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.     

Native serotonin 5-HT3 receptors expressed in Xenopus oocytes differ from homopentameric 5-HT3 receptors

Efficacies of the 5-hydroxytryptamine (serotonin) 5-HT3 receptor (5-HT3R) agonists 2-methyl-5-HT, dopamine, and m-chlorophenylbiguanide on 5-HT3R native to N1E-115 cells and on homopentameric 5-HT3R expressed in Xenopus oocytes were determined relative to that of 5-HT. Efficacies of 2-methyl-5-HT and dopamine on 5-HT3R native to differentiated N1E-115 cells are high (54 and 36%) as compared with their efficacies on homopentameric 5-HT3R-A(L) and 5-HT3R-A(S) receptors expressed in oocytes (4-8%). m-Chlorophenylbiguanide does not distinguish between 5-HT3R in N1E-115 cells and in oocytes. The distinct pharmacological profile of 5-HT3R native to differentiated N1E-115 cells is conserved when poly(A)+ mRNA from these cells is expressed in oocytes. The results indicate that, apart from the known 5-HT3R subunits, N1E-115 cells express additional proteins involved in 5-HT3R function.     

Demonstration of discrete secreted and membrane-bound ocular mucins in the dog

Our aims were to separate and characterize secreted canine ocular mucins, and to provide definitive evidence of membrane-bound mucins at the canine ocular surface. Mucus was collected by suction from the ocular surface of normal dogs and dispersed in guanidine hydrochloride and a cocktail of protease inhibitors. Caesium chloride density gradient centrifugation separated secreted mucins from membranes, which were collected from the top of the gradients. Membranes were extracted with octyl glucoside and screened using lectins and anti-mucin antibodies. Gradient fractions containing secreted mucins were constituted into pools on the basis of differential lectin and antibody staining. High molecular weight material from each pool was purified by gel filtration. This material, and the membrane extract, were reduced and alkylated. Vacuum blotting of separated materials after agarose gel electrophoresis was used to compare subunit structure. Density gradient profiles indicated three principal secreted glycoprotein peaks: one staining strongly with anti-mucin antibodies. Gel filtration demonstrated that each contained high molecular weight material. Vacuum blots demonstrated the presence of two secreted glycoproteins with differently sized subunits. On the basis of buoyant density, one of these may be lipid complexed. Membrane extracted material stained with anti-mucin antibodies, and vacuum blotting of this material provided evidence for two membrane-bound components. In conclusion, we have shown that normal canine ocular mucus contains two secreted mucins, each exhibiting different subunit structure; one of these mucins may undergo lipid complexation. Normal canine ocular mucus also contains two membrane-bound mucins: one of which is unique among membrane mucins in showing subunit structure.     

Presidential reflections

Two direct methods for the diagnosis of trichinellosis were compared: trichinoscopy and artificial digestion. Muscles from 17 wistar rats, orally infected with 500 Trichinella spiralis encysted larvae were examined. From each of the following muscles: diaphragm, tongue, masseters, intercostals, triceps brachialis and cuadriceps femoralis, 648,440 larvae from 1 g samples were recovered. The linear correlation between trichinoscopy and artificial digestion was very high and significant (r = 0.94, p < 0.0001), showing that both methods for the detection of muscular larvae did not differ significantly. In both methods, significant differences were found in the distribution of larvae per gramme of muscle.     

Prolonged neuromuscular blockade with mivacurium in a newborn

Recent reports have demonstrated that puerperal psychosis is preceded by prodromic signs. These signs must be recognized in a multidisciplinary context, opening the way to improved diagnosis, therapy and prognosis. On the basis of our clinical experience, we stress the important of early management in women who present prodromic signs of puerperal psychosis. Specific management relies on intensive psychotherapy with daily sessions centered on filiation. With this approach, the emergence of delusions can generally be prevented, usually allowing an uninterrupted mother-infant relationship. We hypothesize that this approach has a favorable influence on later mother-child interactions and cause profound changes in the mother's psychic organization, resulting in a better long-term prognosis. We illustrate our point with a case report.     

Two reconstructive techniques for flatfoot deformity comparing contact characteristics of the hindfoot joints

The effect of two different methods of reconstruction of flatfoot deformity and the role of the posterior tibial tendon on the contact characteristics of the hindfoot joints were quantified using pressure-sensitive film. Each of 10 cadaver feet was loaded quasi-statically by an axial compressive force to simulate varying loads. First, a specimen was tested intact, then it was tested after sectioning the spring ligament and loading the specimen cyclically to create one type of flatfoot deformity. It was then tested again after reconstructing the deformity. Reconstructions used were the Dillwyn-Evans procedure (bone graft in osteotomy of the calcaneus) or the calcaneocuboid distraction arthrodesis (CCDA). We found that surgically produced flatfoot deformity altered mainly the talonavicular joint, by decreasing its contact area. The Dillwyn-Evans method had less effect on the talonavicular joint (altering 2 of 6 measured parameters) than the CCDA (3 of 6) and more effect on the anteriomedial facet (altering 3 of 6 parameters) than the CCDA (1 of 6). The Dillwyn-Evans method had more effect on the posterior facet (altering 2 of 6 measured parameters) than the CCDA (1 of 6). Function of the posterior tibial tendon had no effect on contact characteristics of the hindfoot joints after either type of reconstruction. These findings are based on measurements using a quasi-statically-loaded foot model at three selected positions, and results may be different with dynamic loading.     

Postsurgical bile leaks: endoscopic obliteration of the transpapillary pressure gradient is enough

OBJECTIVES: Bile leaks are a well documented complication of biliary surgery, occurring more frequently with laparoscopic procedures. Endoscopic therapy with a long biliary endoprosthesis traversing the site of the leak is effective. We have evaluated the hypothesis that equalizing biliary and duodenal pressures with a short transpapillary stent is an equally effective therapy for bile leaks. METHODS: Thirty one consecutive patients presenting over a 52-month period with postsurgical bile leaks were evaluated. Patients had been treated with long endoprostheses (stents or nasobiliary tubes), sphincterotomy, or short transpapillary stents. The success, complication rate, need for additional therapy, and hospitalization time of each therapeutic approach were determined. RESULTS: Endoscopic therapy was successful in all 25 patients in whom a bile leak could be documented. The clinical success, need for radiological drainage, length of hospitalization, and incidence of pancreatitis were similar for all methods of treatment. CONCLUSIONS: These results confirm that endoscopic therapy is highly successful in the treatment of postoperative bile leaks and suggest that the mechanism of healing is the equalization of bile duct and duodenal pressures, allowing flow of bile into the duodenum. The endoscopic placement of short transpapillary stents without sphincterotomy is a temporary, effective, and technically simple method of pressure equalization. This should be considered as the primary therapy for most postoperative bile leaks.