Intravenous long term infusions of the rat without anesthesia

The lumbar-spine radiographs of 67 patients with idiopathic chondrocalcinosis articularis were reviewed for disc calcification and other changes. Calcification was present in 21 (31%) of the patients, seen most frequently at the L 2-3 disc space. The 21 patients as a group were significantly older than the 46 patients without disc calcification, and also had a much higher incidence of chondrocalcinosis in peripheral joints. There was no association with back pain or spinal stiffness. The 21 patients with disc calcification included six patients with a destructive peripheral arthropathy, and three of them had destructive changes affecting the lumbar spine. Three patients with a destructive peripheral arthropathy were also included in the group without disc calcification, and one of these had a destructive arthritis of the lumbar spine. For comparison, there was a 55% incidence of spinal chondrocalcinosis in nine patients with primary hyperparathyroidism and peripheral joint chondrocalcinosis, and a 6% incidence in 100 anteroposterior lumbar spine radiograph 'controls', taken before intravenous urography, although in this latter group the changes were minimal and confined to the margin of a single disc in each case.     

Histometric study of meat products. A literature review

In the present paper, the literature on the development of methods for histometric monitoring the quality of meats is reviewed. The value of specific techniques, statistical interpretation of results and the practicability of automation of histometric analysis are examined more closely. It is concluded from the study of the literature that histometric examination of meats allows an objective assessment of volume percentages of tissue components. When a distinct difference in contrast between various tissues is achieved by specific staining methods, developments in the field of image analysis systems will allow automation of the quantitative histological examination of meats.     

On the generalization of state feedback decoupling theory

The theory of state-variable feedback decoupling in multivariable control systems is generalized to include the case where a subset of the output set is the candidate for decoupling. Systems in which such decoupling is employed will be termed "partially decoupled." Decoupling a selected set of outputs, when achieved by using a state feedback matrixFand a nousingular (m times m) input matrixG, will be calledm-input decoupling (MID), to reflect the restriction on the input matrix. An algorithm, developed by Silverman for constructing inverse systems, is shown to play an essential role in the MID problem, and using matrices constructed in the algorithm, necessary, and sufficient conditions form-input decoupling the specified set of outputs are obtained. As would be expected, these necessary and sufficient conditions include the existing conditions for decoupling all system outputs as a special case. An example is given illustrating the results.     

MMP and TIMP expression pattern in pleural effusions of different origins

The matrix metalloproteinases (MMP) are proteolytic enzymes that are essentially involved in the turnover of the extracellular matrix (ECM). Their activity is counterbalanced by specific antagonists, the tissue inhibitors of metalloproteinases (TIMP). In this study, we sought to analyze the expression of MMP and TIMP isoforms in pleural effusions from 88 patients. We compared MMP and TIMP isoform expression in transudates (n = 21) and exudates (n = 67), the latter divided into exudates of paraneoplastic (n = 46) or parainfectious (n = 21) origin. Zymographic and Western blot analyses revealed constant expression of interstitial collagenase (MMP-1), gelatinase-A (MMP-2), and TIMP-1 in all 88 samples. In contrast, analyses of gelatinase-B (MMP-9) demonstrated a specific expression pattern, with high expression in exudates and lack of expression in transudates. Neutrophil collagenase (MMP-8) was detected in trace amounts, and correlated with the number of neutrophils in the effusion. Low levels of TIMP-2 were detected only in exudates and not in transudates. Quantitative analysis of the expression ratio of gelatinase-B to gelatinase-A revealed statistically significant differences between effusions of different origin. The ratio was highest in exudates of paraneoplastic origin and lowest in transudates. Our data thus suggest that interstitial collagenase, gelatinase-A, and TIMP-1 play a role in homeostasis of the pleural space in vivo as constitutively expressed proteins, whereas gelatinase-B and TIMP-2 expression are induced in specific disease states. These observations contribute to the understanding of the pathophysiology of pleural effusions, and may help to characterize and possibly distinguish effusions of different origin.