Role of cytokines in alveolar macrophage accessory cell function in HIV-infected individuals

Mononuclear phagocytes, including alveolar macrophages (AM), can be chronically infected with HIV and thus serve as a reservoir for the virus. Acting as AC during the generation of an immune response, HIV-infected mononuclear phagocytes can facilitate viral T cell infection by several mechanisms, including direct contact of T cells with HIV-infected macrophages as well as cytokine-induced up-regulation of latent T cell infection. Our laboratory has shown that AM from HIV-infected individuals have enhanced AC function compared to normal AM. In this study we explored AM production and secretion of IL-1 beta and IL-6, two cytokines critical for optimal AC function, in normal volunteers and HIV-infected patients. Cultured AM supernatants and lysates were generated in the presence and absence of LPS and standard mitogens. In initial mixing experiments HIV AM supernatants enhanced mitogen-induced T cell proliferation using normal AM as AC significantly more than normal AM supernatants, suggesting that HIV AM secreted more T cell stimulatory factors than normal AM. Neither group could enhance T cell proliferation induced by HIV AM suggesting these cells already secreted optimal levels of these factors. AM from HIV+ individuals produced and secreted more IL-1 beta (measured by ELISA) and IL-6 (measured in a B9 bioassay and by immunoprecipitation) than normal AM both spontaneously and in the presence of low LPS concentrations and mitogens. In some cases depleting HIV AM supernatants of IL-1 beta and IL-6 on immunoaffinity columns abrogated their enhancement properties indicating that these cytokines were important in the observed enhancement. However, in other patients different factors must also be involved as depletion of IL-1 beta and IL-6 in their AM supernatants had no effect on enhancement function. These results show that HIV AM secretory products are important in the enhanced AC function demonstrated by these cells. However, although augmented IL-1 beta and IL-6 secretion likely contribute significantly to this enhancement, other AC secretory factors and/or functions must also be involved.

Role of cytokines in alveolar macrophage accessory cell function in HIV-infected individuals

Mononuclear phagocytes, including alveolar macrophages (AM), can be chronically infected with HIV and thus serve as a reservoir for the virus. Acting as AC during the generation of an immune response, HIV-infected mononuclear phagocytes can facilitate viral T cell infection by several mechanisms, including direct contact of T cells with HIV-infected macrophages as well as cytokine-induced up-regulation of latent T cell infection. Our laboratory has shown that AM from HIV-infected individuals have enhanced AC function compared to normal AM. In this study we explored AM production and secretion of IL-1 beta and IL-6, two cytokines critical for optimal AC function, in normal volunteers and HIV-infected patients. Cultured AM supernatants and lysates were generated in the presence and absence of LPS and standard mitogens. In initial mixing experiments HIV AM supernatants enhanced mitogen-induced T cell proliferation using normal AM as AC significantly more than normal AM supernatants, suggesting that HIV AM secreted more T cell stimulatory factors than normal AM. Neither group could enhance T cell proliferation induced by HIV AM suggesting these cells already secreted optimal levels of these factors. AM from HIV+ individuals produced and secreted more IL-1 beta (measured by ELISA) and IL-6 (measured in a B9 bioassay and by immunoprecipitation) than normal AM both spontaneously and in the presence of low LPS concentrations and mitogens. In some cases depleting HIV AM supernatants of IL-1 beta and IL-6 on immunoaffinity columns abrogated their enhancement properties indicating that these cytokines were important in the observed enhancement. However, in other patients different factors must also be involved as depletion of IL-1 beta and IL-6 in their AM supernatants had no effect on enhancement function. These results show that HIV AM secretory products are important in the enhanced AC function demonstrated by these cells. However, although augmented IL-1 beta and IL-6 secretion likely contribute significantly to this enhancement, other AC secretory factors and/or functions must also be involved.

Monocyte accessory cell function in patients infected with the human immunodeficiency virus

Previous studies suggested that peripheral blood monocytes (Mo) from HIV-infected patients were poor accessory cells (AC), although most of these studies were limited by using autologous T cells as responders. Using allogeneic T cells from uninfected volunteers as responders, the current studies demonstrate that Mo from infected individuals were comparable to Mo from uninfected volunteers as AC in Con A and pokeweed mitogen-stimulated lymphocyte proliferation assays, but were inferior to normal Mo in stimulating a mixed leukocyte reaction. This deficiency was not explained by HIV Mo-induced suppression of lymphoproliferation or by death of responding CD4 lymphocytes induced by HIV transmission from infected Mo in 6-day MLR cultures. Mo from HIV-infected patients retained the ability to stimulate mumps-specific T cell lines in response to antigen, demonstrating that Mo from these individuals could process and display antigen on their cell surface in association with a functional DR molecule. Taken together these results suggest that Mo from HIV-infected patients (i) retain the ability to act as AC in T cell responses to mitogenic signals or to stimulate already activated antigen-specific T cells, but (ii) fail to stimulate resting and/or unprimed T cells in response to alloantigen and perhaps de novo antigen exposure. It is possible this Mo defect may have an adverse effect on the immune responsiveness of HIV-infected individuals.

Enhanced accessory cell function by alveolar macrophages from patients infected with the human immunodeficiency virus: potential role for depletion of CD4+ cells in the lung

Mononuclear phagocytes, including alveolar macrophages (AM), can be infected by the human immunodeficiency virus (HIV). Acting as accessory cells (AC), AM could infect CD4 lymphocytes through cell-to-cell contact and by inducing T cell proliferation, which increases lymphocyte susceptibility to infection. Using normal allogeneic T cells as responders, AM from infected individuals demonstrated an enhanced ability to stimulate a Con A and pokeweed mitogen lymphocyte proliferation assay compared with normal AM. Exogenous IL 1 enhanced the stimulation of a mitogen response by normal AM, but not from HIV-positive individuals, suggesting increased levels of this cytokine may explain the observed enhancement. However, increased IL 1 secretion by AM from HIV-infected patients could not be demonstrated, either in a bioassay or antigenically using an ELISA for IL-1 beta. Syncytia formation was observed when AM from asymptomatic HIV-positive individuals were cultured with normal T cells, suggesting viral transmission was occurring. Finally, in individual patients the stimulation of a mitogen response was inversely correlated with the CD4/CD8 ratio and total CD4 count, suggesting that enhanced AC function and CD4 cell depletion may be related in vivo. These findings indicate that enhanced AM accessory cell function is seen in HIV-infected individuals and could be a potential mechanism for CD4 cell depletion in the lung.

Radiographic diagnosis of tonsillar cyst presenting as dysphagia

Tonsillar retention cysts are common and most often asymptomatic. The radiographic demonstration of a retention cyst in a symptomatic patient is reported. Emphasis should be placed on the oropharynx during barium swallow examinations in appropriately symptomatic patients. Tonsillar retention cysts should be included in the differential diagnosis of mass lesions in this area.

Perforated viscus presenting with gas in the soft tissues (subcutaneous emphysema)

We have reviewed the spectrum of gaseous densities in the soft tissues secondary to a perforated viscus. All patients presented late and most were elderly. The most common surgical procedure was diversion of the fecal stream proximal to the perforation. In our series 4 of 7 patients died in the immediate postoperative period. Knowledge of the mechanism and differential diagnosis of this entity will prevent overlooking this possibility, as occurs too frequently, particularly with subcutaneous emphysema of the leg.

Radiographic appearance of the thorax in systolic click-late systolic murmur syndrome

The posteroanterior and lateral chest X-ray films of 64 consecutive patients with an isolated systolic click (55 patients) or a systolic click with a late systolic murmur (9 patients) showed a striking frequency of thoracic skeletal abnormalities. There were 50 female and 14 male subjects. The average age of the female subjects was 36.7 years (range 13 to 67), that of the male subjects 39.7 years (range 17 to 56). Seventy-two percent of the female and 78 percent of the male subjects had an anteroposterior/transverse thoracic ratio less than the mean ratio in a small population. Bony abnormalities such as pectus excavatum, straight thoracic spine and scoliosis occurred alone or in a combination in 31 of the 50 female patients (62 percent) and in 8 of the 14 male patients (57 percent). Overall, 39 of the 64 patients (61 percent) had at least one of the skeletal abnormalities. Scoliosis occurred in 25 subjects (39 percent) and was mild in 19. A "straight back" was found in 15 (23 percent) and pectus excavatum in 7 patients (11 percent). The explanation for these findings is not apparent. Thoracic cage abnormalities should be included as one of the nonauscultatory features of the systolic click-late systolic murmur syndrome.

Early clinical experience with the ACTA scanner

An alternative method of computed tomography has been devised employing a new instrument, the ACTA scanner. This is a total-body scanner which permits study of virtually all body parts, since a water medium is not employed. Early clinical experience with this new method is discussed, and normal and pathological scans are presented.

Computerized axial tomography in syringomyelia

The ACTA-scanner, a device for computerized axial tomography, permits cross-sectional radiographic study of the entire human body, including the spine. In the ACTA-scan, the spinal cord appears as a roundish formation surrounded by the less dense subarachnoidal cerebrospinal fluid. The spines of 18 patients with verified (nine cases) or suspected (nine cases) syringomyelia were studied by ACTA-scanning. In seven of the verified and in four of the nonverified cases, some evidence of cord cavitation was shown. The cystic part of a cervical-cord ependymoma was also demonstrated. ACTA-scanning is an easily performed, noninvasive, innocuous procedure. This technic, which complements other radiographic methods of evaluating the spinal cord, is particularly suitable for screening and follow-up study of patients with syringomyelia. The easily accomplished recognition of a possible associated hydrocephalus is an added advantage of ACTA-scanning.

Computerized transaxial x-ray tomography of the human body

The ACTA-Scanner has virtually unlimited potential in the evalution of any part of the body. The usefulness of the technique has already been shown in the appraisal of pathologies of the brain and cerebrospinal fluid cavities. The orbits and the eyeballs, the facial sinuses, and skull base lesions have also been elucidated. Tumors of the larynx, pharynx, thyroid, and parathyroid; lymphomas; and pathology of the spine and spinal cord are well within the reach of this new diagnostic methodology. Lung pathologies, such as emphysema, pneumonias, neoplasms, infarctions, pleural effusions and granulomatous diseases, and mediastinal pathology represent a challenging complex of lesions to be appraised by ACTA-scanning. For the heart, there is great potential for observing cardiac chamber size, hypertrophy of ventricular or atrial walls, and ventricular or aortic aneurysms, and possibly for recognizing the damaged myocardial tissue immediately after or some time after an infarction. The abdominal pathologies that can be studied are almost uncountable: gastric neoplasms, pancreatic cysts and stones, gallstones, neoplasms of the liver and pancreas, bowel tumors, abdominal aortic aneurysms, renal neoplasms and cysts, atrophy of the kidneys, bladder tumors, uterine tumors, ovarian cysts, and many more. Although bones and joints are adequately demonstrated by conventional x-ray techniques, there is no doubt that as the new technique is developed ACTA-grams will contribute significant information in the transverse plane, as well as in densitometric analyses. The impact of ACTA-scanning will not be limited to the diagnostic area, but will extend, at least indirectly, to general patient management and to some aspects of medical economics as well. Risk-laden, technically complex, and costly diagnostic procedures, sometimes requiring lengthy hospitalization, will in some cases be eliminated. The simple, innocuous, and noninvasive ACTA-scanning can be performed on an outpatient basis. Repeated follow-up examinations should be easily accepted by the patients, considering that this diagnostic test is carried out without discomfort. The entire field of diagnostic radiology is on the verge of revolutionary changes.

Shadows bordering the lung on radiographs of normal and obese persons

The thickness of the shadows that accompany ribs or border the lungs on the chest postero-anterior radiographs of 22 obese patients and 22 normal-weight subjects was measured, when present, at several rib levels. A similar measurement was made of accompanying rib shadows on chest postero-anterior radiographs of eight obese patients after weight reduction. Statistical analysis showed that there were significantly thicker soft tissue shadows adjacent to the ribs of obese subjects compared to normal-weight persons and of obese subjects before as compared to after weight reduction. Such shadows are more frequent and are seen at more rib levels of the obese.

In addition, the following pertinent features are discussed: the mechanism by which soft tissue projects a radiographic shadow, the factors affecting its appearance, and the significance of such shadows as a variant of the normal chest radiograph and not as a manifestation of pathology.