Advances in imaging of lymph flow disorders.

Conventional oil-contrast lymphography has long been the mainstay for lymphatic imaging. However, the emergence of computed tomography (CT) and magnetic resonance (MR) imaging has severely curtailed its use. Because of recent improvements and refinements, lymphangioscintigraphy now permits high-resolution imaging of peripheral lymphatic vessels and provides insight into lymph flow dynamics. It is indispensable for patients with known or suspected lymphatic circulatory disorders in confirming the diagnosis and delineating the pathogenesis and evolution of lymphedema. In addition, lymphangioscintigraphy helps evaluate lymphatic truncal anatomy and radiotracer transport. It can also be used to evaluate the efficacy of various treatment options designed to facilitate lymph flow or reduce lymph formation. The procedure is essentially noninvasive, can easily be repeated, and does not adversely affect the lymphatic vascular endothelium. MR imaging complements lymphangioscintigraphy in the monitoring and treatment of more complex lymphatic circulatory disorders, whereas CT facilitates catheter-guided percutaneous sclerosis or obliteration of specific lymphangiectasia or lymphangioma syndromes. Ultrasonography has proved useful in the setting of filariasis. Patients with a provisional diagnosis of peripheral lymphatic dysfunction or idiopathic edema should undergo diagnostic lymphangioscintigraphy and, in some cases, MR imaging to verify diagnostic accuracy, pinpoint the specific abnormality, and help guide subsequent therapy.

Influence of the level of dietary ethanol in mice with murine AIDS on resistance to Streptococcus pneumoniae.

Chronic ethanol consumption impairs cellular immune functions. This may explain the increased occurrence of various opportunistic infections in heavy ethanol users. Immunological alterations associated with Acquired Immune Deficiency Syndrome (AIDS) also permit more opportunistic infections. In this study, we used a murine model of retrovirus infection induced by LP-BM5 murine leukemia virus. The combined effects of ethanol use and early retroviral infection (prior to the development of AIDS) on resistance to Streptococcus pneumoniae were investigated. Consumption of ethanol by non-retrovirus-infected mice resulted in decreased resistance to S. pneumoniae. However, retrovirus-infected mice fed a diet containing high concentrations of ethanol (6 and 7% v/v) exhibited a greater resistance to S. pneumoniae infection than retrovirus-infected mice fed diets with lower concentrations (5%) or no ethanol. The total number of white blood cells also decreased as serum ethanol levels increased. There were also fewer lymphocytes and more neutrophils and monocytes in retrovirus-infected mice fed ethanol. Diet consumption decreased as the concentration of ethanol increased in the diet. Consumption was dependent upon the dark-light cycle. The highest diet consumption was observed during the first 4 hr of the dark period. The level of ethanol in serum was influenced by the amount of the diet consumed and its ethanol concentration. Both retrovirus infection and ethanol consumption effected survival after S. pneumoniae infection.