Sclerosis Category

There is substantial evidence that the endothelium is damaged early in the course of SSc. Increased levels of von Willebrand’s factor antigen, considered indicative of endothelial injury, are found early in the course of the illness. However, it is likely that functional endothelial impairment begins prior to this change, with impaired venous responsiveness to substance […]

Comparison of the response to substance P in normal subjects and in those with SSc revealed that both groups achieved a significant fall in SVR, although the magnitude of the fall was far greater in normal individuals. In control subjects, this was accompanied by a 32% rise in SI and an increase in skin temperature suggesting cutaneous […]

Responsiveness of the pulmonary vasculature to vasodilators is commonly assessed in patients with PHT to obtain prognostic information and to guide treatment. An increase in SI signifying a decrease in PVR was seen with adenosine infusion in SSc subjects with PHT. Similar responses have been seen in this patient group in response to other vasodilator […]

Results of Substance P Infusion Skin temperature rose in all subjects during substance P infusion (p<0.05 in all groups); the magnitude of the rise was greater than 1°C in all but two subjects (one normal control subject, one SSc-PHT). Arterial oxygen saturation did not fall below 90% during the infusion in any subject. Responses to […]

Patients with SSc-PHT had a lower effective pulmonary capillary blood flow and higher SVR than those with SSc alone. SI also tended to be lower in the SSc-PHT groups (19.6±3.6 mL/m2 for SSc-PHT vs 25.5±5.1 mL/m2 for SSC; p>0.05) compared to normal control subjects (38.9 ±7.2; p<0.05 compared with both SSc groups). Patients with SSc-PHT had estimated […]

Substance P and adenosine were infused continuously at rising concentrations over 50 and 40 min, respectively (dose increase every 10 min), and all parameters were measured every 5 min. The final result for a given vasodilator dose was taken as the average of the two sets of parameters measured during that dose interval. Infusions were […]

Effective pulmonary capillary blood flow, equal to cardiac output minus right-to-left shunt, was estimated using argon and freon rebreathing. Measurements were performed with the subjects at rest in a semirecumbent position. A standard anesthetic bag connected to a three-way rebreathing valve (3900C; Hans-Rudolph; Kansas City, KS) was filled with a volume of the test gas […]