P-wave beat-to-beat analysis to predict atrial fibrillation recurrence after catheter ablation

Introduction

Identification of patients prone to atrial fibrillation (AF) relapse after catheter ablation is essential for better patient selection and risk stratification.

Purpose

The current prospective cohort study aims to validate a novel P-wave index based on beat-to-beat (B2B) P-wave morphological and wavelet analysis designed to detect patients with low burden AF, as a predictor of AF recurrence within a year after successful catheter ablation.

Methods

12-lead ECG and 10-minute vectorcardiogram (VCG) recordings were obtained from 138 consecutive patients scheduled for AF ablation. Pre-ablation B2B P-wave index, along with standard P-wave indices, clinical scores and patients history and physical examination parameters were evaluated as AF recurrence predictors.

Results

Univariate analysis revealed that patients with higher B2B P-wave index had a two-fold risk for AF recurrence (HR: 2.35, 95% CI: 1.24–4.44, p: 0.010). Prolonged P-wave, interatrial block, early AF recurrence, female gender, heart failure history, previous stroke, and CHA2DS2-VASc score ≥2 were also found to be related to higher recurrence rate. Multivariate analysis of predictors that can be assessed before ablation revealed that B2B P-wave index, along with heart failure history and history of previous stroke or transient ischemic attack are independent predicting factors of AF relapse.

Conclusion

B2B P-wave morphology and wavelet analysis, is a promising, non-invasive technique, able to identify patients prone to AF recurrence after pulmonary veins ablation. Further studies are needed to assess the predictive value of B2B index with greater accuracy and evaluate a possible relationship with atrial substrate analysis.

Funding Acknowledgement

Type of funding sources: Public Institution(s). Main funding source(s): Hellenic Society of Cardiology

Hot balloon versus cryoballoon ablation in patients with atrial fibrillation: a systematic review and meta-analysis

Funding Acknowledgements

Type of funding sources: None.

Background

Atrial fibrillation (AF) incidence is expected to increase more than 60% in the following 30 years. Catheter ablation is the treatment of choice for medically intractable AF with arrhythmia recurrence remaining an unsolved issue.

Purpose

We systematically reviewed existing literature to compare the efficacy of hot balloon (HBA) versus cryoballoon ablation (CBA).

Methods

PubMed, Scopus, ClinicalTrials.gov, medRxiv and Cochrane Library (according to PRISMA guidelines) were scrutinized for relevant articles up to 2 December 2021. Eligible studies had to compare clinical outcomes (arrhythmia recurrence rates or/and procedural data or/and safety outcomes) between patients undergoing HBA and CBA for AF. Quality assessment of studies was conducted via the Newcastle-Ottawa Scale (high quality≥ 7, moderate 4-6, poor <4). Statistical pooling was performed according to a random-effect model with generic inverse-variance weighting of odds ratios and mean differences computing risk estimates with 95% confidence intervals. The presence of heterogeneity among studies was evaluated under the Cochran Q chi-square test. I² values of 25%, 50% and 75% have been assigned adjectives of low, moderate, and high heterogeneity. Publication biases were assessed by visual inspection of funnel plots.

Results

PRISMA study search and individual study characteristics are presented in Figure 1. Literature search identified 131 studies, 5 of which (evaluating 513 patients) met inclusion criteria. Patients undergoing HBA demonstrated similar long term recurrence rate as compared to CBA treated controls (OR: 0.68; 95% CI: 0.38-1.22; p-value: 0.19; I2: 0%). Procedural aspects, such as touch-up radiofrequency ablation (per pulmonary vein), procedure time (min) and fluoroscopic time (min) did not differ among treatment arms (OR: 1.79; 95% CI: 0.84-3.83; p-value: 0.13, I2: 80%, MD: 9.69; 95% CI: -2.78-22.16; p-value: 0.13, I2: 63%, and OR: 1.03; 95% CI: -9.50-7.44; p-value: 0.81, I2: 87%, respectively). Regarding safety outcomes (Figure 1), the small number of the reported events precluded us from analyzing these data. Yet, tamponade and phrenic nerve injury were infrequent in both modalities; pulmonary vein stenosis of at least moderate severity (>50% luminal narrowing) was reported in 18 instances in the HBA arm as compared to zero events in the CBA arm. Of note, all events were asymptomatic. Quality assessment scores are shown in Figure 1. Four studies were of high quality and one study was of moderate quality. Funnel-plot distributions of the pre-specified outcomes indicated absence of publication bias for all outcomes. High statistical heterogeneity and the small number of patients included are the main limitations of this study.

Conclusion

Hotballoon ablation is a promising therapeutic option for patients suffering from AF, featuring comparable efficacy and procedural outcomes with cryoablation. Safety outcomes, especially PV stenosis, mandate further evaluation.

Subclavian versus axillary vein puncture for implantation of cardiac electronic devices. A meta-analysis

Background

Implantation of CIED has become a daily practice for patients with rhythm disturbances, those with an indication for primary or secondary sudden cardiac death prevention as well as for patients with heart failure and marked ventricular dyssynchrony. Most of the complications observed following implantation seem to be procedure-related. The latter has led many physicians to replace the classic subclavian approach with alternative techniques such as cephalic vein cut-down and axillary vein puncture (AVP). Recent data support that these techniques may be associated with similar success rates and lower adverse events.

Purpose

This meta-analysis was performed to compare axillary to subclavian vein puncture (SVP) for implantation of cardiac implantable electronic devices (CIED), in terms of safety and efficacy.

Methods

We searched MedLine, via PubMed, for studies comparing subclavian to axillary vein approach in terms of safety and efficacy. Safety endpoints were considered the incidence of pneumothorax, device related infections and major bleeding events. Efficacy and feasibility were assessed by the incidence of lead failure (lead dislodgement, lead fracture or insulation defects) and the number of successfully cannulated veins, respectively. Studies were judged as eligible if they reported at least one of the predefined outcomes. Effect size was calculated using the risk difference along with the corresponding 95% confidence interval (CI). A random- effects DerSimonian-Laird model was adopted.

Results

Seven studies fulfilled the inclusion criteria and were included in the final analysis, resulting in 3642 patients (59.1% males) with a pooled mean (SD) age of 66.1 (12.7) years. Axillary vein puncture (AVP) was performed in 45.8% of them. All, but one study, used fluoroscopic guidance (with or without venography) for axillary vein cannulation. The CIED most commonly implanted was a permanent pacemaker (73%). Both techniques resulted in similar percentages of successful cannulations (1066/1099 for AVP and 906/931 for SVP, RD: 0; 95% CI: −0.01–0.01, I2: 0%, Figure 1A). There was a significantly higher risk for pneumothorax with the subclavian approach (RD: 0.02; 95% CI: 0.01–0.03, I2: 49.31%, Figure 2A). No significant differences were observed regarding the incidence of bleeding and infections (Figure 2B, 2C). SVP was also associated with a significantly increased risk for lead failure (RD: 0.01; 95% CI: 0.00–0.03, I2: 48.47%, Figure 1B).

Conclusions

AVP seems to be a feasible approach for implantation of CIED. Moreover, it seems to be both a more safe and effective choice compared to SVP, as it is associated with reduced risk for pneumothorax and lead failure. More data especially comparing AVP to cephalic cut-down are needed to safely guide the daily practice.

Funding Acknowledgement

Type of funding sources: None. Figure 1Figure 2

Is there an antiarrhythmic benefit from switching to sacubitril/valsartan therapy? A systematic review and meta-analysis

Background

Sacubitril/valsartan through reverse structural remodeling and neurohormonal inhibition could play an antiarrhythmic role.

Purpose

This systematic review and meta-analysis was performed to explore the arrhythmiologic effects of switching patients with heart failure with reduced ejection fraction (HFrEF) from angiotensin converting enzyme inhibitors (ACEi) or angiotensin receptor blockers (ARBs) to sacubitril/valsartan.

Methods

We searched major databases for studies comparing device-detected, incident atrial and ventricular arrhythmias in patients with HFrEF while on ACEi/ARBs versus while on sacubitril/valsartan. For pooling the primary outcome of interest, we calculated the risk difference (RD) with the corresponding 95% confidence interval (CI) in the probability of experiencing each arrhythmic event while on ACEi/ARBs and while on sacubitril/valsartan. A random effects (DerSimonian-Laird) model was adopted.

Results

We analyzed 4 eligible studies, resulting in 497 patients with a pooled mean age of 67.8±10.36. 64% had ischemic cardiomyopathy while 98% had either an implantable cardioverter defribrillator or a cardiac resynchronization therapy device. Main comorbidities were hypertension (68.7%) and dyslipidemia (59.6%). Almost all (96.3%) patients were treated with b-blockers and 23.7% were also receiving anti-arrhythmic drugs, mainly amiodarone. After switching to sacubitril/valsartan there was a trend towards reduced risk for sustained ventricular tachycardia/fibrillation and non-sustained ventricular tachycardias (RD: −0.04, 95% CI: −0.09–0.02, I2: 65.7% and −0.06, 95% CI: −0.19–0.07, I2: 85%; respectively). Meta-regression analysis showed that patients with ischemic cardiomyopathy experience greater benefit. Incident paroxysmal atrial fibrillation/tachycardia was significantly reduced (RD: −0.09 95% CI: −0.14 to −0.03, I2: 0%), while favorable effects were noticed for the risk of appropriate shock delivery and inadequate biventricular pacing (RD: −0.06, 95% CI: −0.09 to −0.03, I2: 0% and −0.06, 95% CI: −0.11 to 0.00, I2: 35.55%, respectively). All results seem to suffer from publication bias.

Conclusion

Limited data support that switching to sacubitril/valsartan seems to be associated with reduced risk for both ventricular and atrial arrhythmias. More studies are needed to clarify the potential anti-arrhythmic role of this drug. Whether patients with frequent arrhythmias or at high arrhythmic risk may benefit from early switch is a matter of further investigation.

Funding Acknowledgement

Type of funding sources: None. Figure 1Figure 2

L10-FeNi films on Au-Cu-Ni buffer-layer: a high-throughput combinatorial study

The fct L10-FeNi alloy is a promising candidate for the development of high performance critical-elements-free magnetic materials. Among the different materials, the Au-Cu-Ni alloy has resulted very promising; however, a detailed investigation of the effect of the buffer-layer composition on the formation of the hard FeNi phase is still missing. To accelerate the search of the best Au-Cu-Ni composition, a combinatorial approach based on High-Throughput (HT) experimental methods has been exploited in this paper. HT magnetic characterization methods revealed the presence of a hard magnetic phase with an out-of-plane easy-axis, whose coercivity increases from 0.49 kOe up to 1.30 kOe as the Au content of the Cu-Au-Ni buffer-layer decreases. Similarly, the out-of-plane magneto-crystalline anisotropy energy density increases from 0.12 to 0.35 MJ/m3. This anisotropy is attributed to the partial formation of the L10 FeNi phase induced by the buffer-layer. In the range of compositions we investigated, the buffer-layer structure does not change significantly and the modulation of the magnetic properties with the Au content in the combinatorial layer is mainly related to the different nature and extent of interlayer diffusion processes, which have a great impact on the formation and order degree of the L10 FeNi phase.

The metabolic impact of extracellular nitrite on aerobic metabolism of Paracoccus denitrificans

Nitrite, in equilibrium with free nitrous acid (FNA), can inhibit both aerobic and anaerobic growth of microbial communities through bactericidal activities that have considerable potential for control of microbial growth in a range of water systems. There has been much focus on the effect of nitrite/FNA on anaerobic metabolism and so, to enhance understanding of the metabolic impact of nitrite/FNA on aerobic metabolism, a study was undertaken with a model denitrifying bacterium Paracoccus denitrificans PD1222. Extracellular nitrite inhibits aerobic growth of P. denitrificans in a pH-dependent manner that is likely to be a result of both nitrite and free nitrous acid (pK_a = 3.25) and subsequent reactive nitrogen oxides generated from the intracellular passage of FNA into P. denitrificans. Increased expression of a gene encoding a flavohemoglobin protein (Fhp) (Pden_1689) was observed in response to extracellular nitrite. Construction and analysis of a deletion mutant established Fhp to be involved in endowing nitrite/FNA resistance at high extracellular nitrite concentrations. Global transcriptional analysis confirmed nitrite-dependent expression of fhp and indicated that P. denitrificans expressed a number of stress response systems associated with protein, DNA and lipid repair. It is therefore suggested that nitrite causes a pH-dependent stress response that is due to the production of associated reactive nitrogen species, such as nitric oxide from the internalisation of FNA.

Impaired phagocytosis among patients infected by the human immunodeficiency virus: implication for a role of highly active anti-retroviral therapy

In patients with human immunodeficiency virus (HIV) infection, neutrophil and monocyte functions, including phagocytosis, are impaired. The purpose of this study was to investigate changes of phagocytic function and respiratory burst occurring over the course of patients infected by the HIV-1 virus. Treatment-naive patients (group B), patients receiving highly active anti-retroviral treatment (HAART) (group C) and patients in which HAART has failed (group D) were studied and compared with healthy volunteers (group A). Phagocytosis and oxidative burst were evaluated using commercially available kits. Results clearly denote a significant decrease of the phagocytic function of both cell types of groups B and C compared with group A. Among group C patients, those in the upper quartile of CD4 increase had higher oxidative burst compared with patients of the other quartiles. In addition, comparisons clearly showed a lower degree of phagocytic function and of oxidative burst of both monocytes and neutrophils of group D compared with group B. Finally, it was found that monocyte and neutrophil function was correlated inversely to the change in viral load, i.e. the greater the decrease of viral load, the better the phagocytic and oxidative activity. Innate immunity defects appear to be present in HIV-positive patients, regarding phagocytic activity and oxidative burst of monocytes and neutrophils. These defects are greatly influenced by the level of treatment efficacy, with emphasis on CD4 cell counts and viral load.

Short-term fluctuations of plasma NT-proBNP levels in patients with new-onset atrial fibrillation: a way to assess time of onset?

OBJECTIVE

The objective of this study was to characterise short-term kinetics of plasma amino-terminal pro-B natriuretic peptide (NT-proBNP) levels in patients with new-onset atrial fibrillation (AF) without heart failure.

DESIGN

Prospective cohort study.

SETTING

Emergency departments and inpatient services of three large community hospitals.

PATIENTS

31 consecutive patients with new-onset atrial fibrillation (<24 h before presentation) persisting at least 48 h, without evidence of heart failure.

MAIN OUTCOME MEASURES

Plasma NT-proBNP levels were obtained at presentation and then 6, 12, 18, and 24 h after presentation. A final sample was obtained 48 h after onset of AF.

RESULTS

Mean plasma NT-proBNP levels and 95% CIs (pg/ml) during the 48-h period following onset of AF were: 0-6 h: 636 (395 to 928), 6-12 h: 1364 (951 to 1778), 12-18 h: 1747 (1412 to 2083), 18-24 h: 1901 (1549 to 2253), 24-36 h: 1744 (1423 to 2066) and 36-48 h: 1101 (829 to 1373). Mean time to peak NT-proBNP levels was 16.7 (0.7) h; 29 patients reached their peak levels within 24 h. The mean peak NT-proBNP level was significantly higher than those obtained at 0-6 h and at 36-48 h after onset of AF (p<0.001 for both). There was no correlation between ventricular rate and plasma NT-proBNP levels during any time period after onset of AF.

CONCLUSION

In patients with new-onset AF but no clinical or radiographic evidence of heart failure, plasma NT-proBNP levels rise progressively to a peak during the first 24 h and then rapidly fall. This pattern may serve as an aid to assess the time from AF onset.

Risk assessment of the fatality due to explosion in land mass transport infrastructure by fast transient dynamic analysis

Terrorist attacks in New York have shocked the world community showing clearly the vulnerability of air transport in such events. However, the terrorist attacks in Madrid and London showed that land mass transport infrastructure is equally vulnerable in case of similar attacks. The fact that there has not been substantial investment in the domain of risk analysis and evaluation of the possible effects due to such events in land mass transportation infrastructure leaves large room for new developments that could eventually fill this gap. In the present work using the finite element code EUROPLEXUS there has been a large effort to perform a complete study of the land mass infrastructure in case of explosion events. This study includes a train station, a metro station and a metro carriage providing thus valuable simulation data for a variety of different situations. For the analysis of these structures it has been necessary to apply a laser scanning method for the acquisition of geometrical data, to improve the simulation capabilities of EUROPLEXUS by adding failure capabilities for specific finite elements, to implement new material models (e.g. glass), and to add new modules that achieve data post-processing for the calculation of fatal and non-fatal injuries risk. The aforementioned improvements are explained in the present work with emphasis in the newly developed risk analysis features of EUROPLEXUS.

Corrleation of health-related quality of life (HRQL) of cancer patients and the mental component parameters of their family members

e20619

Background: It is widely experienced that health-related quality of life (HRQL) is greatly influenced in the family members of cancer patients. The aim of this study was to find the correlation of the HRQL parameters in cancer patients with the main mental component parameters of patients’ relatives. Methods: 122 cancer patients undergoing chemotherapy in our department (49 men and 73 women) of mean age 56.6 ±15.4 1SD and their 122 relatives that accompanied them (45 men and 77 women) of mean age 48.3 ±14.5 completed the validated SF-36 health survey by personal interview. The SF-36 health survey summarizes the functional health status and general health into eight scales with higher scores (0–100 range) reflecting better-perceived health. In this study, physical functioning (PF), role physical (RP), bodily pain (BP), general health perception (GH), vitality (VT), social functioning (SF), role emotional (RE), and mental health (MH) of the patients were correlated with the SF, RE, MH of their family members using the Spearman's test. Data analysis was performed with SPSS version 13.0 and correlations were considered statistically significant when p<0.05. Results: Table 1 summarizes the results of our study. Social Functioning and Mental Health of family members are highly correlated with the HRQL parameters of cancer patients. The RE does not seem to be affected. Conclusions: HRQL of cancer patients undergoing chemotherapy is highly correlated with the SF and the MH of their relatives. This observation highlights the need to develop more oriented supportive programs for both the patients and their family memebers. Abbreviations: PF = Physical Functioning, RP = Role Physical, BP = Bodily Pain, GH = General Health, VT = Vitality, SF = Social Functioning, RE = Role Emotional, MH = Mental Health; NS=Not Significant. * = 0.05. ** = 0.01.

[Table: see text]

No significant financial relationships to disclose.

Comparing health-related quality of life (HRQL) of cancer patients undergoing chemotherapy with family members in a tertiary hospital

e20535

Background: In Greece there is limited information concerning the HRQL of cancer patients undergoing chemotherapy. The aim of this study was to estimate and compare the HRQL of cancer patients and their relatives during the period of chemotherapy and to investigate potential differences in HRQL. Methods: 122 family members (45 men and 77 women) of mean age 48.3 ±14.5 and 122 cancer patients undergoing chemotherapy (49 men and 73 women) of mean age 56.6 ±15.4 1SD completed the SF-36 health survey by personal interview. The SF-36 health survey was used to evaluate and compare HRQL which contains eight scales measuring physical functioning (PF), role physical (RP), bodily pain (BP), general health perception (GH), vitality (VT), social functioning (SF), role emotional (RE), and mental health (MH), with higher scores (0–100 range) reflecting better-perceived health. Two component summary scores capture the overall physical and mental health (Physical Component Summary or PCS and Mental Component Summary or MCS). Data analysis was performed with SPSS version 13.0 while statistical analysis was performed with Wilcoxon signed ranks test. Results: The table below summarizes the results of our study. Conclusions: Although the physical health was significantly higher in the family members as it was expected for a healthy population, the mental health and especially MCS was significantly lower from the cancer patients undergoing chemotherapy. It seems that medical condition of the patients affects severely the mental HRQL of family members. Supportive psychological programs for both the patients and the family members seem mandatory.

[Table: see text]

No significant financial relationships to disclose.

DIANA-microT web server: elucidating microRNA functions through target prediction

Computational microRNA (miRNA) target prediction is one of the key means for deciphering the role of miRNAs in development and disease. Here, we present the DIANA-microT web server as the user interface to the DIANA-microT 3.0 miRNA target prediction algorithm. The web server provides extensive information for predicted miRNA:target gene interactions with a user-friendly interface, providing extensive connectivity to online biological resources. Target gene and miRNA functions may be elucidated through automated bibliographic searches and functional information is accessible through Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways. The web server offers links to nomenclature, sequence and protein databases, and users are facilitated by being able to search for targeted genes using different nomenclatures or functional features, such as the genes possible involvement in biological pathways. The target prediction algorithm supports parameters calculated individually for each miRNA:target gene interaction and provides a signal-to-noise ratio and a precision score that helps in the evaluation of the significance of the predicted results. Using a set of miRNA targets recently identified through the pSILAC method, the performance of several computational target prediction programs was assessed. DIANA-microT 3.0 achieved there with 66% the highest ratio of correctly predicted targets over all predicted targets. The DIANA-microT web server is freely available at www.microrna.gr/microT.

CLimate Impacts on Myocardial infarction deaths in the Athens TErritory: the CLIMATE study

OBJECTIVE

To evaluate the impact of meteorological variables on daily and monthly deaths caused by acute myocardial infarction (AMI).

METHODS

All death certificate data from the Athens territory were analysed for AMI deaths in 2001. Daily atmospheric temperature, pressure and relative humidity data were obtained from the National Meteorological Society for Athens for the same year.

RESULTS

The total annual number of deaths caused by AMI was 3126 (1953 men) from a population of 2,664,776 (0.117%). Seasonal variation in deaths was significant, with the average daily AMI deaths in winter being 31.8% higher than in summer (9.89 v 7.35, p < 0.001). Monthly variation was more pronounced for older people (mean daily AMI deaths of people older than 70 years was 3.53 in June and 7.03 in December; p < 0.001) and of only marginal significance for younger people. The best predictor of daily AMI deaths was the average temperature of the previous seven days; the relation between daily AMI deaths and seven-day average temperature (R(2) = 0.109, p < 0.001) was U-shaped. Considering monthly AMI death rates, only mean monthly humidity was independently associated with total deaths from AMI (R(2) = 0.541, p = 0.004).

CONCLUSION

Ambient temperature is an important predictor of AMI mortality even in the mild climate of a Mediterranean city like Athens, its effects being predominantly evident in the elderly. Mean monthly humidity is another meteorological factor that appears to affect monthly numbers of AMI deaths. These findings may be useful for healthcare and civil protection planning.

The prevalence of hepatitis C and hepatitis G virus infection in patients with B cell non-Hodgkin lymphomas in Greece: a Hellenic Cooperative Oncology Group Study

Our aim was to investigate the association between chronic hepatitis C virus (HCV) infection and B cell non-Hodgkin lymphoma (NHL) in the Greek population. We studied 120 patients (70 men and 50 women, mean age 59 years) diagnosed with NHL. One hundred and eight had B cell NHL (90%) and 12 had T cell NHL (10%). The presence of anti-HCV antibodies in patients and controls was investigated using the monoclonal enzymatic immunoassay (MEIA) method. The detection of HCV RNA and hepatitis G virus (HGV) RNA in patients with B cell NHL and anti-HCV-positive controls was performed using an RT-PCR technique. Anti-HCV antibodies were present in only 2 of the 108 patients with B cell NHL (1.9%), while the prevalence of HCV infection in the healthy population was 0.6%, and in patients with various solid tumors treated with chemotherapy, it was 0.99%. Ten of the 108 B cell NHL patients (9.26%) were diagnosed as HGV RNA positive, while the prevalence of HGV infection in 285 Greek blood donors was 0.7%. Our findings do not confirm a strong association between HCV infection and B cell NHL for Greek patients. The increased prevalence of HGV infection detected in patients with NHL could imply the potential participation of HGV in the pathogenesis of NHL.

Bone mineral density of vertebrae, proximal femur and os calcis in normal Greek subjects as assessed by dual-energy X-ray absorptiometry: comparison with other populations

Dual energy X-ray absorptiometry (DXA) is an established method for the detection of even small changes in bone mineral density (BMD). It thus allows the earliest possible diagnosis of osteopenia, with consequent prompt estimation of fracture risk. However, for proper evaluation of densitometry results it is essential that a comparison with reference BMD values of normal age- and sex-matched persons from the same population be performed. For this purpose we determined bone density of the L2-L4 vertebrae, the L3 vertebra in the lateral projection, the proximal femur and the os calcis in a cross-sectional study of 168 men and 244 women from the Greek population. The age range of the subjects was 20-80 years. Peak bone mass for both sexes was attained in the 30-35 year age group for the vertebrae and in the 25-30 year age group for the proximal femur and os calcis. Mean annual vertebral bone loss calculated on cross-sectional data ranged from 0.1% to 0.22% for women < 50 years and from 1.3% to 1.6% for those > 50 years, whereas in men the range was from 0.36% to 0.64% for the whole age spectrum. Regarding femoral neck, the values wer 0.3% (women < 50 years), 1.2-1.5% (> 50 years) and 0.6-0.8% for men. Total bone loss between ages 20 and 70 was 29.5% for the vertebrae and 32% for the femoral neck in women, whereas the values for men were 19.5% and 29% respectively. A positive correlation was observed between bone density, body weight and body height in both sexes. Body mass index correlated significantly with density only in postmenopausal women. Compared with North American, Finnish and German populations, Greek men presented with lower BMD values in the decades above 40 years. Greek women exhibited lower vertebral BMD values than those from the USA. Germany and Japan (50-60 age group), whereas they did not differ from those of Finnish women. However, femoral neck BMD in Greek women was higher than in Japanese women in all age groups.

Tuberculous esophagitis. Report of a case and review of modern approaches to diagnosis and treatment

We describe a patient with tuberculous esophagitis who was referred to us with low-grade fever, but no esophageal symptoms. The diagnosis was established in biopsies obtained from a deep midesophageal ulcer seen on endoscopy. Investigation of the patient failed to identify any extra-esophageal tuberculous foci, but a computed tomography scan revealed mediastinal lymphadenopathy without lung involvement. Primary infection of the esophagus by tuberculosis is questioned, and widespread use of computed tomography may show it to be a fiction.

Dopamine binding to the alpha receptor in pregnant rabbit myometrium

This study evaluated in vitro binding of dopamine ligands to myometrial alpha adrenoceptors. With cell membranes from pregnant rabbits, receptor radioligand binding studies utilizing [3H] dihydroergocryptine +/- dopamine demonstrated receptor affinity (KD) = 0.75 +/- 0.10 nM (+/- SEM) and density (Bmax) = 533.2 +/- 45.2 fM/mg protein. Similar studies utilizing phentolamine or apomorphine gave essentially identical results. Competition binding studies demonstrated steriospecific butaclamol binding, along with significant binding of haloperidol, spiperone, apomorphine, and bromoergocryptine. These observations provide a mechanism for the observed uterotonic effects of dopamine.

Prostaglandin E and F2 alpha receptors in human myometrium during the menstrual cycle and in pregnancy and labor

The binding of prostaglandins E1 and F2 alpha has been studied in the human myometrium and cervix during the menstrual cycle and in the myometrium of pregnant patients at term before and during labor. Tritium-labeled prostaglandin E1 and F2 alpha binding was saturable and reversible. Scatchard analysis of tritium-labeled prostaglandin E1 binding was linear, which suggests a single class of high-affinity binding sites with an estimated apparent equilibrium dissociation constant of 2.5 to 5.4 nmol/L and inhibitor affinities of 0.9, 273, 273, and 217 nmol/L for prostaglandins E2, A1, B1, and F2 alpha, respectively. Scatchard analysis of tritium-labeled prostaglandin F2 alpha, binding was also linear, but the affinity of these binding sites was much lower, with an average dissociation constant of 50 nmol/L and inhibitor affinities of 1.6, 2.2, and 11.2 nmol/L for prostaglandins E1, E2, and A1, respectively. In nonpregnant patients, the concentrations and affinities of tritium-labeled prostaglandin E1 binding sites were similar in the myometrium during the proliferative and secretory phases of the menstrual cycle, but the concentration of these sites was much lower in the cervix. The concentration of the tritium-labeled prostaglandin E1 binding sites was significantly lower in the myometrium of pregnant patients at term than in the myometrium of nonpregnant patients. The concentrations and affinities of tritium-labeled prostaglandin E1 binding sites were not significantly different in the upper and lower myometrium of pregnant patients at term or in the myometrium of such patients before and during labor. The concentrations of the tritium-labeled prostaglandin F2 alpha binding sites during the menstrual cycle and in pregnancy at term were similar to those of tritium-labeled prostaglandin E1 binding sites. In addition to confirming the presence of specific prostaglandin E and F2 alpha binding sites in the myometrium, these data also suggest: that specific prostaglandin E binding sites are present in the cervix and that the concentrations and affinities of prostaglandin E binding sites do not change during the menstrual cycle and are similar before and during labor in pregnant patients at term.

Immune abnormalities in myelodysplastic syndromes

The immune states of 52 patients with myelodysplastic syndromes classified according to the FAB criteria were studied. Serum electrophoresis and immunoelectrophoresis, direct Coombs test, and tests for organ and non-organ specific antibodies were performed. Twenty six patients had immunoglobulin abnormalities: six (11.5%) had monoclonal gammopathy; 17 (32.6%) had polyclonal increases in serum immunoglobulin; while in three (5.8%) immunoglobulin concentrations were decreased. The distribution of immunoglobulin abnormalities among the five myelodysplastic syndrome subtypes was fairly uniform. Results of direct Coombs test were negative in all cases. Organ specific antibodies were not detected in any of the patients tested, although two patients were found positive for antinuclear antibodies. The presence of immunoglobulin abnormalities indicates an involvement of the lymphoplasmatic system in myelodysplastic syndromes.

Influence of pulmonary endothelial cells on fetal lung development

Culture medium conditioned by pulmonary endothelial cells stimulated proliferation of cultured fetal lung cells, as measured by increases in cell numbers, incorporation of tritiated thymidine into DNA, and incorporation of labeled choline into membrane phospholipids. Medium conditioned by several other cell culture preparations of fetal lung did not elicit these effects. The growth-promoting activity was found to be concentrated in fractions of 42,000 and 89,000 molecular weight (mol wt). In addition to promoting cell growth, medium conditioned by pulmonary endothelial cells also appeared to stimulate the incorporation of labeled choline into surfactant-associated phosphatidylcholine. These results suggest that pulmonary endothelial cells may produce factors that stimulate the growth and perhaps also the differentiation of fetal lung cells in culture.

Effect of dexamethasone on the synthesis of specific proteins in fetal rabbit lung in vivo and in organ culture

Lung tissue from fetal rabbits at 24 days' gestation was maintained in organ culture in defined medium. This system has been used to study the effect of dexamethasone on general protein synthesis and on the synthesis of specific proteins by fetal rabbit lung in vitro. Glucocorticoid treatment had no effect on the overall incorporation of labeled amino acids into protein. However, it increased the incorporation of [35S] methionine into 5 of the nearly 400 proteins catalogued by two-dimensional gel electrophoresis. When tissue was taken from fetuses at 20 and 22 days' gestation, it was found that the effect of dexamethasone on the incorporation of [35S] methionine into some of these five peptides was dependent on the gestational age of the animals at the time of sacrifice. When dexamethasone was administered for 2 consecutive days to pregnant rabbits beginning on gestational day 25, two-dimensional gels of [35S] methionine-labeled slices of fetal lungs revealed several glucocorticoid treatment in vitro. Following isolation of type II cells from fetal lungs after glucocorticoid administration in vivo and labeling the cells with [35S] methionine, two-dimensional gels of cell lysates exhibited several changes, some of which are identical to the changes seen in whole lung after glucocorticoid treatment in vivo or in vitro and some that appear to be unique to type II cells.

Identification of beta-adrenergic receptors in pulmonary alveolar type II cells

Specific beta-adrenergic receptors have been identified in dissociated preparations of rabbit lung cells greatly enriched for alveolar type II cells and compared with receptors in preparations of mixed lung cells and erythrocytes. Freshly isolated type II cells as well as mixed dissociated lung cells and erythrocytes from fetal (28 days gestation) and adult rabbits contained high-affinity, low-capacity binding sites for [3H]dihydroalprenolol (DHA). Binding to all preparations was stereospecific and characteristic of the beta 1-subtype of beta-adrenergic receptors. The concentrations of the receptors were similar in mixed lung cells and alveolar type II cells, indicating that beta-adrenergic receptors are present not only in type II cells but also in other lung cell types. When the contribution of erythrocytes to receptor concentration observed in type II cells was determined, it was found to be insignificant. In mixed lung cells, both the affinity and concentration of the receptors were higher in adult than fetal preparations. The affinity of the receptors was also higher in adult than fetal type II cells, although we did not find a significant age-related difference in receptor concentrations in this cell type. These results suggest that stimulation of surfactant secretion observed after exposure of lung tissue to beta-adrenergic agonists is mediated by specific beta-adrenergic receptors on alveolar type II cells.

Specific glucocorticoid binding in human uterine tissues, placenta and fetal membranes

The binding of [3H]dexamethasone to cytosol fractions of human myometrium, endometrium, decidua, chorion, amnion and placenta has been studied. All tissues examined contained high affinity, low capacity binding sites with high specificity for glucocorticoids. Maximum specific binding of [3H]dexamethasone was reached after about 10 h at 0-4 degrees C and remained stable for at least the next 12 h. Sucrose density gradient analysis showed that the binding macromolecules sedimented at 7.9 S in hypotonic solutions and at 4.35 in solutions containing 0.4 M KCl. In the presence of sodium molybdate, the sedimentation coefficients shifted both in the absence and presence of 0.4 M KCl to 8.9 and 5.7 S, respectively. The apparent equilibrium dissociation constants (Kd) of the glucocorticoid binding sites were similar in most tissues, ranging between 1 and 6 nM, with the exception of the placenta in which the binding sites showed a higher Kd (13-22 nM). In all tissues studied, the binding affinities were similar in nonpregnant and pregnant patients and in patients at different stages of pregnancy or in labor. The concentration of the binding sites in the different tissues ranged from 11 to 268 fmol/mg protein, higher concentrations being found in myometrium, placenta and amnion and lower concentrations found in endometrium, chorion and decidua. The number of binding sites was higher in the myometrium of nonpregnant than pregnant women, but was similar in the myometrium of women at term pregnancy before or during labor. In the placenta, the number of binding sites increased significantly from early pregnancy to midpregnancy, while in chorion, amnion and decidua the number of binding sites did not change during pregnancy. It is concluded that human uterine tissues, placenta and fetal membranes contain specific binding sites with properties characteristic of glucocorticoid receptors suggesting that these tissues may respond directly to glucocorticoids.

Androgen receptors in fetal rabbit lung and the effect of fetal sex on the levels of circulating hormones and pulmonary hormone receptors

High affinity (KD = 0.2 nM), low capacity (3.6-5.0 fmol/mg protein), androgen-specific binding proteins with characteristics typical of androgen receptors were identified in the lungs of rabbit fetuses between the 26 and 29th day of gestation and in the lungs of adult rabbits. While androgen receptor concentrations increased significantly from late gestation to adulthood (P less than 0.01), no sex-related differences were observed in either the binding affinities or concentrations of the receptors at any age tested. Similarly, no sex-related differences were found in the levels of progesterone, cortisol and cortisone in the fetal circulation, or in the levels of progesterone receptors, glucocorticoid receptors and beta-adrenergic receptors in the fetal lung at 26 days of gestation. It is concluded that the fetal lung interacts directly with circulating androgens via specific androgen receptors and that the suggested male disadvantage with respect to lung maturation in the perinatal period does not appear to be associated with sex-related differences in the levels of pulmonary androgen, glucocorticoid, progesterone or beta-adrenergic receptors.

Glucocorticoid metabolism in human placenta, decidua, myometrium and fetal membranes

The metabolism of cortisone (E) and cortisol (F) by human placenta, decidua, myometrium, chorion and amnion during pregnancy was studied in vitro. Early pregnancy, midpregnancy and term placentae metabolized F efficiently yielding E as the major product. The capacity of the placenta to inactivate F to E was observed as early as the 8th week of pregnancy and there was a significantly higher (P less than 0.001) net production of E in early pregnancy placenta than in term placenta. In contrast to the placenta, midpregnancy and term decidua metabolized mainly E to F with a net production of F. Term chorion demonstrated an equal degree of oxidative and reductive glucocorticoid metabolism while term amnion and myometrium had negligible metabolic activity. Thus the net production of F from E by the decidual membrane unit is due to metabolic activity in the decidua as early as the 13th week of pregnancy and not to activity in the fetal membranes.

Hormonal regulation of beta-adrenergic receptors in fetal rabbit lung in organ culture

Explants of fetal rabbit lung were established on the 25th day of gestation. These were maintained in serum-free medium for periods up to 10 days. During this time, the cultures exhibited morphological changes typical of terminal lung differentiation. Morphological evidence was also obtained for synthesis and secretion of pulmonary surfactant in these explants. beta-Adrenergic receptors were identified in these lung explants. Exposure of the explants to 10(-7)M dexamethasone on the third day of culture resulted in a significant increase in the number of beta-adrenergic receptors in the tissue without a change in receptor affinity. The effect of dexamethasone in organ culture was dose-dependent, a maximum increase in receptor number being observed within 48 hours of incubation with a hormone concentration of 1 x 10(-7)M. Exposure of the explant tissue to 1 x 10(-7)M triiodothyronine resulted in no significant increase in the concentration of beta-adrenergic receptors and no change in receptor affinity. These results suggest that glucocorticoids may potentiate the effects of beta-adrenergic agents in the fetal lung by increasing the numbers of their receptors. The effects of triiodothyronine upon the fetal lung do not appear to be mediated by this mechanism.

Species-related differences in steroid-binding specificity of glucocorticoid receptors in lung

The steroid-binding affinities and specificities of pulmonary glucocorticoid receptors have been examined in different mammalian species. The receptors of all species examined are highly specific for binding glucocorticoids, the order of binding affinity being similar to the order of their biological potency. Progesterone also binds significantly to the receptors with an affinity varying between 16% and 41% of the corresponding affinity of corticosterone in different species. The affinity of triamcinolone acetonide for the receptor is highest in the rabbit, lowest in the guinea pig, and intermediate in the rat, mouse, and man, suggesting an inverse relationship between the affinity of glucocorticoids for the receptors and the level of glucocorticoids in blood. Glucocorticoid receptors of cortisol-secreting species (man, guinea pig, rabbit) bind cortisol with a much higher affinity than corticosterone, whereas glucocorticoid receptors of corticosterone-secreting species (rat, mouse) bind corticosterone with a much higher affinity than cortisol. In addition to cortisol, other 17 alpha-hydroxylated steroids also bind receptors of cortisol-secreting species with a relatively higher affinity than receptors of corticosterone-secreting species. Thus, in a given species glucocorticoid receptors seem to bind steroids better that are normally secreted by that species than steroids that are not secreted. A change in the pattern of glucocorticoids secreted during development (e.g. the rabbit fetus secretes primarily cortisol whereas the adult rabbit secretes predominantly corticosterone) is not accompanied by a corresponding change in the binding specificity of glucocorticoid receptors.

Unoccupied and occupied estrogen receptors in myometrial cytosol and nuclei from nonpregnant and pregnant women

Exchange assays have been developed and used to measure the total concentration of estrogen receptor sites (unoccupied and occupied with endogenous hormone) in the cytosol and nuclei of human myometrium during the menstrual cycle and in pregnancy at term, before and during labor. A major fraction of the nuclear receptors appear to be unoccupied (not complexed with estrogen). These sites were detected in both crude and highly purified myometrial nuclei, indicating that they are located in the nucleus and do not represent a cytoplasmic or other cellular contaminant. The distribution of estrogen receptors between the cytosol and the nucleus varied in pregnant and nonpregnant patients. In pregnant patients, the receptor was detected only in the nucleus, while in nonpregnant patients most of the receptor was found in the cytosol. The levels of total receptor were considerably lower (5 times) in pregnancy at term than during the menstrual cycle. No significant differences in cytosol receptor levels or in unoccupied nuclear receptor levels were observed between the proliferative and secretory phases of the cycle. However, the levels of occupied nuclear receptors were significantly higher in the proliferative than in the secretory phase. The levels of total and occupied nuclear receptors in pregnancy at term were similar to those found during the proliferative phase and appeared to decrease somewhat during labor, although the differences were not statistically significant.

Cytoplasmic and nuclear progestin receptors in human myometrium during the menstrual cycle and in pregnancy at term

Exchange assays have been developed for the determination of the total progestin in receptor sites (unoccupied and occupied with endogenous hormone) in the cytosol and nuclei of human myometrium using radiolabeled R5020 (17,21-dimethyl-19-nor-4,9-pregnadiene-3,20-dione) as ligand. These assays have been applied to the measurement of cytosol and nuclear progestin receptor sites in the myometrium during the menstrual cycle and in pregnancy at term. Both the cytosol receptor levels as well as the sum of cytosol and nuclear receptor levels were highest during the proliferative phase of the cycle, dropped moderately but significantly in the secretory phase, and decreased markedly in pregnancy at term. Despite the marked drop in cytosol receptor levels, nuclear receptor levels in pregnancy at term were similar to those observed in the proliferative or secretory phase. In addition, the fraction of the total cellular receptor that was associated with the nucleus increased from 5.5% in the proliferative phase to 60% in pregnancy at term. The decrease in cytosol progestin receptor concentration as well as the relative increase in nuclear localization of the receptor in human myometrium in pregnancy at term may be related to the high circulating progesterone levels.