Evaluation of brain and epidural abscesses by computed tomography

Most brain abscesses have a characteristic but nonspecific appearance on computed tomography (CT), consisting of a ring configuration of the abscess capsule which shows marked enhancement after injection of contrast material. CT scanning is invaluable in both the initial investigation of a brain abscess and assessment of its response to therapy. The CT scan showed a peripheral low-density crescent in one case of epidural abscess.

The formation of cis-3-nonenal, trans-2-nonenal and hexanal from linoleic acid hydroperoxide isomers by a hydroperoxide cleavage enzyme system in cucumber (Cucumis sativus) fruits

1. A particulate enzyme fraction and an acetone powder preparation from cucumber fruits cleaved 9- and 13-hydroperoxyoctadecadienoic acids to form volatile aldehydes and oxoacid fragments. 2. From the 9-hydroperoxide, the major volatile fragments were cis-3-nonenal and trans-2-nonenal using particulate enzyme and acetone powder preparations, respectively. 3. Hexanal was the only significant volatile fragment from the 13-hydroperoxide. 4. The particulate enzyme system was equally effective on both 9- and 13-hydroperoxide isomers and was fully active under anaerobic conditions and at pH 6.4. 5. An enzymic pathway for the biogenesis of hexanal, cis-3- and trans-2-nonenal (components of the characteristic flavour volatiles of cucumber) from linoleic acid is proposed. This involves the sequential activity of lipoxygenase, hydroperoxide cleavage and cis-3-: trans-2-enal isomerase enzymes.

An evaluation of screen-film speed characteristics

The relative speeds of six commercially available screen-film combinations were evaluated. There is a nonlinear relationship throughout the kVp range between the calcium tungstate, barium strontium sulfate, and rare earth screens. The speed of the last two types falls off considerably at lower kVp levels.

Chest physiotherapy and the distribution of ventilation

The injured or postoperative thorax is commonly treated with physiotherapy employing "unilateral breathing" techniques. The ability of these methods to alter the distribution of ventilation and blood flow (oxygen uptake) was examined in four patients undergoing bronchospirometry. No change was observed in these measurements in the lung toward which efforts were being directed to either enhance or restrict the mechanics of breathing. To further examine the problem, two susceptible subjects were hypnotized following intubation for bronchospirometry, and emotional and physical states were suggested that limit motion in one hemithorax. This included the presence of pleuritic pain in one subject who had ample experience with this symptom. In no instance did we find a change in the distribution of ventilation or blood flow to the lung that was supposed to be limited; however, in 17 subjects, lying on one side produced a significant increase in ventilation and blood flow in the dependent lung. Lying on one side or the other consistently and predictably modified ventilation and blood flow, while attempts to produce similar changes by voluntary intention or commonly applied mechanical aids were ineffective.

Some cellular aspects of chronic inflammation in joint disease

We have examined the nature of some mononuclear cells from inflamed synovial membranes of patients with rheumatoid arthritis. It was found that cells which remained in the supernatant medium after overnight culture of trypsinized tissue contained a variable number of lymphocytes which were shown to be T cells by rosetting and mitogen response. This suggests a source of T cell lymphokines with an effect on macrophages and thus a role in the maintenance of inflammation. Another role for mononuclear cells is suggest by the cytotoxicity of blood mononuclear cells directed against cultured synovial cells. This was found to occur in an autologous system using fibroblasts from rheumatoid synovium, but was not specific for rheumatoid arthritis. Stimulatory factors from rheumatoid joint effusion macrophages for blood lymphocytes were sought, but although blast transformation occurred, the results were equivocal. In this communication we set out to examine the nature of lymphoid cells in the synovial membrane and the role which they may play in the pathogenesis of chronic inflammation. We also briefly consider cell-mediated mechanisms of tissue injury. Since an active role of lymphoid cells pre-supposes the presence of an agent or agents which serve to stimulate them, we also report some recent attempts to find evidence for this. One of the striking histological features of the inflamed synovial tissue in rheumatoid arthritis, but also in some other forms of chronic arthritis, is the presence of lymphocytes and plasma cells. Immunofluorescent studies and organ culture studies have shown the presence and synthesis of immunoglobulins, predominantly the domain of plasma cells. The production of immunoglobulins, formation of complexes and activation of complement is a major factor in pathogenesis, but lymphocytes may also have a direct role through the production of lymphokines. Until recently these substances have been attributed to T lymphocytes, but Rocklin et al. (1) have recently shown that B cells may also be involved in certain experimental circumstances. The availability of synovectomy specimens from patients with rheumatoid arthritis has enabled us to examine the nature of lymphoid cells from synovial membranes. (This part of the work is reported fully elsewhere.

Study of lymphoid cells from inflamed synovial membranes

Synovectomy specimens from patients with rheumatoid arthritis were cultured and after 24 hours the nonadherent cells were removed. These were found to include cells with the morphological characteristics of lymphocytes. Using the sheep-cell rosetting test, up to 94% of these cells were found to be T cells, and while T cells could be found in all the supernatant cell populations studied, not all made a mitogen response. None or only a very small number of B cells were found by staining for surface immunoglobulin. The possible roles which T lymphocytes might play in chronic inflammation in the rheumatoid synovium are discussed in relation to experimental work, and factors which attract T cells into areas of nonspecific inflammation are similarly considered in the light of animal experiments.

Radiographic manifestations of malignant mixed uterine tumors

Malignant mixed uterine tumors have a varied radiographic appearance. The primary tumor is usually evident as an enlarged uterus, frequently with localized, faint, punctate calcification. New or increasing calcification within an enlarging uterus of a postmenopausal female should raise the suspicion of mixed malignant uterine tumor. Metastases are common, and usually involve the lung, most often becoming apparent quite rapidly. The pattern of pulmonary metastases is varied from large masses to lymphangitic spread, hilar lymph nodes and pleural effusions being common. Calcification within pulmonary secondaries may occur and cavitation has been observed.