Heart failure and the risk of left atrial thrombus formation in patients with atrial fibrillation and atrial flutter: insights from the LATTEE registry

Background

The aim of the study was to evaluate the prevalence of left atrial thrombus (LAT) on transesophageal echocardiography (TEE) in patients with atrial fibrillation and atrial flutter (AF/AFl) with reference to the presence of heart failure (HF) and its subtypes.

Methods

The research is a substudy of multicenter, prospective, observational Left Atrial Thrombus on Transesopahgeal Echocardiography (LATTEE) registry, which comprised 3109 consecutive patients with AF/AFl undergoing TEE prior to direct current cardioversion or catheter ablation. TEE parameters, including presence of LAT, were compared between patients with and without HF, as well as different subtypes of HF, including HF with preserved (HFpEF), mid-range (HFmrEF) and reduced ejection fraction (HFrEF).

Results

HF was diagnosed in 1336 patients (43%). HF patients had higher prevalence of LAT than non-HF patients (12.8% vs. 4.4%, P<0.001). The rate of LAT increased with the more advanced type of systolic dysfunction (HFrEF vs. HFmrEF vs. HFpEF: 20.3% vs. 10.5% vs. 7.4%, P<0.001; Figure 1). Univariate analysis revealed that HFrEF (OR 4.13, 95% CI: 3.13–5.46) but not HFmrEF or HFpEF predicted the presence of LAT. Multivariable logistic regression indicated that left ventricular ejection fraction (unit OR=0.94 per 1%, 95% CI: 0.93–0.95) was an independent predictor of LAT formation. Receiver operator characteristic analysis showed LVEF ≤48% predicted presence of LAT (AUC=0.74, P<0.0001).

Conclusion

The diagnosis of HFrEF, but not HFpEF, confers a considerable risk of LAT presence despite widespread utilization of adequate anticoagulation in the assessed population. TEE should be considered in these patients prior to cardioversion or catheter ablation despite adequate oral anticoagulation.

Funding Acknowledgement

Type of funding sources: None.

The impact of marathon running on atrial remodeling in male and female amateur athletes assessed by three-dimensional echocardiography

Introduction

Endurance athletes have an increased risk of atrial remodeling and atrial arrhythmias. However, data regarding atrial adaptation to physical exercise in non-elite athletes are limited. We aimed to assess exercise-induced alternations in atrial morphology and function in male and female amateur marathon runners, using real-time three-dimensional (3D) echocardiography.

Methods

The study group consisted of 40 male (39±8 years) and 27 female (40±7 years) amateur athletes. 3D echocardiography was performed 2–3 weeks before (Stage 1) and immediately after (Stage 2) the marathon run. Right (RA) and left atrial (LA) remodeling was assessed by volumetric measures, total ejection fraction (EF) and volume (EV). Speckle tracking was used to determine the temporal evaluation of atrial function by strain analysis.

Results

The main results are presented in Table 1. At rest, male athletes demonstrated greater RA size and decreased RA contractility, as assessed by EF and atrial strains, in comparison to females. At Stage 1, LA morphology and function did not differ significantly between genders. After the marathon, a remarkable increase in RA maximal volume (RAVmax, 32.9±8.6 vs. 36.4±8.2 ml/m2, p=0.016) and RAEF (49.5±9.7 vs. 57.3±9.2%, p=0.002) was observed only in female athletes (p<0.05 for both interactions sex and stage). Whereas in male runners, LA measures, such as LAVmax (30.7±6.4 vs. 26.8±6.2 ml/m2, p=0.007), LAEF (56.7±4.3 vs. 52.7±5.3%, p=0.037) and LA conduit strain (LAScd, −18.7±8 vs. −13.6±8%, p=0.045), significantly decreased postrace. This observation was absent in females (p<0.05 for all interactions sex and stage).

Conclusions

In amateur athletes, marathon running promotes biatrial remodelling with significant gender discrepancies. Females are more susceptible to exercise-induced morphological and functional changes of RA, while postrace alternations in males concern principally LA. 3D echocardiography of the atria is a useful indicator of exercise capacity, not only in elite, but also in amateur athletes.

Funding Acknowledgement

Type of funding sources: None.

Exercise-induced changes of ventricular function in male and female amateur marathon runners as assessed by three-dimensional echocardiography

Introduction

The long-term endurance training is associated with an increased risk of both right (RV) and left ventricular (LV) dysfunction. However, males and females exhibit different cardiac adaptation to exercise. The aim of our study was to evaluate three-dimensional (3D) echocardiographic parameters of ventricular function before and after the marathon in male and female amateur athletes, and compare them between sexes.

Methods

The study included 40 male (39±8 years) and 27 female (40±7 years) amateur athletes. Echocardiography was performed 2–3 weeks before (Stage 1) and immediately after (Stage 2) the marathon run. RV and LV area and function were assessed using standard and 3D echocardiography.

Results

After the marathon, there was a significant increase in the RV size (indexed RV end-diastolic volume, 51.1±12.0 vs. 59.0±9.1 ml/m2, p=0.003 in males; 48.8±11.0 vs. 60.0±11.1 ml/m2, p<0.001 in females), with a decrease in the LV dimensions (indexed LV end-diastolic volume, 57.1±11.9 vs. 53.0±9.4 ml/m2, p=0.026 in males; 66.2±7.9 vs. 60.1±9.5 ml/m2, p=0.001 in females). RV systolic contractility, as assessed by ejection fraction (EF) and fractional area change (FAC), significantly decreased at Stage 2 in both studied groups, while post-race decrease in LVEF was observed only in males (p<0.05 for the interaction sex and stage).

Conclusions

In both male and female amateur athletes, marathon running resulted in RV dilatation and reduction in function, with concomitant decrease in LV dimensions. However, 3D analysis revealed that strenuous exercise alters LV systolic function to a greater degree in men relative to women.

Funding Acknowledgement

Type of funding sources: None.

562 Can 2D speckle tracking echocardiography have an additional impact on prediction of hospitalizations due to heart failure decompensation in patients with ischemic left ventricular systolic dysfunction

Funding Acknowledgements

NA

Background

Despite advancements in medical therapy and device-based treatment, heart failure (HF) continues to impose enormous burden for both patients and health care system worldwide. Hospitalizations due to HF decompensation is well-known cause of mortality.

Objectives were to verify whether 2D speckle tracking echocardiography (2D STE) provides independently of other well-known clinical and echocardiographic parameters, information on the risk of HF decompensation in patients with left ventricular systolic dysfunction of ischemic origin.

Materials and Methods

In 193 stable ischemic HF patients with left ventricular ejection fraction (LVEF) ≤ 50%, global longitudinal strain (GLS), as well as other echocardiographic (GE VIVID E9, EchoPAC v201) and well-known clinical parameters were analyzed. During 34 (14 – 71) months of follow-up, 58 patients were hospitalized due to HF decompensation (EVENT).

Results

LVEF, GLS, diastolic function and well-known clinical parameters (age, renal function, hemoglobin, brain natriuretic peptide level, history of diabetes, diuretic treatment and the absence of beta-blockers), as well as cut-off values of these parameters identified in ROC analysis were significantly associated with the risk of EVENT in univariate Cox hazard regression analysis (Table). GLS value of -9.4% was the most accurate predictor of EVENT (AUC 80.7% [CI 57.6 – 100%]), whereas other parameters were characterized by lower discriminatory power. In multivariate Cox analyses GLS of -9.4% was still a significant predictor of the EVENT.

Conclusions

2D STE can provide additional information, independently of other well-known clinical and echocardiographic parameters, on the risk of HF decompensation in the patients with left ventricular systolic dysfunction of ischemic origin. GLS value worse than -9.4% can identify the patients with higher risk of this EVENT.

Hazard Ratio 95% CI p Age ≥ 71 yo 2.48 1.46 - 4.23 <0.001 GFR ≤ 30 ml/min/1.73 m² 4.67 1.65 - 13.22 <0.004 Hemoglobin ≤ 14.7 g/dl 3.02 1.19 - 7.70 <0.020 BNP ≥ 214 pg/ml 2.64 1.31 - 5.31 <0.007 LVEF ≤ 32% 2.76 1.55 - 4.90 <0.001 GLS ≥ -9.4% 15.16 1.81 - 56.91 <0.012 E/A ≥ 2.0 8.64 1.91 - 39.05 0.005

Pluto's Interaction With Energetic Heliospheric Ions

Pluto energies of a few kiloelectron volts and suprathermal ions with tens of kiloelectron volts and above. We measure this population using the Pluto Energetic Particle Spectrometer Science Investigation (PEPSSI) instrument on board the New Horizons spacecraft that flew by Pluto in 2015. Even though the measured ions have gyroradii larger than the size of Pluto and the cross section of its magnetosphere, we find that the boundary of the magnetosphere is depleting the energetic ion intensities by about an order of magnitude close to Pluto. The intensity is increasing exponentially with distance to Pluto and reaches nominal levels of the interplanetary medium at about 190R _P distance. Inside the wake of Pluto, we observe oscillations of the ion intensities with a periodicity of about 0.2 hr. We show that these can be quantitatively explained by the electric field of an ultralow-frequency wave and discuss possible physical drivers for such a field. We find no evidence for the presence of plutogenic ions in the considered energy range.

Influence of pelvic volume on surgical outcome after low anterior resection for rectal cancer

BACKGROUND

Low anterior resection (LAR) for rectal cancer is a potentially challenging operation due to limited space in the pelvis. CT pelvimetry allows to quantify pelvic space, so that its relationship with outcome after LAR may be assessed. Studies investigating this, however, yielded conflicting results. We hypothesized that a small pelvis is associated with a higher rate of incomplete mesorectal excision, anastomotic leakages, and increased rate of urinary dysfunction in patients operated for rectal cancer.

METHODS

In a single-center retrospective analysis, we studied 74 patients that underwent LAR for rectal cancer with primary anastomosis. Thin-layered multi-slice CT datasets were used for slice by slice depiction of the inner pelvic surface, and the inner pelvic volume was automatically compounded. The primary outcome was quality of total mesorectal excision (TME; Mercury grading); secondary outcomes were anastomotic leakage and urinary dysfunction with regard to pelvic dimensions. Univariate analyses and multiple logistic regression analyses were performed for the primary and the secondary outcomes.

RESULTS

Shorter obstetric conjugate diameters were associated with a higher probability of a worse TME quality (110.8 ± 10.2 vs. 105.0 ± 8.6 mm; OR 0.85; 95% CI 0.73-0.99; p = 0.038). Short interspinous distance showed a trend towards an increased risk for deteriorated TME quality (OR 0.88; 95% CI 0.76-1.0; p = 0.06). Anastomotic leakage was associated with anemia (OR 2.77; 95% CI 1.0-7.7; p = 0.047). Association between pelvic diameters or pelvic volume and anastomotic leakage or urinary dysfunction was not observed. Perioperative blood transfusions were administered more often in patients with postoperative urinary dysfunction (OR 17.67; 95% CI 2.44-127.7; p = 0.004).

CONCLUSION

Shorter obstetric conjugate diameter might be a risk factor for incompleteness of total mesorectal excision. Anastomotic leakage seems to be influenced more by clinical factors such as anemia rather than pelvic dimensions. Further studies have to prove the influence of pelvic diameter on local recurrence of rectal cancer after LAR.

Modelling the growth of plants with a uniform growth logistics

BACKGROUND AND AIMS

The increment model has previously been used to describe the growth of plants in general. Here, we examine how the same logistics enables the development of different superstructures.

METHODS

Data from the literature are analyzed with the increment model. Increments are growth-invariant molecular clusters, treated as heuristic particles. This approach formulates the law of mass action for multi-component systems, describing the general properties of superstructures which are optimized via relaxation processes.

RESULTS

The daily growth patterns of hypocotyls can be reproduced implying predetermined growth invariant model parameters. In various species, the coordinated formation and death of fine roots are modeled successfully. Their biphasic annual growth follows distinct morphological programs but both use the same logistics. In tropical forests, distributions of the diameter in breast height of trees of different species adhere to the same pattern. Beyond structural fluctuations, competition and cooperation within and between the species may drive optimization.

CONCLUSION

All superstructures of plants examined so far could be reproduced with our approach. With genetically encoded growth-invariant model parameters (interaction with the environment included) perfect morphological development runs embedded in the uniform logistics of the increment model.

Partial Blindness to Submicron Topography in NF1 Haploinsufficient Cultured Fibroblasts Indicates a New Function of Neurofibromin in Regulation of Mechanosensoric

Cells sense physical properties of their extracellular environment and translate them into biochemical signals. In this study, cell responses to surfaces with submicron topographies were investigated in cultured human NF1 haploinsufficient fibroblasts. Age-matched fibroblasts from 8 patients with neurofibromatosis type 1 (NF1(+/-)) and 9 controls (NF1(+/+)) were cultured on surfaces with grooves of 200 nm height and lateral distance of 2 μm. As cellular response indicator, the mean cell orientation along microstructured grooves was systematically examined. The tested NF1 haploinsufficient fibroblasts were significantly less affected by the topography than those from healthy donors. Incubation of the NF1(+/-) fibroblasts with the farnesyltransferase inhibitor FTI-277 and other inhibitors of the neurofibromin pathway ameliorates significantly the cell orientation. These data indicate that NF1 haploinsufficiency results in an altered response to specific surface topography in fibroblasts. We suggest a new function of neurofibromin in the sensoric mechanism to topographies and a partial mechanosensoric blindness by NF1 haploinsufficiency.

A comparative electrographic analysis of the effect of sec-butyl-propylacetamide on pharmacoresistant status epilepticus

Better treatment of status epilepticus (SE), which typically becomes refractory after about 30 min, will require new pharmacotherapies. The effect of sec-butyl-propylacetamide (SPD), an amide derivative of valproic acid (VPA), on electrographic status epilepticus (ESE) was compared quantitatively to other standard-of-care compounds. Cortical electroencephalograms (EEGs) were recorded from rats during ESE induced with lithium-pilocarpine. Using a previously-published algorithm, the effects of SPD on ESE were compared quantitatively to other relevant compounds. To confirm benzodiazepine resistance, diazepam (DZP) was shown to suppress ESE when administered 15 min after the first motor seizure, but not after 30 min (100mg/kg). VPA (300 mg/kg) also lacked efficacy at 30 min. SPD (130 mg/kg) strongly suppressed ESE at 30 min, less after 45 min, and not at 60 min. At a higher dose (180 mg/kg), SPD profoundly suppressed ESE at 60 min, similar to propofol (100mg/kg) and pentobarbital (30 mg/kg). After 4-6h of SPD-induced suppression, EEG activity often overshot control levels at 7-12h. Valnoctamide (VCD, 180 mg/kg), an SPD homolog, was also efficacious at 30 min. SPD blocks pilocarpine-induced electrographic seizures when administered at 1h after the first motor seizure. SPD has a faster onset and greater efficacy than DZP and VPA, and is similar to propofol and pentobarbital. SPD and structurally similar compounds may be useful for the treatment of refractory ESE. Further development and use of automated analyses of ESE may facilitate drug discovery for refractory SE.

On the structure-bounded growth processes in plant populations

If growing cells in plants are considered to be composed of increments (ICs) an extended version of the law of mass action can be formulated. It evidences that growth of plants runs optimal if the reaction-entropy term (entropy times the absolute temperature) matches the contact energy of ICs. Since these energies are small, thermal molecular movements facilitate via relaxation the removal of structure disturbances. Stem diameter distributions exhibit extra fluctuations likely to be caused by permanent constraints. Since the signal-response system enables in principle perfect optimization only within finite-sized cell ensembles, plants comprising relatively large cell numbers form a network of size-limited subsystems. The maximal number of these constituents depends both on genetic and environmental factors. Accounting for logistical structure-dynamics interrelations, equations can be formulated to describe the bimodal growth curves of very different plants. The reproduction of the S-bended growth curves verifies that the relaxation modes with a broad structure-controlled distribution freeze successively until finally growth is fully blocked thus bringing about "continuous solidification".

Correlation between critical temperature and strength of small-scale bcc pillars

Microcompression tests were performed on focused-ion-beam-machined micropillars of several body-centered-cubic metals (W, Mo, Ta, and Nb) at room temperature. The relationship between yield strength and pillar diameter as well as the deformation morphologies were found to correlate with a parameter specific for bcc metals, i.e., the critical temperature T(c). This finding sheds new light on the phenomenon of small-scale plasticity in largely unexplored non-fcc metals.

Higher efficiency of thymine-adenine clamp-modified single-stranded oligonucleotides in targeted nucleotide sequence correction is not correlated with lower intracellular degradation

Specific single-stranded oligonucleotides can induce targeted nucleotide sequence correction in eukaryotic genes in vitro and in vivo. Our model for investigating the reasons for the low correction rates achieved by this method is the correction of a point mutation in the hypoxanthine-guanine phosphoribosyltransferase gene (hprt) in the cell line V79-151. Using single-stranded phosphorothioate-modified oligonucleotides, the correction rates of this hprt mutation were low but always reproducible. One reason for low exchange rates may be fast intracellular degradation of the oligonucleotides. Therefore we compared the exchange rates of different 3' and 5' end-modified oligonucleotides with their degradation rates. Thymine-adenine (TA) repeat (clamp)-modified oligonucleotides showed higher correction rates than those with a guanine-cytosine (GC) clamp and 5' clamps induced higher correction rates than clamps at the 3' end. Experiments on the stability of the most effective 5'-TA and 3'-TA clamp-modified oligonucleotide indicated rapid cleavage and the occurrence of shortened oligonucleotides in the presence of cytoplasmic and nuclear extracts. The phosphorothioate-modified oligonucleotides were more stable, but their correction rates were lower. We suggest that there is no direct correlation between the biological stability of the full-length oligonucleotides and the exchange rates achieved.

Higher efficiency of thymine-adenine clamp-modified single-stranded oligonucleotides in targeted nucleotide sequence correction is not correlated with lower intracellular degradation

Specific single-stranded oligonucleotides can induce targeted nucleotide sequence correction in eukaryotic genes in vitro and in vivo. Our model for investigating the reasons for the low correction rates achieved by this method is the correction of a point mutation in the hypoxanthine-guanine phosphoribosyltransferase gene (hprt) in the cell line V79-151. Using single-stranded phosphorothioate-modified oligonucleotides, the correction rates of this hprt mutation were low but always reproducible. One reason for low exchange rates may be fast intracellular degradation of the oligonucleotides. Therefore we compared the exchange rates of different 3' and 5' end-modified oligonucleotides with their degradation rates. Thymine-adenine (TA) repeat (clamp)-modified oligonucleotides showed higher correction rates than those with a guanine-cytosine (GC) clamp and 5' clamps induced higher correction rates than clamps at the 3' end. Experiments on the stability of the most effective 5'-TA and 3'-TA clamp-modified oligonucleotide indicated rapid cleavage and the occurrence of shortened oligonucleotides in the presence of cytoplasmic and nuclear extracts. The phosphorothioate-modified oligonucleotides were more stable, but their correction rates were lower. We suggest that there is no direct correlation between the biological stability of the full-length oligonucleotides and the exchange rates achieved.

The general growth logistics of cell populations

An increment model based on thermodynamics lays bare that the cell size distributions of archaea, prokaryotes and eukaryotes are optimized and belong to the same universal class. Yet, when a cell absorbs mass or signals are processed, these conditions are disturbed. Relaxation re-installs ideal growth conditions via an exponential process with a rate that slows down with the cell size. In a growing ensemble, a distribution of relaxation modes comes in existence, exactly defined by the universal cell size distribution. The discovery of nano-mechanic acoustic activities in cells led us to assume that in a growing ensemble acoustic signals may contribute significantly to the transmission of essential information about growth-induced disturbances to all cells, initiating that way coordinated relaxation. The frequency increases with the cell number shortening the period between successive signals. The completion of rearrangements occurring at a constant rate is thus progressively impaired, until cellular growth stops, totally. Due to this phenomenon, the so-called "relaxation-frequency-dispersion" cell colonies should exhibit a maximum cell number. In populations with large cell numbers, subsystems, behaving similar-like colonies, should form network-like patterns. Based on these ideas, we formulate equations that describe the growth curves of all cell types, verifying that way the general nature of the growth logistics.

Stationary cell size distributions and mean protein chain length distributions of Archaea, Bacteria and Eukaryotes described with an increment model in terms of irreversible thermodynamics

In terms of an increment model irreversible thermodynamics allows to formulate general relations of stationary cell size distributions observed in growing colonies. The treatment is based on the following key postulates: i) The growth dynamics covers a broad spectrum of fast and slow processes. ii) Slow processes are considered to install structural patterns that operate in short periods as temporary stationary states of reference in the sense of irreversible thermodynamics. iii) Distortion during growth is balanced out via the many fast processes until an optimized stationary state is achieved. The relation deduced identifies the numerous different stationary patterns as equivalents, predicting that they should fall on one master curve. Stationary cell size distributions of different cell types, like Hyperphilic archaea, E. coli (Prokaryotes) and S. cerevisiae (Eukaryotes), altogether taken from the literature, are in fact consistently described. As demanded by the model they agree together with the same master curve. Considering the "protein factories" as subsystems of cells the mean protein chain length distributions deduced from completely sequenced genomes should be optimized. In fact, the mean course can be described with analogous relations as used above. Moreover, the master curve fits well to the patterns of different species of Archaea, Bacteria and Eukaryotes. General consequences are discussed.

Urinary Bladder Cancer: Preoperative Nodal Staging with Ferumoxtran-10–enhanced MR Imaging

PURPOSE

To prospectively evaluate ferumoxtran-10-enhanced magnetic resonance (MR) imaging for nodal staging in patients with urinary bladder cancer.

MATERIALS AND METHODS

Fifty-eight patients with proved bladder cancer were enrolled. Results of MR imaging performed before and after injection of ferumoxtran-10 were compared with histopathologic results in surgically removed lymph nodes. High-spatial-resolution three-dimensional T1-weighted magnetization-prepared rapid acquisition gradient-echo (voxel size, 1.4 x 1.4 x 1.4 mm) and T2*-weighted gradient-echo (voxel size, 0.8 x 0.8 x 3.0 mm) sequences were performed before and 24 hours after injection of ferumoxtran-10 (2.6 mg iron per kilogram of body weight). On precontrast images, lymph nodes were defined as malignant by using size and shape criteria (round node, >8 mm; oval, >10 mm axial diameter). On postcontrast images, nodes were considered benign if there was homogeneous decrease in signal intensity and malignant if decrease was absent or heterogeneous. Qualitative evaluation was performed on a node-to-node basis. Sensitivity, specificity, predictive values, and accuracy were evaluated with logistic regression analysis.

RESULTS

In 58 patients, 172 nodes imaged with use of ferumoxtran-10 were matched and correlated with results of node dissection. Of these, 122 were benign and 50 were malignant. With nodal size and shape criteria, accuracy, sensitivity, specificity, and positive and negative predictive values on precontrast images were 92%, 76%, 99%, 97%, and 91%, respectively; corresponding values on postcontrast images were 95%, 96%, 95%, 89%, and 98%. In the depiction of pelvic metastases, sensitivity and negative predictive value improved significantly at postcontrast compared with those at precontrast imaging, from 76% to 96% (P < .001) and from 91% to 98% (P < .01), respectively. At postcontrast imaging, metastases (4-9 mm) were prospectively found in 10 of 12 normal-sized nodes (<10 mm); these metastases were not detected on precontrast images. Postcontrast images also showed lymph nodes that were missed at pelvic node dissection in two patients.

CONCLUSION

Ferumoxtran-10-enhanced MR imaging significantly improves nodal staging in patients with bladder cancer by depicting metastases even in normal-sized lymph nodes.

Laryngopharyngitis by Corynebacterium ulcerans

A 71-year-old female patient was hospitalized with membranous laryngopharyngitis typical of classical diphtheria. A toxigenic strain of Corynebacterium ulcerans was isolated from the throat. The patient was treated for 6 days with amoxicillin-clavulanic acid and recovered without complications. This second reported case of diphtheric laryngopharyngitis caused by C. ulcerans in Switzerland is a reminder that C. ulcerans should be included as a possible agent in patients with classical diphtheria symptoms.

Spinal neurofibromatosis without café-au-lait macules in two families with null mutations of the NF1 gene

Spinal neurofibromatosis (SNF) is considered to be an alternative form of neurofibromatosis, showing multiple spinal tumors and café-au-lait macules. Involvement of the neurofibromatosis type 1 (NF1) locus has been demonstrated, by linkage analysis, for three families with SNF. In one of them, a cosegregating frameshift mutation in exon 46 of the NF1 gene was identified. In the present study, we report four individuals from two families who carry NF1 null mutations that would be expected to cause NF1. Three patients have multiple spinal tumors and no café-au-lait macules, and the fourth has no clinical signs of NF1. In the first family, a missense mutation (Leu2067Pro) in NF1 exon 33 was found, and, in the second, a splice-site mutation (IVS31-5A-->G) enlarging exon 32 by 4 bp at the 5' end was found. The latter mutation has also been observed in an unrelated patient with classical NF1. Both NF1 mutations cause a reduction in neurofibromin of approximately 50%, with no truncated protein present in the cells. This demonstrates that typical NF1 null mutations can result in a phenotype that is distinct from classical NF1, showing only a small spectrum of the NF1 symptoms, such as multiple spinal tumors, but not completely fitting the current clinical criteria for SNF. We speculate that this phenotype is caused by an unknown modifying gene that compensates for some, but not all, of the effects caused by neurofibromin deficiency.

Is the distribution of dermal neurofibromas in neurofibromatosis type 1 (NF1) related to the pattern of the skin surface temperature?

The formation of dermal neurofibromas is a hallmark of the neurofibromatosis type 1 (NF1). A total loss of the NF1 gene product by stochastic events inactivating the wild type allele in Schwann cells should precede the development of neurofibromas. Dermal neurofibromas tend to be located mainly on the surface of the trunk and not in the body periphery. This distribution partly resembles the density of sensitive nerve endings in the epidermis. Our hypothesis is that a better correlation concerns the pattern of normal body surface temperature. According to our clinical observations we assume that in skin areas with higher temperatures the number of visible dermal neurofibromas is higher than in colder areas such as the arms/legs or nose. It is known that differences in temperature are able to determine differentiation. We suggest that the regulation of skin temperature is also involved in the formation of NF1 dermal neurofibromas and is related to the intrafamilial variability in NF1.

[Not Available]

The beginning of the 19th century saw the definite separation of the medical discourse from the Enlightened public discourse on the knowledge of human nature. Especially in the emerging field of psychiatry new definitions of the interaction between somatic and psychic processes occurred. In this context the psychiatric "moral treatment" (psychische Kurmethode) meant a direct therapeutical intervention into these processes. Pain as a heroic means that worked directly on the nerve-system gained a key role to restore the mad patient's lost consciousness of the self. This physiological concept of pain, mainly represented by Johann Christian Reil who operated in a new space of medical knowledge, came into conflict with changing attitudes and a new sensitivity of the middle classes to corporal punishment and violence at the beginning of the 19th century.

Spinal cord ischaemia after stent-graft treatment for infra-renal abdominal aortic aneurysms. Analysis of the Eurostar database

OBJECTIVES

to evaluate the prevalence and the possible causes of spinal cord ischaemia (SCI) following endovascular abdominal aneurysm repair (EVAR). Differences in the incidence of this complication between endovascular treatment and published series following conventional treatment were assessed.

DESIGN

analysis of patients enrolled in the EUROSTAR collaborators registry.

MATERIALS AND METHODS

2862 patients operated between July 1994 and July 2000 were analysed. Patient characteristics, aneurysm morphology, procedure characteristics and potential causative factors with particular interference with pelvic circulation or pelvic embolisation were related to the risk of SCI.

RESULTS

six patients (0.21%) were identified with postoperative symptoms of SCI: one complete spinal cord infarction (type I), two anterior spinal artery syndromes (type II) and three combinations of root lesions and centromedullary infarcts (type III). In the patients with type I or II lesions (3/6) no regression of neurological symptoms was noted, whereas the patients with type III lesions (3/6) had partial regression of symptoms in two cases and a full neurological recovery in one case. There was a significant correlation between emboli (p < 0.001) and coil embolisation of hypogastric or lumbar arteries (p < 0.029) and the development of SCI.

CONCLUSIONS

SCI is equally rare following open aortic surgery or EVAR. Microembolism is the probable cause. SCI should be mentioned when taking informed consent.

Virological and immunological characteristics of HIV treatment failure

BACKGROUND

Resistance to antiretroviral treatment is prevalent. There is limited knowledge of the determinants of disease evolution in subjects infected with multidrug-resistant HIV (MDR-HIV).

METHODS

Infectivity, replication, chemokine receptor usage, and env, gag, protease and reverse transcriptase sequence analysis was performed for MDR-HIV isolates from 14 HIV-infected individuals and compared to wild-type HIV isolates from individuals naive to antiretroviral treatment. Expression of CD45RO/RA, Ki67 and interferon-gamma and CD4 proliferative response to various antigens was determined for individuals infected with MDR-HIV and compared to that in individuals with optimal suppression of viral replication.

RESULTS

Infectivity and replication are diminished for various MDR-HIV isolates, usually in the context of an increase in CD4 and CD4+CD45RA+ T-cell counts. However, a number of MDR-HIV isolates are associated with high in vivo viraemia and pronounced immunosuppression, and display in vitro levels of infectivity and replication comparable to those of wild-type strains. No specific genetic sequence or chemokine receptor usage predicted the fitness of an MDR isolate.

CONCLUSIONS

Despite the biological diversity of resistant viruses and the range of host responses observed, our descriptive analysis indicates that viral factors play a role in determining the degree of immune damage observed in the context of MDR-HIV infection.

Segmental neurofibromatosis is caused by somatic mutation of the neurofibromatosis type 1 (NF1) gene

Segmental neurofibromatosis (NF) is generally thought to result from a postzygotic NF1 (neurofibromatosis type 1) gene mutation. However, this has not yet been demonstrated at the molecular level. Using fluorescence in situ hybridisation (FISH) we identified an NF1 microdeletion in a patient with segmental NF in whom café-au-lait spots and freckles are limited to a single body region. The mutant allele was present in a mosaic pattern in cultured fibroblasts from a café-au-lait spot lesion, but was absent in fibroblasts from normal skin as well as in peripheral blood leukocytes. These findings prove the hypothesis that the molecular basis of segmental cutaneous NF is a mutation in the NF1 gene and that the regional distribution of manifestations reflects different cell clones, commensurate with the concept of somatic mosaicism.

Initiation of antiretroviral therapy during primary HIV-1 infection induces rapid stabilization of the T-cell receptor beta chain repertoire and reduces the level of T-cell oligoclonality

Major T-cell receptor beta chain variable region (TCRBV) repertoire perturbations are temporally associated with the down-regulation of viremia during primary human immunodeficiency virus (HIV) infection and with oligoclonal expansion and clonal exhaustion of HIV-specific cytotoxic T lymphocytes (CTLs). To determine whether initiation of antiretroviral therapy (ART) or highly active antiretroviral therapy (HAART) during primary infection influences the dynamics of T-cell-mediated immune responses, the TCRBV repertoire was analyzed by semiquantitative polymerase chain reaction in serial blood samples obtained from 11 untreated and 11 ART-treated patients. Repertoire variations were evaluated longitudinally. Stabilization of the TCRBV repertoire was more consistently observed in treated as compared with untreated patients. Furthermore, the extent and the rapidity of stabilization were significantly different in treated versus untreated patients. TCRBV repertoire stabilization was positively correlated with the slope of HIV viremia in the treated group, suggesting an association between repertoire stabilization and virologic response to treatment. To test whether stabilization was associated with variations in the clonal complexity of T-cell populations, T-cell receptor (TCR) heteroduplex mobility shift assays (HMAs) were performed on sequential samples from 4 HAART-treated subjects. Densitometric analysis of HMA profiles showed a reduction in the number of TCR clonotypes in most TCRBV families and a significant decrease in the total number of clonotypes following 7 months of HAART. Furthermore, a biphasic decline in HIV-specific but not heterologous CTL clones was observed. This indicates that ART leads to a global reduction of CD8(+) T-cell oligoclonality and significantly modulates the mobilization of HIV-specific CTL during primary infection. (Blood. 2000;95:1743-1751)

AIDS-related opportunistic illnesses occurring after initiation of potent antiretroviral therapy: the Swiss HIV Cohort Study

CONTEXT

Acquired immunodeficiency syndrome-related opportunistic illnesses (Ols) continue to occur after initiation of potent antiretroviral therapy in patients with human immunodeficiency virus (HIV) infection. Risk factors for clinical progression to Ols during potent therapy are not well defined.

OBJECTIVE

To examine the incidence of and risk factors for Ols among patients treated with potent antiretroviral therapy in a population-based study.

DESIGN

The Swiss HIV Cohort Study, a prospective cohort study of adult HIV-infected persons.

SETTING

Seven study centers throughout Switzerland.

PATIENTS

A total of 2410 cohort study participants with a potential follow-up of at least 15 months after starting potent therapy between September 1995 and December 1997.

MAIN OUTCOME MEASURES

Disease-specific incidence of Ols during the 6 months preceding potent antiretroviral therapy and at 3 intervals after initiating therapy; risk factors for development of Ols during therapy.

RESULTS

Of the 2410 participants, 143 developed 186 Ols after initiation of potent antiretroviral therapy. Incidence of any OI decreased from 15.1 per 100 person-years in the 6 months before therapy to 7.7 in the first 3 months after starting treatment, 2.6 in the following 6 months, and 2.2 per 100 person-years between 9 and 15 months. Reductions in incidence ranged from 38% per month for Kaposi sarcoma (P<.001) to 5% per month for non-Hodgkin lymphoma (P = .31). Baseline CD4 cell count continued to predict the risk of disease progression after initiating potent therapy. Compared with CD4 cell counts above 200 x 10(6)/L, the hazard ratio for developing Ols was 2.5 (95% confidence interval [CI], 1.4-4.5) for counts between 51 and 200 x 10(6)/L and 5.8 (95% CI, 3.2-10.5) for counts below 51 x 10(6)/L at baseline. Independent of baseline CD4 cell count, a rise in CD4 cell count by 50 x 10(6)/L or more and undetectable HIV-1 RNA in plasma (<400 copies/mL) by 6 months reduced risk of subsequent events, with hazard ratios of 0.32 (95% CI, 0.20-0.52) and 0.39 (0.24-0.65), respectively.

CONCLUSIONS

Our data indicate that the risk of developing an OI for a person receiving potent antiretroviral therapy is highest during the initial months of therapy. Baseline CD4 cell count and immunologic and virologic response to treatment were strong predictors of disease progression in patients receiving potent therapy. Individuals with CD4 cell counts of 50 x 10(6)/L or below may need close clinical surveillance after initiation of potent therapy.

On the lysosomal degradation of neurofibromin and its phosphorylation in cultured melanocytes

Neurofibromatosis type 1 (NF1) is one of the most common inherited disorders in humans. Most of the NF1 gene mutations result in a reduction of the amount of neurofibromin to about 50%. Recently, we found that the level of neurofibromin can be regulated post-translationally through the alteration of its half-life. Here, we investigated whether lysosomes are involved in this post-translational regulation in cultured melanocytes of NF1 patients and controls. When the lysosomal degradation was inhibited by chloroquine, an increase of neurofibromin by a factor of 2 to 3, correlating with an increased half-life, was measured. Incubation with phosphoprotein-phosphatase inhibitors also increased the neurofibromin content in melanocytes. Investigations on phosphorylation of neurofibromin revealed a basal phosphorylation in melanocytes cultured with growth factor-deprived medium that increased upon incubation with the growth stimulators PMA or bFGF. Because both factors are also able to increase the half-life of neurofibromin, we suggest its phosphorylation to be an important step in protecting neurofibromin against specific lysosomal degradation.

Posttranslational regulation of neurofibromin content in melanocytes of neurofibromatosis type 1 patients

Neurofibromatosis type 1 (NF1) is a common autosomal dominantly inherited disorder characterized by neurofibromas and café-au-lait macules. Most of the NF1 gene germline mutations result in a reduction in the level of neurofibromin. As shown recently, the neurofibromin level can be regulated posttranslationally through alteration of the protein half-life. This raises the question as to whether this type of regulation is also operating in cultured melanocytes of NF1 patients especially in melanocytes derived from café-au-lait macules. In melanocytes cultured without phorbol 12-myristate 13-acetate (PMA) the neurofibromin half-lives were 24 h (healthy controls, MC), 26 h (apparently healthy skin of NF1 patients, MNFS) and 25 h (café-au-lait macules of NF1 patients, MNFC). In PMA-stimulated cells the neurofibromin half-lives were 68 h (MC) and 73 h (MNFS) whereas it was 45 h in melanocytes derived from NF1 café-au-lait macules. The amount of NF1 mRNA was not altered under these culture conditions as shown by competitive RT-PCR. We speculate that this regulation is involved in the formation of some NF1 symptoms, for instance in the formation of café-au-lait macules.

EVI2B, a gene lying in an intron of the neurofibromatosis type 1 (NF1) gene, is as the NF1 gene involved in differentiation of melanocytes and keratinocytes and is overexpressed in cells derived from NF1 neurofibromas

The EVI2B gene is one of three genes embedded in intron 27b of the neurofibromatosis type 1 (NF1; M. Recklinghausen) gene, which are transcribed in the direction opposite that of the NF1 gene. The function of EVI2B and its relation to NF1 symptoms is unknown. Here, the amounts of NF1 and EVI2B mRNA were investigated in detail in cells involved in NF1 manifestations as café-au-lait macules and neurofibromas. These investigations showed that aside from the NF1 gene, EVI2B is involved in melanocyte and keratinocyte differentiation. Whereas in NF1 melanocytes from café-au-lait macules, EVI2B expression was not altered, in fibroblast-like cells derived from neurofibromas, an increased level of EVI2B mRNA was found. We investigated whether this increase was attributable to an influence of NF1 gene expression on the expression of the EVI2B gene, as suggested by the fact that the EVI2B primary transcript is antisense to the NF1 primary transcript. Investigations of cells derived from patients with different amounts of NF1 pre-mRNA showed no correlation between the amount of NF1 pre-mRNA and the increased level of EVI2B mRNA.

Expression of CD28 and CD38 by CD8+ T lymphocytes in HIV-1 infection correlates with markers of disease severity and changes towards normalization under treatment. The Swiss HIV Cohort Study

The relationship between blood CD8+ T lymphocyte subsets, as defined by CD28 and CD38 expression, and plasma viraemia and CD4+ T cells in HIV-1 infection was investigated. In a cross-sectional study of 46 patients with either no or stable anti-retroviral treatment, there was a strong negative correlation between the percentage of CD8+CD28- and the percentage of CD4+ T cells (r = -0.75, P < 0.0001), and a positive correlation between absolute numbers of CD8+CD28+ and CD4+ T cells (r = 0.56, P < 0.0001). In contrast, the expression of CD38 by CD8+ T lymphocytes correlated primarily with plasma viraemia (e.g. the percentage of CD38+ in CD8bright cells, r = 0.76, P < 0.0001). In the 6 months following triple therapy initiation in 32 subjects, there was a close correlation between changes (delta) in CD8+CD28+ or CD8+CD28- and in CD4+ T cells (e.g. delta % CD8+CD28+ versus delta % CD4+, r = 0.37, P = 0.0002; delta % CD8+CD28- versus delta % CD4+, r = -0.66, P < 0.0001). A marked decline of the number of CD8+ T cells expressing CD38 was also observed. These results suggest the existence of a T cell homeostasis mechanism operating in blood with CD4+ and CD8+CD28+ cells on the one hand, and with CD8+CD28- cells on the other. In addition, the percentage of CD38+ cells in CD8+ cells, generally considered an independent prognostic factor, could merely reflect plasma viral load.