Roles of protein kinase C, Ca2+, Pyk2, and c-Src in agonist activation of rat lacrimal gland p42/p44 MAPK

PURPOSE: Although p42/p44 mitogen-activated protein kinase (MAPK) negatively modulates protein secretion stimulated by cholinergic and alpha(1D)-adrenergic agonists, it does not play a role in epidermal growth factor (EGF)-stimulated protein secretion. Therefore, this study was conducted to determine the roles that protein kinase C (PKC), intracellular Ca(2+) ([Ca(2+)](i)), and nonreceptor tyrosine kinases Pyk2 and Src play in the activation of agonist- and EGF-stimulated MAPK activation. METHODS: Lacrimal gland acini were isolated by collagenase digestion and incubated with phorbol 12-myristate 13-acetate (PMA) to activate PKC or ionomycin, a Ca(2+) ionophore. Acini were preincubated with the PKC inhibitors calphostin C or Ro-31-8220, EGTA to chelate Ca(2+), or the c-Src inhibitor PP1 before stimulation with the cholinergic agonist carbachol, the alpha(1D)-adrenergic agonist phenylephrine, or EGF. Activated MAPK, Pyk2, and c-Src amounts were measured by Western blot analysis. RESULTS: PMA and ionomycin significantly increased the activation of MAPK in a time- and concentration-dependent manner. Inhibition of PKC partially inhibited carbachol-stimulated MAPK activation while completely inhibiting phenylephrine- and EGF-stimulated MAPK activation. Chelation of Ca(2+) also partially inhibited carbachol-stimulated MAPK with no effect on phenylephrine- and EGF-stimulated MAPK activation. Carbachol increased the phosphorylation of Pyk2 on tyrosine 402 and c-src on tyrosine 416 in a time-dependent manner. The c-src inhibitor PP1 inhibited carbachol-stimulated phosphorylation of Pyk2. CONCLUSIONS: It was concluded that cholinergic agonists use Ca(2+) and PKC to phosphorylate Pyk2 and c-Src, which subsequently stimulate MAPK activity. In contrast, alpha(1D)-adrenergic agonists and EGF do not use Pyk2 and Src but do use PKC to activate MAPK.     

Relevance of the criteria commonly used to diagnose myeloproliferative disorder in patients with splanchnic vein thrombosis

Myeloproliferative disorders (MPD) are reported in 25-65% of patients with splanchnic vein thrombosis (SVT). Diagnostic criteria for MPD have not been fully established in this context. Using clusters of abnormal megakaryocytes in bone marrow (BM) biopsy as a reference standard for Philadelphia negative MPD, we assessed the relevance of other criteria currently recommended for the diagnosis of MPD in SVT (128 consecutive SVT patients). First, usual criteria were compared with BM results: endogenous erythroid colony formation (EEC) was strongly correlated with BM results; splenomegaly, blood cell count, total red cell volume, erythropoietin level and cytogenetic were much less accurate. Then, patients were assigned to three groups according to the combination of BM and EEC findings (group I: both present; group II: both absent; group III: other patients); clinical presentation and outcome were compared in each group. At a mean follow-up of 6.09 +/- 6.6 years, progression to a severe form of MPD occurred in 7 of 31 group I patients (23%), in 1 of 34 group III patients (3%) and 0 of 63 group II patients. The combination of marked splenomegaly and platelet count >200 x 10(9)/l was restricted to groups I and III. In conclusion, in patients with SVT, BM findings and EEC allowed the diagnosis of MPD at risk of aggravation. Marked splenomegaly in association with platelet counts >200 x 10(9)/l constitute a simple index with high specificity but low sensitivity.     

Recovery of sickle cell disease ischemic maculopathy after erythropheresis: a clinical case study

The authors report a case of a young patient with a recent decrease in unilateral vision. He had homozygote sickle cell disease with multiple general complications. Fundus examination was normal apart from a mild alteration of the macular reflect in the left eye, but fluorescein angiography showed multiple arteriolar macular occlusions, explaining the decrease in vision in the left eye. After erythropheresis, vision acuity improved and fluorescein angiography showed reperfusion. This case suggests that transfusional exchange may improve acute macular ischemia secondary to sickle cell disease.     

Evolution of the postoperative pericardial effusion after day 15: the problem of the late tamponade

STUDY OBJECTIVES: To evaluate, through clinical and transthoracic echocardiography (TTE) follow-up, the natural history of persistent pericardial effusion (PE) after postoperative day 15 in patients who were given and were not given anticoagulant therapy. DESIGN AND PATIENTS: We retrospectively studied a cohort of 1,277 patients who were hospitalized between May 1997 and May 1999 in our center a mean (+/- SD) time period of 15 +/- 3 days after undergoing coronary artery bypass graft (CABG) surgery (856 patients) or valve replacement (VR) surgery (421 patients). MEASUREMENTS: TTE was performed on mean (+/- SD) postoperative day 20 +/- 1 (TTE(1)) and postoperative day 30 +/- 2 (TTE(2)). PE severity was classified on a scale from grade 1 to grade 4. RESULTS: On postoperative day 20 +/- 1, PE was present in 22% of the 1,277 patients and was more frequent after patients underwent CABG surgery than after undergoing VR surgery (25% vs 17%, respectively; p < 0.01). On postoperative day 30 +/- 2, the overall incidence of late tamponade in patients with PE was 4%. The incidence increased with the severity grade of PE at TTE(1) (p < 0.001). The negative predictive value of a severity grade < 2 at TTE(1) for late tamponade was 100%. Late tamponade incidence was higher after VR surgery than after CABG surgery (11% vs 2%, respectively; p < 0.01), and was higher in patients who had received anticoagulation therapy than in those who had not (8% vs 2%, respectively; p < 0.05). CONCLUSION: Persisting PE is common after postoperative day 15 and is more frequent after undergoing CABG surgery than after undergoing VR surgery. The incidence of late tamponade is usually underestimated, and it increases with the presence of VR, anticoagulation therapy, and/or higher postoperative TTE severity grade. Our data suggest that only patients with a PE severity grade of >/= 2 (< 10% of patients) require TTE follow-up after postoperative day 20.     

Exercise training in cardiac patients: usefulness of the cardiopulmonary exercise test

Exercise training is currently including in the treatment of coronary arterial disease patients, in patients with left ventricular dysfunction as well as in patients who underwent cardiac transplantation or cardiac surgery. However methods of prescribing exercise-training programs are difficult to determine and must be adapted for each patient Exercise test with gas analysis through the determination of anaerobic threshold may help to understand the physiopathological mechanism related to exercise limitation in these patients. Exercise test may help to precise exercise intensity during cardiac rehabilitation and may assess the benefits on exercise tolerance.     

Heart failure and cachexia

Cachexia is related to a malnutrition state related to hypercatabolism. Initially described in cancer, it is also related to several chronic diseases including heart failure. Defined by an unintentional weight loss exceeding 7.5% of body mass during more than 6 months, it is presented by the association of nutritional deficiencies, digestive and/or urinary losses as well as metabolic abnormalities causing fat and lean mass loss and is associated to a poor prognosis. The pathophysiology of cachexia and heart failure presented some similarities associating especially neuro-hormonal activation, a cortisol/DHEA ratio imbalance, as well as pro-inflammatory cytokines activation. Currently the treatment of cachexia is mainly preventive, based on ACE-inhibitors and beta-blockers therapy and physical reconditioning. The benefits of hormonal and nutritional substitutes remains to be evidenced.     

Identification of Tunisian Leishmania spp. by PCR amplification of cysteine proteinase B (cpb) genes and phylogenetic analysis

Discrimination of the Old World Leishmania parasites is important for diagnosis and epidemiological studies of leishmaniasis. We have developed PCR assays that allow the discrimination between Leishmania major, Leishmania tropica and Leishmania infantum Tunisian species. The identification was performed by a simple PCR targeting cysteine protease B (cpb) gene copies. These PCR can be a routine molecular biology tools for discrimination of Leishmania spp. from different geographical origins and different clinical forms. Our assays can be an informative source for cpb gene studying concerning drug, diagnostics and vaccine research.     

Endometrial atypical complex hyperplasia with extensive squamous metaplasia: two cases

We report two cases of endometrial atypical complex hyperplasia with an extensive squamous hyperplasia occurring in two women aged 48 and 31 years old. The histological study showed an increase in the gland to stroma ratio with a false crowding aspect due to an extensive area of squamous metaplasia; some metaplastic areas were centered by necrosis. There was glandular cytologic atypia. Histologic examination is necessary to confirm the diagnosis and to definitively rule out adenocarcinoma.