Treatment of Metaphyseal Defects in Plated Proximal Humerus Fractures with a New Augmentation Technique-A Biomechanical Cadaveric Study.

Background and Objectives: Unstable proximal humerus fractures (PHFs) with metaphyseal defects-weakening the osteosynthesis construct-are challenging to treat. A new augmentation technique of plated complex PHFs with metaphyseal defects was recently introduced in the clinical practice. This biomechanical study aimed to analyze the stability of plated unstable PHFs augmented via implementation of this technique versus no augmentation. Materials and Methods: Three-part AO/OTA 11-B1.1 unstable PHFs with metaphyseal defects were created in sixteen paired human cadaveric humeri (average donor age 76 years, range 66-92 years), pairwise assigned to two groups for locked plate fixation with identical implant configuration. In one of the groups, six-milliliter polymethylmethacrylate bone cement with medium viscosity (seven minutes after mixing) was placed manually through the lateral window in the defect of the humerus head after its anatomical reduction to the shaft and prior to the anatomical reduction of the greater tuberosity fragment. All specimens were tested biomechanically in a 25° adduction, applying progressively increasing cyclic loading at 2 Hz until failure. Interfragmentary movements were monitored by motion tracking and X-ray imaging. Results: Initial stiffness was not significantly different between the groups, p = 0.467. Varus deformation of the humerus head fragment, fracture displacement at the medial humerus head aspect, and proximal screw migration and cut-out were significantly smaller in the augmented group after 2000, 4000, 6000, 8000 and 10,000 cycles, p ≤ 0.019. Cycles to 5° varus deformation of the humerus head fragment-set as a clinically relevant failure criterion-and failure load were significantly higher in the augmented group, p = 0.018. Conclusions: From a biomechanical standpoint, augmentation with polymethylmethacrylate bone cement placed in the metaphyseal humerus head defect of plated unstable PHFs considerably enhances fixation stability and can reduce the risk of postoperative complications.

LaRA 2: parallel and vectorized program for sequence-structure alignment of RNA sequences.

BACKGROUND: The function of non-coding RNA sequences is largely determined by their spatial conformation, namely the secondary structure of the molecule, formed by Watson-Crick interactions between nucleotides. Hence, modern RNA alignment algorithms routinely take structural information into account. In order to discover yet unknown RNA families and infer their possible functions, the structural alignment of RNAs is an essential task. This task demands a lot of computational resources, especially for aligning many long sequences, and it therefore requires efficient algorithms that utilize modern hardware when available. A subset of the secondary structures contains overlapping interactions (called pseudoknots), which add additional complexity to the problem and are often ignored in available software. RESULTS: We present the SeqAn-based software LaRA 2 that is significantly faster than comparable software for accurate pairwise and multiple alignments of structured RNA sequences. In contrast to other programs our approach can handle arbitrary pseudoknots. As an improved re-implementation of the LaRA tool for structural alignments, LaRA 2 uses multi-threading and vectorization for parallel execution and a new heuristic for computing a lower boundary of the solution. Our algorithmic improvements yield a program that is up to 130 times faster than the previous version. CONCLUSIONS: With LaRA 2 we provide a tool to analyse large sets of RNA secondary structures in relatively short time, based on structural alignment. The produced alignments can be used to derive structural motifs for the search in genomic databases.

Value of Cardiopulmonary Exercise Testing in the Prognosis Assessment of Chronic Obstructive Pulmonary Disease Patients: A Retrospective, Multicentre Cohort Study.

INTRODUCTION: Chronic obstructive pulmonary disease (COPD) is one of the most common chronic diseases associated with high mortality. Previous studies suggested a prognostic role for peak oxygen uptake (VO2peak) assessed during cardiopulmonary exercise testing (CPET) in patients with COPD. However, most of these studies had small sample sizes or short follow-up periods, and despite their relevance, CPET parameters are not included in the Global Initiative for Chronic Obstructive Lung Disease (GOLD) tool for assessment of severity. OBJECTIVES: We therefore aimed to assess the prognostic value of CPET parameters in a large cohort of outpatients with COPD. METHODS: In this retrospective, multicentre cohort study, medical records of patients with COPD who underwent CPET during 2004-2017 were reviewed and demographics, smoking habits, GOLD grade and category, exacerbation frequency, dyspnoea score, lung function measurements, and CPET parameters were documented. Relationships with survival were evaluated using Kaplan-Meier analysis, Cox regression, and receiver operating characteristic (ROC) curves. RESULTS: Of a total of 347 patients, 312 patients were included. Five-year and 10-year survival probability was 75% and 57%, respectively. VO2peak significantly predicted survival (hazard ratio: 0.886 [95% confidence interval: 0.830; 0.946]). The optimal VO2peak threshold for discrimination of 5-year survival was 14.6 mL/kg/min (area under ROC curve: 0.713). Five-year survival in patients with VO2peak <14.6 mL/kg/min versus ≥ 14.6 mL/kg/min was 60% versus 86% in GOLD categories A/B and 64% versus 90% in GOLD categories C/D. CONCLUSIONS: We confirm that VO2peak is a highly significant predictor of survival in COPD patients and recommend the incorporation of VO2peak into the assessment of COPD severity.

A Novel Technique for Treatment of Metaphyseal Voids in Proximal Humerus Fractures in Elderly Patients.

Background and Objectives: The treatment of proximal humerus fractures in elderly patients is challenging, with reported high complication rates mostly related to implant failure involving screw cut-out and penetration. Metaphyseal defects are common in osteoporotic bone and weaken the osteosynthesis construct. A novel technique for augmentation with polymethylmethacrylate (PMMA) bone cement was developed for the treatment of patients in advanced age with complex proximal humerus fractures and metaphyseal voids, whereby the cement was allowed to partially cure for 5-7 min after mixing to achieve medium viscosity, and then it was manually placed into the defect through the traumatic lateral window with a volume of 4-6 mL per patient. The aim of this retrospective clinical study was to assess this technique versus autologous bone graft augmentation and no augmentation. Materials and Methods: The outcomes of 120 patients with plated Neer three- and four-part fractures, assigned to groups of 63 cases with no augmentation, 28 with bone graft augmentation and 29 with cement augmentation, were assessed in this study. DASH, CS, pain scores and range of motion were analyzed at 3, 6 and 12 months. Statistical analysis was performed with factors for treatment and age groups, Neer fracture types and follow-up periods, and with the consideration of age as a covariate. Results: DASH and CS improved following cement augmentation at three and six months compared to bone grafting, being significant when correcting for age as a covariate (p ≤ 0.007). While the age group had a significant effect on both these scores with worsened values at a higher age for non-augmented and grafted patients (p ≤ 0.044), this was not the case for cement augmented patients (p ≥ 0.128). Cement augmentation demonstrated good clinical results at 12 months with a mean DASH of 10.21 and mean CS percentage of 84.83% versus the contralateral side, not being significantly different among the techniques (p ≥ 0.372), despite the cement augmented group representing the older population with more four-part fractures. There were no concerning adverse events specifically related to the novel technique. Conclusions: This study has detailed a novel technique for the treatment of metaphyseal defects with PMMA cement augmentation in elderly patients with complex proximal humerus fractures and follow-up to one year, whereby the cement was allowed to partially cure to achieve medium viscosity, and then it was manually placed into the defect through the traumatic lateral window. The results demonstrate clinically equivalent short-term results to 6 months compared to augmentation with bone graft or no augmentation-despite the patient group being older and with a higher rate of more severe fracture patterns. The technique appears to be safe with no specifically related adverse events and can be added in the surgeon's armamentarium for the treatment of these difficult to manage fractures.

Prognostic value of cardiopulmonary exercise testing in patients with systemic sclerosis.

BACKGROUND: Systemic sclerosis (SSc) is a severe rheumatic disease of the interstitial tissue, in which heart and lung involvement can lead to disease-specific mortality. Our study tests the hypothesis that in addition to established prognostic factors, cardiopulmonary exercise testing (CPET) parameters, particularly peak oxygen uptake (peakVO2) and ventilation/carbon dioxide (VE/VCO2)-slope, can predict survival in patients with SSc. SUBJECTS AND METHODS: We retrospectively assessed 210 patients (80.9% female) in 6 centres over 10 years with pulmonary testing and CPET. Survival was analysed with Cox regression analysis (adjusted for age and gender) by age, comorbidity (Charlson-Index), body weight, body-mass index, extensive interstitial lung disease, pulmonary artery pressure (measured by echocardiography and invasively), and haemodynamic, pulmonary and CPET parameters. RESULTS: Five- and ten-year survival of SSc patients was 93.8 and 86.9%, respectively. There was no difference in survival between patients with diffuse (dcSSc) and limited cutaneous manifestation (lcSSc; p = 0.3). Pulmonary and CPET parameters were significantly impaired. Prognosis was worst for patients with pulmonary hypertension (p = 0.007), 6-min walking distance < 413 m (p = 0.003), peakVO2 < 15.6 mL∙kg- 1∙min- 1, and VE/VCO2-slope > 35. Age (hazard ratio HR = 1.23; 95% confidence interval CI: 1.14;1.41), VE/VCO2-slope (HR = 0.9; CI 0.82;0.98), diffusion capacity (Krogh factor, HR = 0.92; CI 0.86;0.98), forced vital capacity (FVC, HR = 0.91; CI 0.86;0.96), and peakVO2 (HR = 0.87; CI 0.81;0.94) were significantly linked to survival in multivariate analyses (Harrell's C = 0.95). This is the first large study with SSc patients that demonstrates the prognostic value of peakVO2 < 15.6 mL∙kg- 1∙min- 1 (< 64.5% of predicted peakVO2) and VE/VCO2-slope > 35.

Prognostic Relevance of Cardiopulmonary Exercise Testing for Patients with Chronic Thromboembolic Pulmonary Hypertension.

Background: Following acute pulmonary embolism (PE), a relevant number of patients experience decreased exercise capacity which can be associated with disturbed pulmonary perfusion. Cardiopulmonary exercise testing (CPET) shows several patterns typical for disturbed pulmonary perfusion. Research question: We aimed to examine whether CPET can also provide prognostic information in chronic thromboembolic pulmonary hypertension (CTEPH). Study Design and Methods: We performed a multicenter retrospective chart review in Germany between 2002 and 2020. Patients with CTEPH were included if they had ≥6 months of follow-up and complete CPET and hemodynamic data. Symptom-limited CPET was performed using a cycle ergometer (ramp or Jones protocol). The association of anthropometric data, comorbidities, symptoms, lung function, and echocardiographic, hemodynamic, and CPET parameters with survival was examined. Mortality prediction models were calculated by Cox regression with backward selection. Results: 345 patients (1532 person-years) were included; 138 underwent surgical treatment (pulmonary endarterectomy or balloon pulmonary angioplasty) and 207 received only non-surgical treatment. During follow-up (median 3.5 years), 78 patients died. The death rate per 1000 person-years was 24.9 and 74.2 in the surgical and non-surgical groups, respectively (p < 0.001). In age- and sex-adjusted Cox regression analyses, CPET parameters including peak oxygen uptake (VO2peak, reflecting cardiopulmonary exercise capacity) were prognostic in the non-surgical group but not in the surgical group. In mortality prediction models, age, sex, VO2peak (% predicted), and carbon monoxide transfer coefficient (% predicted) showed significant prognostic relevance in both the overall cohort and the non-surgical group. In the non-surgical group, Kaplan−Meier analysis showed that patients with VO2peak below 53.4% predicted (threshold identified by receiver operating characteristic analysis) had increased mortality (p = 0.007). Interpretation: The additional measurement of cardiopulmonary exercise capacity by CPET allows a more precise prognostic evaluation in patients with CTEPH. CPET might therefore be helpful for risk-adapted treatment of CTEPH.

[Spectrum of tuberculous diseases in a pulmonary outpatient clinic]. / Spektrum tuberkulöser Erkrankungen in der pneumologischen Praxis.

BACKGROUND: Although the incidence of 6.6 newly diagnosed tuberculosis (TB) cases per 100,000 inhabitants is in decline in Germany, TB remains a disease of significant epidemiologic importance. PATIENTS AND METHODS: From 04/2001 to 07/2008, a total of 75 TB patients of an internal-pulmonary outpatient clinic had been treated (0.5% of all patients). 58 (77.3%) patients fulfilled the criteria of an active TB, 17 (22.7%) of latent tuberculous infection (LTBI). 68.0% were male (average age men 39.3 +/- 16.9 years [mean +/- standard deviation], women 46.8 +/- 21.5 years; p = not significant). 69.3% of the patients were born in Germany, 30.7% abroad. 84.5% patients had isolated pulmonary, 8.6% additional organ involvement, and 6.9% isolated extrapulmonary TB. 62.1% of active TB cases were microbiologically proven (51.7% microscopically, 43.1% in addition culturally, 6.9% exclusively culturally, 19.0% by polymerase chain reaction [PCR]). RESULTS: Of 23 tests, 52.2% were fully sensitive against the most important first-line drugs ethambutol (M), isoniazid (H), rifampicin (R), pyrazinamide (Z), und streptomycin (S). 13.0% had an isolated resistance against H (4.4%) or S (8.6%), 4.4% a multiple drug resistance (MDR) against R und H, 30.4% a polyresistance (S and H). Symptoms were quite often unspecific, not taken care of, or misinterpreted. CONCLUSION: Diagnosis and therapy of an active or latent TB illness remains, an important task and challenge, necessitating an effective cooperation of outpatient, hospital, and health authority institutions.

Exercise and respiratory training improve exercise capacity and quality of life in patients with severe chronic pulmonary hypertension.

BACKGROUND: Pulmonary hypertension (PH) is associated with restricted physical capacity, limited quality of life, and a poor prognosis because of right heart failure. The present study is the first prospective randomized study to evaluate the effects of exercise and respiratory training in patients with severe symptomatic PH. METHODS AND RESULTS: Thirty patients with PH (21 women; mean age, 50+/-13 years; mean pulmonary artery pressure, 50+/-15 mm Hg; mean World Health Organization [WHO] class, 2.9+/-0.5; pulmonary arterial hypertension, n=23; chronic thromboembolic PH, n=7) on stable disease-targeted medication were randomly assigned to a control (n=15) and a primary training (n=15) group. Medication remained unchanged during the study period. Primary end points were the changes from baseline to week 15 in the distance walked in 6 minutes and in scores of the Short Form Health Survey quality-of-life questionnaire. Changes in WHO functional class, Borg scale, and parameters of echocardiography and gas exchange also were assessed. At week 15, patients in the primary and secondary training groups had an improved 6-minute walking distance; the mean difference between the control and the primary training group was 111 m (95% confidence interval, 65 to 139 m; P<0.001). Exercise training was well tolerated and improved scores of quality of life, WHO functional class, peak oxygen consumption, oxygen consumption at the anaerobic threshold, and achieved workload. Systolic pulmonary artery pressure values at rest did not change significantly after 15 weeks of exercise and respiratory training (from 61+/-18 to 54+/-18 mm Hg) within the training group. CONCLUSIONS: This study indicates that respiratory and physical training could be a promising adjunct to medical treatment in severe PH. The effects add to the beneficial results of modern medical treatment.

Inhaled iloprost for severe pulmonary hypertension.

BACKGROUND: Uncontrolled studies suggested that aerosolized iloprost, a stable analogue of prostacyclin, causes selective pulmonary vasodilatation and improves hemodynamics and exercise capacity in patients with pulmonary hypertension. METHODS: We compared repeated daily inhalations of 2.5 or 5.0 microg of iloprost (six or nine times per day; median inhaled dose, 30 microg per day) with inhalation of placebo. A total of 203 patients with selected forms of severe pulmonary arterial hypertension and chronic thromboembolic pulmonary hypertension (New York Heart Association [NYHA] functional class III or IV) were included. The primary end point was met if, after week 12, the NYHA class and distance walked in six minutes were improved by at least one class and at least 10 percent, respectively, in the absence of clinical deterioration according to predefined criteria and death. RESULTS: The combined clinical end point was met by 16.8 percent of the patients receiving iloprost, as compared with 4.9 percent of the patients receiving placebo (P=0.007). There were increases in the distance walked in six minutes of 36.4 m in the iloprost group as a whole (P=0.004) and of 58.8 m in the subgroup of patients with primary pulmonary hypertension. Overall, 4.0 percent of patients in the iloprost group (including one who died) and 13.7 percent of those in the placebo group (including four who died) did not complete the study (P=0.024); the most common reason for withdrawal was clinical deterioration. As compared with base-line values, hemodynamic values were significantly improved at 12 weeks when measured after iloprost inhalation (P<0.001), were largely unchanged when measured before iloprost inhalation, and were significantly worse in the placebo group. Further significant beneficial effects of iloprost treatment included an improvement in the NYHA class (P=0.03), dyspnea (P=0.015), and quality of life (P=0.026). Syncope occurred with similar frequency in the two groups but was more frequently rated as serious in the iloprost group, although this adverse effect was not associated with clinical deterioration. CONCLUSIONS: Inhaled iloprost is an effective therapy for patients with severe pulmonary hypertension.

Comparative evaluation of life cycle assessment models for solid waste management.

This publication compares a selection of six different models developed in Europe and America by research organisations, industry associations and governmental institutions. The comparison of the models reveals the variations in the results and the differences in the conclusions of an LCA study done with these models. The models are compared by modelling a specific case - the waste management system of Dresden, Germany - with each model and an in-detail comparison of the life cycle inventory results. Moreover, a life cycle impact assessment shows if the LCA results of each model allows for comparable and consecutive conclusions, which do not contradict the conclusions derived from the other models' results. Furthermore, the influence of different level of detail in the life cycle inventory of the life cycle assessment is demonstrated. The model comparison revealed that the variations in the LCA results calculated by the models for the case show high variations and are not negligible. In some cases the high variations in results lead to contradictory conclusions concerning the environmental performance of the waste management processes. The static, linear modelling approach chosen by all models analysed is inappropriate for reflecting actual conditions. Moreover, it was found that although the models' approach to LCA is comparable on a general level, the level of detail implemented in the software tools is very different.

Infected tibia defect fractures treated with the Masquelet technique.

The treatment after open and infected fractures with extensive soft tissue damage and bone deficit remains a challenging clinical problem. The technique described by Masquelet, using a temporary cement spacer to induce a membrane combined with reconstructive soft tissue coverage, is a possible solution. This study describes the work-up, operative procedure, complications, and the outcome of a homogenous group of patients with an open and infected tibia fracture and segmental bone loss treated with the Masquelet technique (MT).This retrospective study evaluates patients having sustained an open tibia fracture treated with the MT between 2008 and 2013 with a follow up of at least 1 year. The defect was either primary, caused by a high-grade open fracture or secondary due to a non-union after an open fracture. Prerequisite conditions prior to the procedure of the Masquelet were a defect zone with eradicated infection, an intact soft tissue cover and stability provided by an external fixation.Volume of the defect, time until the implantation of the spacer, time of the spacer in situ and the time to clinical and radiological union were evaluated. Patient records were screened for reoperations and complications. The functional clinical outcome was measured.Eight patients were treated with a follow up over 1 year. The spacer was implanted after a median of 11 (2-70) weeks after the accident. The predefined conditions for the Masquelet phase were reached after a median of 12 (7-34) operations.Seven patients required reconstructive soft tissue coverage. The volume of the defect had a median of 111 (53.9-621.6) cm, the spacer was in situ for a median of 12 (7-26) weeks. Radiological healing was achieved in 7 cases after a median time of 52 (26-93) weeks.Full weight bearing was achieved after a median time of 16 (11-24) weeks. Four patients needed a reoperation. The lower limb functional index was a median of 60% (32-92%).Seven out of 8 patients treated in this group of severe open and infected tibia fractures did both clinically and radiologically heal. Due to the massive destruction of the soft tissue, patients needed several reoperations with soft tissue debridements and reconstruction before the spacer and the bone graft could be implanted.

Deformation behavior of Re alloyed Mo thin films on flexible substrates: In situ fragmentation analysis supported by first-principles calculations.

A major obstacle in the utilization of Mo thin films in flexible electronics is their brittle fracture behavior. Within this study, alloying with Re is explored as a potential strategy to improve the resistance to fracture. The sputter-deposited Mo1-xRex films (with 0 ≤ x ≤ 0.31) were characterized in terms of structural and mechanical properties, residual stresses as well as electrical resistivity. Their deformation behavior was assessed by straining 50 nm thin films on polyimide substrates in uniaxial tension, while monitoring crack initiation and propagation in situ by optical microscopy and electrical resistance measurements. A significant toughness enhancement occurs with increasing Re content for all body-centered cubic solid solution films (x ≤ 0.23). However, at higher Re concentrations (x > 0.23) the positive effect of Re is inhibited due to the formation of dual-phase films with the additional close packed A15 Mo3Re phase. The mechanisms responsible for the observed toughness behavior are discussed based on experimental observations and electronic structure calculations. Re gives rise to both increased plasticity and bond strengthening in these Mo-Re solid solutions.

The SeqAn C++ template library for efficient sequence analysis: A resource for programmers.

BACKGROUND: The use of novel algorithmic techniques is pivotal to many important problems in life science. For example the sequencing of the human genome (Venter et al., 2001) would not have been possible without advanced assembly algorithms and the development of practical BWT based read mappers have been instrumental for NGS analysis. However, owing to the high speed of technological progress and the urgent need for bioinformatics tools, there was a widening gap between state-of-the-art algorithmic techniques and the actual algorithmic components of tools that are in widespread use. We previously addressed this by introducing the SeqAn library of efficient data types and algorithms in 2008 (Döring et al., 2008). RESULTS: The SeqAn library has matured considerably since its first publication 9 years ago. In this article we review its status as an established resource for programmers in the field of sequence analysis and its contributions to many analysis tools. CONCLUSIONS: We anticipate that SeqAn will continue to be a valuable resource, especially since it started to actively support various hardware acceleration techniques in a systematic manner.

Cardiopulmonary exercise testing for detecting pulmonary arterial hypertension in systemic sclerosis.

OBJECTIVES: Pulmonary arterial hypertension (PAH) is a devastating disease with limited survival and occurs as a frequent complication in patients with systemic sclerosis (SSc). A definite diagnosis of PAH is obtained by right heart catheterisation (RHC); however, the initial suspicion is raised by non-invasive methods. We assessed the diagnostic accuracy of key parameters derived from cardiopulmonary exercise testing (CPET) for detecting and ruling out SSc-associated PAH. METHODS: In a multicentre setting, we prospectively evaluated 173 consecutive patients with SSc without known PAH, but with clinical suspicion of PAH. Each patient underwent CPET and RHC. RESULTS: RHC identified PAH in 48 patients (27.8%), postcapillary pulmonary hypertension (PH) in 10 patients (5.8%) and ruled out PH in 115 patients (66.5%). CPET parameters correlated significantly with pulmonary haemodynamics. PeakVO2 and VE/VCO2 showed highest correlations with pulmonary arterial pressure, transpulmonary pressure gradient and pulmonary vascular resistance. Several parameters showed high sensitivity and specificity for PAH detection by receiver operating characteristic analysis. However, peakVO2 showed highest diagnostic accuracy (sensitivity 87.5%, specificity 74.8% at a threshold level of 13.8 mL/min/kg). A peakVO2 of >18.7 mL/kg/min was reached by 38/173 patients (22%) and excluded PAH in our cohort (negative predictive value 1.0). A nadir VE/VCO2 ratio of >45.5 showed a positive predictive value of 1.0. Diagnostic accuracy was highest in patients with low pulmonary arterial wedge pressure (<12 mm Hg). There were no study-related serious adverse events. CONCLUSIONS: CPET is a safe and valuable method in the non-invasive detection of SSc-associated PAH. It may be particularly beneficial for reducing unnecessary RHC procedures.

Reconstruction after talar fractures.

Malunited and nonunited talar fractures cause significant disability. Distinction between partial and total avascular necrosis (AVN) determines the choice of treatment. Patients who have minimal or no AVN and well-preserved joint cartilage may be amenable to corrective osteotomy through the malunited fracture or removal of the pseudoarthrosis. Secondary reconstruction with joint preservation leads to considerable functional improvement in painful talar malunions and nonunions in reliable patients. If symptomatic arthritis is present, arthrodeses and correction of deformity through the fusion or with additional osteotomies provide predictable results, although they do not restore normal foot function. Fusions should be limited to the affected joint. If the subtalar joint shows severe arthritic changes, every attempt should be made to salvage the ankle and talonavicular joints.

[Severe acute respiratory syndrome (SARS)]. / Schweres akutes respiratorisches Syndrom (SARS).

The sudden appearance of the severe acute respiratory syndrome (SARS) in 2003 demonstrated to the world at large that despite the high standard of medical care in affected countries, a highly contagious emerging infectious disease could spread rapidly worldwide. By application and improvement of stringent infection control measures, a further spread of SARS could be stopped and the disease could so far be defeated. In the meantime, decisive progress in the knowledge about the structure and further characteristics of the SARS coronavirus (SARS-CoV) have been made, including the likely virus reservoir and the ways of spread. Validated diagnostic tests are now available and are further being improved. Effective vaccines and antiviral agents are being developed. Of imminent importance to prepare against a resurgence of SARS, remain, besides an exact knowledge about the viral pathogen and its possible further behavior, constant vigilance, early recognition, and instant isolation of suspected cases of SARS.

Assessment of survival in patients with primary pulmonary hypertension: importance of cardiopulmonary exercise testing.

BACKGROUND: Primary pulmonary hypertension (PPH) is a life-threatening disease. Prognostic assessment is an important factor in determining medical treatment and lung transplantation. Whether cardiopulmonary exercise testing data predict survival has not been reported previously. METHODS AND RESULTS: We studied 86 patients with PPH (58 female, age 46+/-2 years, median NYHA class III) between 1996 and 2001 who were followed up in a tertiary referral center. Right heart catheterization was performed and serum uric acid levels were measured in all patients. Seventy patients were able to undergo exercise testing. At the start of the study, the average pulmonary artery pressure was 60+/-2 mm Hg, average pulmonary vascular resistance was 1664+/-81 dyne x s x cm(-5), average serum uric acid level was 7.5+/-0.35 mg/dL, and average peak oxygen uptake during exercise (peak VO(2) was 11.2+/-0.5 mL x kg(-1) x min(-1). During follow-up (mean: 567+/-48 days), 28 patients died and 16 underwent lung transplantation (1-year cumulative event-free survival: 68%; 95% CI 58 to 78). The strongest predictors of impaired survival were low peak VO(2) (P<0.0001) and low systolic blood pressure at peak exercise (peak SBP; P<0.0001). In a multivariable analysis, serum uric acid levels (all P<0.005) and diastolic blood pressure at peak exercise independently predicted survival (P<0.05). Patients with peak VO(2) < or =10.4 mL x kg(-1) x min(-1) and peak SBP < or =120 mm Hg (ie, 2 risk factors) had poor survival rates at 12 months (23%), whereas patients with 1 or none of these risk factors had better survival rates (79% and 97%, respectively). CONCLUSIONS: Peak VO(2) and peak SBP are independent and strong predictors of survival in PPH patients. Hemodynamic parameters, although also accurate predictors, provide no independent prognostic information.

Primary pulmonary hypertension may be a heterogeneous disease with a second locus on chromosome 2q31.

OBJECTIVES: The aim of our study was to identify genetic causes of primary pulmonary hypertension (PPH), to estimate the proportion of families with mutations in the BMPR2 (bone morphogenetic protein receptor type 2) gene, and to examine whether genetic heterogeneity might play a role. BACKGROUND: The BMPR2 mutations have been identified in a substantial portion of patients with familial or sporadic PPH. However, the genetic cause of PPH remains unclear in at least 45% of families. METHODS: We investigated 130 members of 10 families with at least 1 PPH patient, recruited without selection for familial disease. Manifest PPH was documented in 21 individuals. An increase in pulmonary artery systolic pressure (PASP) above 40 mm Hg during supine bicycle exercise was found in 46 healthy individuals. Their PASP increased from 21.0 +/- 4.6 mm Hg at rest to 54.0 +/- 9.8 mm Hg during exercise. In 51 relatives, PASP values were normal at rest and during exercise, and 12 members were classified as status unknown. RESULTS: Two families showed a mutation in the BMPR2 gene. Three families with no BMBR2 mutation showed evidence for linkage to a more proximal location on chromosome 2q31 (odds ratio [OR] for linkage 1.1.10(6):1). This locus, designated PPH2, maps in-between the markers D2S335 and D2S2314. We obtained significant support for heterogeneity in PPH with an OR of 2.8.10(11). CONCLUSIONS: We conclude that PPH may be a genetically heterogeneous disorder with at least two-and possibly more-causative genes.

Bosentan improves exercise tolerance and Tei index in patients with pulmonary hypertension and prostanoid therapy.

STUDY OBJECTIVE: Pulmonary arterial hypertension (PAH) is a progressive disease with a bad prognosis. Prostanoids are well established in the medical treatment of this disease. Treatment of patients with progressive disease despite prostanoids remains a therapeutic challenge. In this study, we examined the effect of adding bosentan, an endothelin antagonist, to existing prostanoid therapy on exercise capacity (6-min walking distance [6MWD]) and right ventricular (RV) function (Tei index) in patients with progressive pulmonary hypertension. DESIGN: Prospective, nonrandomized, open-label study. SETTING: University hospital. PATIENTS: Sixteen patients with pulmonary hypertension (PAH, n = 10; pulmonary hypertension due to other cause, n = 6) with progressive disease receiving either beraprost (n = 3), inhaled iloprost (n = 10), or iloprost IV (n = 3). INTERVENTIONS: Combination therapy with bosentan (final dosage, 125 mg bid) was initiated following an interval of 3-months minimum of unchanged prostanoid therapy. MEASUREMENTS AND RESULTS: Tei index, 6MWD, and New York Heart Association (NYHA) functional class were assessed prior to the initiation of combination therapy (baseline), at 6 months after initiation of combination therapy, and every 3 months thereafter. Two patients were followed up for 6 months only; all remaining patients reached a mean follow-up period (+/- SD) of 13.5 +/- 5.0 months (range, 9 to 22 months). 6MWD increased by 42.5 +/- 66 m at 6 months and 44.6 +/- 66 m at the last follow-up (both time points vs baseline, p < 0.001), and Tei index improved by -0.13 +/- 0.08 at 6 months and - 0.13 +/- 0.11 at the last follow-up (both time points vs baseline, p < 0.001). All patients reported subjective improvements. Nine of 16 patients exhibited improvement in NYHA functional class at 6 months. No side effects occurred that required dose adjustment or discontinuation of the study medication. CONCLUSION: Bosentan administered to patients with progressive pulmonary hypertension receiving prostanoids resulted in an increased exercise capacity and an improved RV function. Bosentan therefore appears to be well suited for combination therapy with prostanoids in selected patients pending results of ongoing randomized trials.