Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0019621 (Langerhans cell histiocytosis)
 3,250 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Pulmonary hypertension is a pathophysiologic condition characterized by the increase of mean pulmonary arterial pressure > or =25 mmHg. A concomitant increase of pulmonary wedge pressure >15 mmHg may be present (post-capillary pulmonary hypertension) or not (precapillary pulmonary hypertension). The increase of pulmonary arterial pressure and of pulmonary vascular resistance and consequent elevation of the right ventricular afterload lead to right ventricular failure after variable periods of time. Pulmonary hypertension is present in multiple clinical conditions which have been classified in five groups. Pulmonary arterial hypertension (group 1) includes the familial and the idiopathic form and the forms associated with anorexigen drug use, connective tissue diseases, congenital heart diseases, HIV infection and portal hypertension. Group 2 includes all left heart diseases characterized by the increase of left atrial pressure and pulmonary wedge pressure (post-capillary pulmonary hypertension). Group 3 includes parenchymal lung diseases (chronic obstructive lung disease, lung fibrosis, ecc). Chronic thromboembolic pulmonary hypertension (group 4) is characterized by the obstruction of elastic pulmonary arteries at different levels by organized thromboembolism. Group 5 includes heterogeneous conditions such as sarcoidosis and histiocytosis X. These clinical groups are characterized by different pathobiologic and pathophysiologic mechanisms and therapeutic strategies. The exact pathobiologic mechanisms leading to pulmonary arterial hypertension (group 1) are unknown. Genetic factors (inheritable forms), predisposing factors (female gender) and exogenous factors (drugs, antibodies, viruses, congenital heart disease, etc). Endothelial dysfunction of lung microcirculation is invariably present and is characterized by the reduction of vasodilator and antiproliferative substances (prostacyclin, nitric oxide) and by the increase of vasoconstrictor and mitogenic factors (endothelin, thromboxane A2). Current approved therapies are targeted to the correction of this imbalance, which leads to the progressive increase of pulmonary vascular resistance. Different therapeutic strategies that are effective in diverse groups require an appropriate diagnostic algorithm in order to identify the precise group and specific conditions within the group. Evaluation of vasoreactivity and assessment of the severity of functional and hemodynamic changes are also required in pulmonary arterial hypertension for an appropriate therapeutic decision-making and estimate of results.
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PMID:[Pulmonary arterial hypertension. Part I: pathobiologic, pathophysiologic, clinical and diagnostic aspects]. 1953 40

Pulmonary arterial hypertension (PAH) secondary to pulmonary Langerhans cell histiocytosis (PLCH) is known to be a relatively common complication and is associated with a poor prognosis. However, the optimal therapeutic approach for these cases remains to be established. A 57-year-old man visited our hospital because of a progressive dry cough. A thoracic computed tomography examination showed a combination of diffuse thick-walled cysts and reticulonodular shadows that were predominant in bilateral upper lobes of the lungs. He was diagnosed as having PLCH based on the results of video-assisted thoracoscopic lung biopsies. During a 3-year clinical course, his condition deteriorated despite smoking cessation. A systemic evaluation demonstrated precapillary PAH caused by PLCH (PAH-PLCH), and treatment with tadalafil, a phosphodiesterase-5 inhibitor, was started. During a 50-month period of treatment with tadalafil, improvements in his dyspnea, 6-min walking distance, and hemodynamics were maintained without either overt hypoxemia or pulmonary edema. We considered that tadalafil therapy may be a useful option in the treatment of patients with PAH-PLCH.
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PMID:Long-term improvement during tadalafil therapy in a patient with pulmonary hypertension secondary to pulmonary Langerhans cell histiocytosis. 2733 Sep 52