GATA5 loss-of-function mutations associated with congenital bicuspid aortic valve.

Bicuspid aortic valve (BAV) is the most common form of congenital cardiovascular defect in humans worldwide and is responsible for substantial morbidity and mortality. Accumulating evidence has demonstated that genetic risk factors are involved in the pathogenesis of BAV. However, BAV is genetically heterogeneous and the genetic basis underlying BAV in a large number of patients remains unknown. In the present study, the coding regions and splice junction sites of the GATA5 gene, which codes for a zinc-finger transcription factor crucial for the normal development of the aortic valve, was sequenced initially in 110 unrelated patients with BAV. The available relatives of the mutation carriers and 200 unrelated healthy individuals used as controls were subsequently genotyped for GATA5. The functional effect of the mutations was characterized by using a luciferase reporter assay system. As a result, two novel heterozygous GATA5 mutations, p.Y16D and p.T252P, were identified in two families with autosomal dominant inheritance of BAV, respectively. The variations were absent in 400 control chromosomes and the altered amino acids were completely conserved evolutionarily. Functional assays revealed that the two GATA5 mutants were associated with significantly reduced transcriptional activity compared with their wild-type counterpart. To the best of our knowledge, this is the first study on the association of GATA5 loss-of-function mutations with enhanced susceptibility to BAV, providing novel insight into the molecular mechanism involved in human BAV and suggesting a potential role for the early prophylaxis and personalized treatment of this common congenital heart disease.

[The ultrastructural features of sputum deposition and its value in the diagnosis of pulmonary alveolar proteinosis].

OBJECTIVE: To investigate the ultrastructural features of sputum deposition (SD) and its value in the diagnosis of pulmonary alveolar proteinosis (PAP). METHODS: Seven patients with PAP diagnosed by lung biopsy and cytology were enrolled in this study. The patients consisted of 5 men and 2 women, whose median age was 48 years (range 36 to 73). SD and bronchoalveolar lavage fluid (BALF) sediment were made into ultrathin sections and observed under transmission electron microscope (TEM), respectively. Seven cases of control group composed of 4 men and 3 women whose median age was 49 years (range 39 to 68) including 3 cases of bacterial pneumonia, two cases of COPD and 2 cases of exudative pulmonary tuberculosis. Each SD was made into ultrathin section, and compared with the experimental group. RESULTS: In PAP group, Periodic acid-schiff (PAS) staining was performed on 7 sputum smears and none of them was tested positive for any components with diagnostic interest. Four cases from the 7 paraffin-embed sections of BALF sediment by microscopic examination suggested PAP. Under TEM, BALF sediment showed that many lamellar bodies existed in and outside alveolar epithelial cells, and 5 specimens were consistent with PAP diagnosis. Compared with BALF sediment, SD had apparent degeneration with more myelin phagosomes in the cytoplasm of macrophages, more lamellar bodies in alveolar epithelial cells, and lots of lamellar bodies in the shape of concentric circle in the extracellular spaces. Four from the 7 SD samples were consistent with the diagnosis of PAP. No significant difference was found between SD and BALF in the diagnosis of PAP by electronic examination (P > 0.05). In the 7 cases of control group no drifting osmiophilic lamellar bodies in extracellular space were detected. CONCLUSIONS: The osmiophilic lamellar bodies with diagnostic value were found in SD and BALF of patients with PAP. TEM of SD in combination with clinical manifestations and radiologic findings can make a definitive diagnosis of PAP, especially for those patients who have contraindications to lung biopsy and lung lavage.

[Ultrasound surveillance of cervical lymph node metastasis in thoracic esophageal carcinoma].

OBJECTIVE: To improve the accuracy of preoperative evaluation of cervical lymph node metastasis in thoracic esophageal squamous carcinoma. METHODS: Forty-two patients with thoracic esophageal squamous carcinoma underwent neck ultrasonography. Enlarged lymph nodes with their long axis greater than 10 mm and a short-to-long axis ratio greater than 0.5 were considered as metastatic. RESULTS: Preoperative neck ultrasonography revealed the enlarged lymph nodes in 16 patients, but only in 5 (31%) cases the nodes were palpable. Among them 9 were classified as metastatic (cM(1-LN)), including 4 patients with palpable nodes. In 5 cM(1-LN) patients surgical intervention was canceled and the remaining 37 patients underwent trans-thoracic esophagectomy. Cervical node metastasis (pM(1-LN)) was confirmed pathologically in 6 surgical patients, 4 with tumors invading the adventitia (pT3) and the other 2 into the surrounding structure (pT(4)) (pT(1), pT(2) vs. pT(3), pT(4), P = 0.020). All 6 pM(1-LN) patients had concomitant mediastinal node metastasis and 4 of them had upper abdominal node metastasis. Statistically significant relationship was detected between cervical and abdominal nodal status (r = 0.536, P = 0.007). In comparison with the results of pathological examination and treatment response, the accuracy and sensitivity were 81% and 95% (P = 0.043), 36% and 82% (P = 0.081), respectively, for palpation and ultrasonography. Five out of 39 (13%) patients had their therapy changed due to ultrasonographic findings. CONCLUSIONS: Neck ultrasonography for cervical lymphadenopathy is of high sensitivity and accuracy, which plays an important role in the preoperative evaluation and therapeutic decision-making.