[Diagnosis of thoracic outlet syndrome by angio-MRI].

Objective: To evaluate the sequences and maneuvers recommended for the study of the thoracic outlet syndrome (TOS) and the usefulness of magnetic resonance imaging (MRI) in demonstrating its etiology.

Material And Methods: We present a study of eight patients with clinical presentation suggestive of TOS. All underwent MRI, gadolinium-enhanced angio-MRI with the arms extended along the body and with postural maneuvers of abduction and elevation of the arms, plain-film chest x-rays, and digital angiography.

Detection of human immunodeficiency virus type 1 by PCR before seroconversion in high-risk individuals who remain seronegative for prolonged periods.

HIV-1 seronegative patients at high risk for HIV infection were followed up. In 1990 PCR was positive for HIV DNA sequences in samples of 17 seronegative patients who continued to report for surveillance of HIV infection. There was clear evidence of seroconversion in four of these 17 seronegative patients, while in one patient an indeterminate result for HIV was repeatedly obtained in different samples.

Detection of hepatitis B virus DNA and determination of surface antigen expression in peripheral blood mononuclear cells from patients with AIDS.

The polymerase chain reaction (PCR) was used to analyze the presence of hepatitis B virus (HBV) DNA in serum and peripheral blood mononuclear cells (PBMCs) from 20 patients with AIDS with and without conventional HBV serological markers. DNA sequences of HBV were detected in PBMCs from 13 patients, nine of whom were positive for anti-HBc only and four of whom were also positive for anti-HBs. When PBMCs from patients were activated in culture with phytohemagglutinin, the presence of HBsAg could be detected in the culture supernatants from four of 13 patients with HBV DNA in their PBMCs; for two of the four, HBV DNA could also be detected in the culture supernatant after DNA amplification.