Various high-fat diets are obesogenic but not to the same extent. The aim of the present study was to investigate the effects of saturated fat n-6 and n-3 polyunsaturated fatty acids (PUFAs) on the central neuropeptidergic system in adult rats. Using reverse transcriptase-polymerase chain reaction and in situ hybridisation, we evaluated the net effect of feeding in these fats, comparing the effects of a high- to low-fat diet, and the diversity of the effects of these fats in the same amount within the diet. We also determined plasma lipids, glucose, insulin and leptin concentrations. Six-week feeding with high-saturated fat evoked hyperpahagia and the largest weight gain compared to both high-PUFA diets. Rats fed high-saturated fat were found to have decreased neuropeptide Y (NPY) mRNA expression in the arcuate nucleus (ARC) and the compact zone of the dorsomedial nucleus (DMHc), unchanged pro-opiomelanocortin (POMC), galanin-like peptide (GALP) mRNA expression in the ARC, as well as melanin-concentrating hormone (MCH) and prepro-orexin (preORX) mRNA expression in the lateral hypothalamus, compared to low-saturated fed rats. By contrast, feeding with both high-PUFA diets increased POMC and GALP mRNA expression in the ARC compared to the corresponding low-fat diet and the high-saturated fat diet. Furthermore, feeding with both low-PUFA diets reduced NPY mRNA expression compared to the low-saturated fat diet exclusively in the DMHc. Uniquely, the high n-3 PUFA feeding halved MCH and preORX mRNA expression in the lateral hypothalamus compared to the other high-fat and low n-3 PUFA diets. In rats fed three high-fat diets, plasma insulin and leptin concentrations were significantly increased and the type of fat had no effect on these hormone levels. Rats fed high-saturated fat had both hyperglycaemia and hypertriacylglycerolemia and rats fed high n-3 PUFA only had hyperglycaemia. The present study demonstrates that various forms of dietary fat differentially change the expression of neuropeptide genes involved in energy homeostasis.

Patients with chronic lymphocytic leukemia (CLL) may develop a large-cell transformation known as Richter's syndrome (RS). RS usually presents as diffuse large-cell lymphoma (DLCL) or its immunoblastic variant, and it can be recognized simultaneously with CLL or even 23 yr after its diagnosis. We describe an unusual case of CLL treated with cladribine (2-CdA) in whom DLCL of the plasmablastic type (PBL) developed 4 yr after CLL (Rai IV) diagnosis and 1.5 yr after the 10th course of 2-CdA treatment. Immmunologic, cytogenetic, and molecular studies performed at the time of CLL and PBL coappearance indicated that both tumors originated from different B-cell progenitors. Both malignancies were refractory to VAD (vincristine, doxorubicin, dexamethasone)-based chemotherapy, and only partial response was achieved with CHOP (cyclophosphamide, doxorubicin, vincristine, prednisone) salvage treatment. However, the patient died 6 months after the occurrence of RS due to rapid progression of PBL. This is the first description of a CLL patient who developed an unusual plasmablastic variant of RS. Recently, the PBL entity has been identified among DLCL associated with the human immunodeficiency virus (HIV) infection. We suggest that in our CLL patient heavily pretreated with 2-CdA, PBL arose as a second clone due to the prolonged and severe state of the host's immunosuppression. Overall survival with current strategies is poor, and further insight into the natural history, biology, and treatment of PBL are needed.

No abstract

To cite this article: Szemraj J, Walkowiak B, Kawecka I, Janiszewska G, Buczko W, Bartkowiak J, Chabielska E. A new recombinant thrombolytic and antithrombotic agent with higher fibrin affinity -a staphylokinase variant. I. In vitro study. J Thromb Haemost 2005; 3: 2156-65.Summary. We attempted to construct a new recombinant protein characterized by fibrin-specific properties of plasminogen activation combined with antithrombin and antiplatelet activities. To the C-terminal part of recombinant staphylokinase (r-SAK), which is a promising profibrinolytic agent, we assembled: (i) the Kringle 2 domain (K2) of tissue-type plasminogen activator (t-PA), containing a fibrin-specific binding site, (ii) the RGD sequence (Arg-Gly-Asp) for the prevention of platelet aggregation and (iii) the antithrombotic agent -hirudin. The cDNA for hybrid protein SAK-RGD-K2-Hir was cloned into pESP-3 yeast protein expression vector. The introduction of K2 t-PA, RGD sequence and hirudin into r-SAK molecule did not alter the SAK activity.The plasminogen activation rate (determined by K M and K cat ) of SAK-RGD-K2-Hir was not significantly different from that of r-SAK. Affinity and binding strength of the recombinant protein to fibrin immobilized on the biosensor were higher than to r-SAK. We observed a higher clot lysis potency of SAK-RGD-K2-Hir as evidenced by a faster and more profound lysis of 125 I-labeled human fibrin clots. The potency of thrombin inhibition by the hirudin part of the recombinant fusion protein SAK-RGD-K2-Hir was the same as that of r-Hir alone. In conclusion, the results of the in vitro study suggest that the SAK-RGD-K2-Hir construct can be a more potent and faster-acting thrombolytic agent with antithrombin and antiplatelet properties compared with standard r-SAK.Keywords: antiplatelet activity, hirudin and K2 domain of t-PA, recombinant protein, staphylokinase, thrombolysis, thrombolytic and antithrombotic agents.