No abstract

There is constant recirculation of the small lymphocytes from the blood into the lymphatic tissues. The most important route of recirculation is the postcapillary venule (1-5). The small lymphocytes which enter the lymph node from the bloodstream are necessary for the immune response (6 8). Furthermore, it has been suggested that the microcirculation in the lymph node plays a role in antigen uptake (9) and in propagation of the immune response (10). The information concerning cellular interchange between the blood and lymphatic tissues was based on tracer studies, radioautographic examination, and electron microscopy.In spite of the substantial recent information, our knowledge concerning the role of the blood circulation in the immune response is fragmented, and a more comprehensive morphological evaluation of the microvasculature still seems necessary.This investigation was designed to determine the alterations of the microvascular morphology during the course of the p r i m a r y i m m u n e response. T h e evaluation was based on microangiograms and histologic sections. Microangiography is a highly suitable m e t h o d for a detailed study of the microvasculature (11). I t permits an accurate, three-dimensional reconstruction of the capillary and postcapillary structures and can be correlated with the histologic findings. Materials and MethodsThe animal model utilized in this study is the popliteal lymph node of the rabbit challenged by typhoid-O antigen (12). In addition to the microangiograms, histologic sections and imprints (13) were obtained. The weight changes of the lymph node were recorded and antibody titers were periodically determined. Our observations ranged from 3 hr to 75 days. Our histologic findings, the cellular detail on imprints, the weight changes in the lymph node, and the antibody titers were essentially in agreement with previous studies (12-19).General Plan. 31 male, New Zealand white rabbits, weighing approximately 2500 g, were injected with 0.5 ml of febrile antigen, Salmonella group D (typhoid 0), 1 in the left hind footpad. The right side served as a control. At intervals from 3 hr to 75 days microanglography was performed. The removed lymph nodes were weighed, and imprints of the freshly cut lymph nodes were made. Contact microangiograms and histologic sections were obtained and correlated. Typhoid-O antibody titers from the plasma were determined (Table I).

There is constant recirculation of the small lymphocytes from the blood into the lymphatic tissues. The most important route of recirculation is the postcapillary venule (1-5). The small lymphocytes which enter the lymph node from the bloodstream are necessary for the immune response (6 8). Furthermore, it has been suggested that the microcirculation in the lymph node plays a role in antigen uptake (9) and in propagation of the immune response (10). The information concerning cellular interchange between the blood and lymphatic tissues was based on tracer studies, radioautographic examination, and electron microscopy.In spite of the substantial recent information, our knowledge concerning the role of the blood circulation in the immune response is fragmented, and a more comprehensive morphological evaluation of the microvasculature still seems necessary.This investigation was designed to determine the alterations of the microvascular morphology during the course of the p r i m a r y i m m u n e response. T h e evaluation was based on microangiograms and histologic sections. Microangiography is a highly suitable m e t h o d for a detailed study of the microvasculature (11). I t permits an accurate, three-dimensional reconstruction of the capillary and postcapillary structures and can be correlated with the histologic findings. Materials and MethodsThe animal model utilized in this study is the popliteal lymph node of the rabbit challenged by typhoid-O antigen (12). In addition to the microangiograms, histologic sections and imprints (13) were obtained. The weight changes of the lymph node were recorded and antibody titers were periodically determined. Our observations ranged from 3 hr to 75 days. Our histologic findings, the cellular detail on imprints, the weight changes in the lymph node, and the antibody titers were essentially in agreement with previous studies (12-19).General Plan. 31 male, New Zealand white rabbits, weighing approximately 2500 g, were injected with 0.5 ml of febrile antigen, Salmonella group D (typhoid 0), 1 in the left hind footpad. The right side served as a control. At intervals from 3 hr to 75 days microanglography was performed. The removed lymph nodes were weighed, and imprints of the freshly cut lymph nodes were made. Contact microangiograms and histologic sections were obtained and correlated. Typhoid-O antibody titers from the plasma were determined (Table I).

The authors performed direct sagittal computed tomography (CT) on 4 cadaver temporomandibular joints (TMJ) and examined 51 TMJs in 47 patients clinically. The results were correlated with cadaver anatomical sections and clinical arthrographic findings. A fat plane between the bellies of the lateral pterygoid muscles, termed the "lateral pterygoid fat pad," served as the anatomical basis for detection of internal derangements by CT. CT was 94% accurate in detecting meniscal derangements and 96% accurate in detecting degenerative arthritis. The authors suggest that CT rather than arthrography be employed as the primary TMJ imaging modality when internal derangement or arthritis is suspected.