40-Gbit/s all-optical circulating shift register with an inverter.

We report what is believed to be the first demonstration of an all-optical circulating shift register using an ultrafast nonlinear interferometer with a polarization-insensitive semiconductor optical amplifier as the nonlinear switching element. The device operates at 40 Gbits/s, to our knowledge the highest speed demonstrated to date. Also, the demonstration proves the cascadability of the ultrafast nonlinear interferometric switch.

Usefulness of transesophageal echocardiography in the pediatric catheterization laboratory.

Transesophageal echocardiography was performed in 51 children (aged 2 to 14 years, mean 4; weight 9 to 50 kg, mean 21) undergoing elective diagnostic or therapeutic cardiac catheterization. The interventional procedures were percutaneous balloon dilation of pulmonary (n = 8) and aortic (n = 2) valve stenosis, percutaneous closure of patent ductus arteriosus (n = 8), and attempted occlusion of Pott's anastomosis by the double umbrella device (n = 1). The diagnostic catheterizations were performed on preoperative children of whom 5 had undergone previous palliative procedures. Precise placement of the balloon across the valve, timing of balloon inflation and deflation according to real-time monitoring of ventricular function and immediate evaluation of results and complications were accomplished with transesophageal monitoring. The exact position of distal and proximal umbrellas of patent ductus occlusive devices was checked on transesophageal imaging and completeness of occlusion controlled on color Doppler. The only relevant information in the preoperative cases was the detection of a septic thrombus in a severely ill patient. With more experience and smaller probes, transesophageal echocardiography may become a new method of monitoring cardiac catheterization also in smaller children where it may reduce duration of the procedure and amount of contrast material.

Late left atrioventricular valve insufficiency after repair of partial atrioventricular septal defects: anatomical and surgical determinants.

Risk factors for late left atrioventricular (AV) valve insufficiency, which occurred in 16 (18%) of 90 patients evaluated after repair of partial AV septal defect, were examined. The operative findings in 9 patients undergoing reoperation were also examined. Preoperative left AV valve insufficiency was significantly more common in the group with late left AV valve incompetence, as were associated valvular malformations as a whole and fenestrations of valve leaflets in particular. Conversely, the higher incidence of malformed or malpositioned papillary muscles, accessory clefts, and double-orifice left AV valves in the group with late left AV valve insufficiency did not reach significance. The method of surgical treatment of the septal commissure was not a significant factor. In the group having reoperation, additional valvular malformations were found in association with inappropriate treatment of the septal commissure in 7 patients. The 2 remaining patients had either a directly sutured ostium primum or dilatation of the annulus. Three re-repairs were successful. Five patients required prosthetic valve replacement. Preoperative left AV valve insufficiency and associated valvular malformations are major determinants of late left AV valve insufficiency in partial AV septal defect.

[Congenital coronary fistulae. Comments on 9 surgical cases]. / Fistole coronariche congenite. Considerazioni su 9 casi operati.

The authors relate their experience concerning the surgical correction of congenital coronary fistula. Between May 1971 and June 1986, 9 patients (4 boys and 5 girls) aged from 17 days to 49 years were operated upon at the Division of Cardiac Surgery of Bergamo (Ospedali Riuniti). All the patients, except three who were asymptomatic, showed early cardiac failure or dyspnoea on effort and angina in the elderly. At the physical examination a continuous murmur was heard in 8 cases; the chest x-ray showed significant cardiomegaly and on the electrocardiogram a right/left ventricular hypertrophy pattern was detected in 5 patients. All the patients underwent cardiac catheterization and a coronary angiography. The left-to-right shunt ranged from 60% to 250% of the cardiac output. The anomalous communication affected the right coronary artery in 7 cases and the left in 2, opening into the right atrium in 4 patients, into the right ventricle in 3 and into the pulmonary artery in 2. All patients but one, in whom division and suture were the only necessary procedures, underwent correction by means conventional cardiopulmonary by-pass with moderate hypothermia. In 3 cases closure through the coronary artery was preferred, in 1 through the right ventricle and in 2 transpulmonary. There was only 1 late death which occurred in a 3 year-old patient due to renal failure. After a mean follow-up of 6 years, 7 patients are to be asymptomatic while 1 patient had to be reoperated for a significant residual shunt.

Characterization of human T lymphocyte subpopulations (TG and T non G): cytologic examination and cytographic analysis.

Two T lymphocyte subpopulations were separated with an immunological method. In fact recently two T cell subsets with receptors for the Fc of IgM (TM) and of IgG (TG) respectively have been described. We have specifically separated TG and T non G lymphocytes by the rosetting technique. Cytological examination was performed on the two cell fractions: the results are in agreement with that already reported. Cytographic analysis was also carried out confirming the cytologic results. The possible practical implications of these acquisitions and those already applied are discussed.

Antilymphocyte antibodies in rheumatoid arthritis.

The presence of cold and non-cold reacting antilymphocyte antibodies of IgG class, active against allogeneic T lymphocytes deprived of Fcgamma receptor bearing cells, was investigated by indirect immunofluorescence (IF) and by microlymphocytotoxicity in 50 patients with Rheumatoid Arthritis (RA). 6/50 rheumatoid sera have shown the presence of anti-T-lymphocyte antibodies against 8/50 positivities found when the whole lymphocyte population was employed as the target in IF test. The positive sera were also examined by microlymphocytotoxicity test and the correlation with the number of lymphoid cells in peripheral blood was studied. In only one case (RA + Sjögren's syndrome) a positive IF test, in vitro cytotoxicity and in vivo lymphopenia were observed. In the other IF positive cases neither lymphopenia in vivo nor lymphocytotoxicity of the sera were observed; these results can be due to either the presence of cold or not complement fixing antilymphocyte antibodies.