Scleroderma: The Need for Extreme Remedies

Assessment for Pulmonary Artery Hypertension Using Clinical and Echocardiographic Criteria in Patients With Systemic Sclerosis

BACKGROUND

Prognosis of systemic sclerosis (SSc) is affected by pulmonary artery hypertension (PAH).

METHODS

Among 202 patients (mean age: 46.1 ± 13.3 years; 177 women) with SSc, those with a tricuspid regurgitation (TR) jet maximal velocity at 2D-echocardiography (2DE) < 2.8m/second were not considered at high risk for PAH, whereas those with a TR velocity >3m/second or between 2.8 and 3m/second and associated with dyspnea were.

RESULTS

Among 22 patients at risk, 15 (mean age: 50.4 ± 14.3 years) had definite precapillary PAH on right heart catheterization (RHC). The delay period between recognitions of SSc and PAH was 12.9 ± 5.2 years. Dyspnea was present in all 15 patients, 11 (73.3%) being in the New York Heart Association class III or IV. The 2DE showed normal left ventricular geometrics and function (n = 15), enlargement of the right-sided cardiac chambers (n = 12), increased pulmonary arterial resistances with a TR velocity to pulmonary time-velocity integral ratio of > 0.2 (n = 15) and impaired right ventricle function (n = 15). RHC showed severe PAH in all 15 patients (mean pulmonary artery pressure: 48 ± 17mmHg and mean right atrial pressure: 11.8 ± 4.4mmHg) and a reduced cardiac index (2.2L/m²). There was no statistical difference between patients with and without PAH regarding age, sex ratio, duration from onset of disease, diffuse or cutaneous limited type of SSc, Rodnan severity score and presence of digital ulcerations or autoantibodies. Telangiectasia (P = 0.01) and New York Heart Association class III or IV heart failure (P = 0.001) were more frequent in patients with PAH.

CONCLUSION

A combined clinical and Doppler-coupled 2DE screening of PAH risk in patients with SSc is useful to select those who can undergo RHC.

Biokinetic Mechanisms Linked With Musculoskeletal Health Disparities: Stochastic Models Applying Tikhonov's Theorem to Biomolecule Homeostasis

Multiscale technology and advanced mathematical models have been developed to control and characterize physicochemical interactions, respectively, enhancing cellular and molecular engineering progress. Ongoing tissue engineering development studies have provided experimental input for biokinetic models examining the influence of static or dynamic mechanical stimuli (Saha, A. K., and Kohles, S. S., 2010, "A Distinct Catabolic to Anabolic Threshold Due to Single-Cell Nanomechanical Stimulation in a Cartilage Biokinetics Model," J. Nanotechnol. Eng. Med., 1(3) p. 031005; 2010, "Periodic Nanomechanical Stimulation in a Biokinetics Model Identifying Anabolic and Catabolic Pathways Associated With Cartilage Matrix Homeostasis," J. Nanotechnol. Eng. Med., 1(4), p. 041001). In the current study, molecular regulatory thresholds associated with specific disease disparities are further examined through applications of stochastic mechanical stimuli. The results indicate that chondrocyte bioregulation initiates the catabolic pathway as a secondary response to control anabolic processes. In addition, high magnitude loading produced as a result of stochastic input creates a destabilized balance in homeostasis. This latter modeled result may be reflective of an injurious state or disease progression. These mathematical constructs provide a framework for single-cell mechanotransduction and may characterize transitions between healthy and disease states.