An efficient solid-phase strategy for the construction of chemokines.

Synthesis of chemokines via stepwise SPPS approaches has been shown to be a challenge. Herein, a complete study of different coupling methods, solvents and temperature combined with a continuous-flow synthesizer equipped with feedback monitoring was carried out. The results from this study indicate that this family of molecules can be prepared using an Fmoc/Bu(t) chemical approach and provide a general method to apply for the elongation of other difficult sequences.

Evaluation of normal prosthetic valve function by Doppler echocardiography.

Previous investigations have suggested that Doppler echocardiography is useful in detecting dysfunction in aortic (AVR) and mitral prostheses (MVR). However, to diagnose abnormalities, the spectrum of normal velocities through these valves must be established. Therefore, we used Doppler echocardiography to study 100 patients with 105 prosthetic valves that had no clinical evidence of valve dysfunction 9 +/- 8 days postoperatively. There were 66 Carpentier-Edwards (C-E), 23 St. Jude (S-J), and 16 Ionescu-Shiley (I-S) valves. In 70 AVR, the peak instantaneous gradient was 26.4 +/- 8.2 Hg, mean systolic gradient was 15.6 +/- 5 mm Hg, and gradients varied inversely with valve size, although differences were significant only when comparing the smallest vs the largest valve sizes (p less than or equal to 0.03). Peak instantaneous gradients greater than 36 mm Hg occurred only in AVR size 23 or smaller. There were no significant differences in gradients among C-E, S-J, and I-S AVR. In 35 MVR, mean gradient was 6.9 +/- 2.3 mm Hg and valve area was 2.7 +/- 0.8 cm2; neither varied significantly with valve size. However, S-J MVR group had smaller mean gradients and larger effective valve area than C-E bioprosthetic MVR (p = 0.01 and p = 0.05, respectively). Regurgitation was more common in AVR (26%) than in MVR (9%), p = 0.04, although all instances were mild and clinically silent. We conclude that normal AVR and MVR of a given size and type have a predictable range of Doppler echocardiographic parameters. Doppler evidence of mild regurgitation is a frequent finding in normal AVR and MVR.(ABSTRACT TRUNCATED AT 250 WORDS)

Echocardiographic findings in 25 patients with left atrial myxoma.

The echocardiographic findings were studied in 25 patients with pathologically proved left atrial myxoma. All patients had M-mode echocardiograms and 14 had two-dimensional studies. Seventeen patients had pre- and postoperative echocardiograms. Clinical, hemodynamic, angiographic and pathologic correlations were made. The diagnosis of left atrial myxoma was suspected clinically in only three patients before the echocardiographic study. The correct echocardiographic diagnosis was made in 24 patients; in one patient it was missed with an M-mode study. In addition to the usual "mass" of extraneous echoes seen behind the mitral valve in the left atrium, the only other consistent abnormality on M-mode study was a decreased EF slope of the mitral valve (3.9 +/- 3.5 cm/s). The following dimensions were usually normal: left atrium, 4.0 +/- 0.7 cm; right ventricle, 2 +/- 0.7 cm; left ventricular end-diastolic diameter, 4.8 +/- 0.6 cm and end-systolic diameter, 2.9 +/- 0.5 cm. The mean percent of shortening was 37 +/- 5%. Two-dimensional echocardiography correctly identified the presence of a left atrial myxoma in all 14 patients studied. It provided additional information regarding size, shape, mobility, surface characteristics and site of insertion of the tumor. Eighteen patients had hemodynamic and angiographic studies. Coronary artery disease was found in one patient with typical angina. Echocardiography is an excellent technique for visualizing atrial myxoma. Cardiac catheterization is probably not needed before excision of a myxoma.