-cis RA) as well as IFN alpha-2a applied to mice intraperitoneally for 5 consecutive days before induction of angiogenesis resulted in significant inhibition of angiogenesis. Combination of retinoids with IFN alpha-2a led to a synergistic inhibition of angiogenesis, as compared to the effects of the drugs given alone. Similar results were obtained when tumor cells were preincubated in vitro with the compounds, before injection into untreated mice. Our findings on synergistic anti-angiogenic effects of retinoids and IFN alpha-2a could explain, at least partially, the anti-tumor efficacy of combined therapy with these agents, and provide support for the role of angiogenesis in tumor growth.

Inhibition of tumor cell-induced angiogenesis by retinoids, 1,25-dihydroxyvitamin D3 and their combination

Tumor-induced angiogenesis (TIA), i.e., the ability of transformed cells to stimulate new blood vessel formation is an important factor contributing to tumor growth and invasiveness. The antiangiogenic effect of the retinoids, all-trans retinoic acid, 13-cis retinoic and 9-cis retinoic acid, of 1,25-dihydroxyvitamin D3, and of their combinations were studied using an experimental system in vivo. TIA was induced in immunosuppressed mice by intradermal injection of the two human transformed keratinocyte lines, Skv-e2, harboring DNA of human papillomavirus (HPV) type 16, and HeLa, harboring HPV18 DNA. The three retinoids and 1,25-dihydroxyvitamin D3, when administered systemically to mice, before the angiogenesis assay significantly decreased TIA. Their combination led to a synergistic inhibition of TIA. These results provide the basis for the use of combination of retinoids and 1,25-dihydroxyvitamin D3 in treatment of neoplastic diseases.

Antitumor action of retinoids: inhibition of tumor cell line-induced angiogenesis and prevention of tumors in mice

Acitretin was shown to inhibit angiogenic response to the tumorigenic SKV cell line bearing HPV16 genome and to sarcoma L-1 cell line, both in vitro and in vivo systems. The lowered angiogenic response to tumor cells was independent of duration and timing of the application of acitretin to animals. Acitretin, but not etretinate, was also found to be effective in the prevention of sarcoma tumors in mice.

Acitretin decreases tumor cell-induced angiogenesis

The effects of acitretin and etretinate on angiogenesis induced in Balb/c mice by intradermal injection of keratinocyte tumor cell lines were evaluated. It was shown that both retinoids are capable of inhibiting angiogenesis evoked by a human epidermoid carcinoma cell line (A431). Acitretin, but not etretinate, inhibited also angiogenesis induced by the spontaneously transformed murine keratinocyte cell line Pam 212 and by the established tumorigenic SKv cell line harboring the HPV16 genome. We suggest that inhibition of blood vessel formation may be one of the mechanisms responsible for the anticancerogenic effect of retinoids.

[Studies of the role of cellular immunity and angiogenetic changes in the pathogenesis of circumscribed scleroderma]

The studies were performed in 48 patients with morphea and included evaluation of 1) antinuclear antibodies 2) lymphocyte induced angiogenesis 3) natural killer (NK) cell activity and 4) T cell subpopulations in peripheral blood. The presence of antinuclear antibodies was found in 44.4% (8/18) patients with scleroderma linearis and in 21% (4/19) patients with morphea disseminata. Lymphocyte induced angiogenesis was increased in 41.5% (17/41) morphea patients, mainly in cases with pronounced vascular changes. The E rosette forming test showed a decreased percentage of active rosette forming cells (ARFC) and total rosette forming cells (TRFC) in peripheral blood and the NK cell activity was lowered in patients with morphea. These results obtained in patients with morphea show some similarities and differences in comparison to cellular immunity disturbances in patients with systemic scleroderma.

Enhanced angiogenic capability of monocyte-enriched mononuclear cell suspensions from patients with systemic scleroderma

Different subsets of peripheral blood mononuclear cells (MNC) from 15 patients with systemic scleroderma were tested for their ability to evoke angiogenesis in a xenogenic system. The angiogenic capability of total MNC from patients with systemic scleroderma was lower than that of normal human cells, irrespective of the form of the disease. However, the capability of a monocyte-enriched subset of MNC from patients with scleroderma was found to be increased, as compared with their total MNC and with that of the corresponding subset from healthy individuals. This might be due to the activation of monocytes in the disease.

Modulatory effect of sera from scleroderma patients on lymphocyte-induced angiogenesis

Sera from 22 patients with progressive systemic sclerosis were tested for the ability to modify the angiogenic capability of normal human mononuclear cells. The sera from patients with acrosclerosis, including the abortive form (CREST syndrome: calcinosis, Raynaud's phenomenon, esophageal dysmotility, sclerodactyly, telangiectasias), markedly enhanced this capability compared with sera from both healthy donors and patients with severe acrosclerosis and diffuse scleroderma. The enhancing effect of sera from patients with acrosclerosis decreased and/or disappeared in cases where the patient's acrosclerosis was chronic and severe. Thus, this test may be of diagnostic value in distinguishing various subgroups of systemic sclerosis.