Pelvic myeloid sarcoma: a multidisciplinary approach.

Myeloid sarcoma (MS) is a rare tumor mass derived from the extramedullary proliferation of blasts of one or more of myeloid lineages. It usually occurs at an anatomical site other than the bone marrow (BM). Among the anatomical site which may be involved, female genital tract is a rare localization. When MS follows a previous history of myeloid pathology it is usually associated to a poor prognosis. To date this disease was managed with exploratory laparotomy or with surgical debulking. The authors report a case of laparosc6pic diagnosis of a pelvic myeloid sarcoma in a patient previously affected by acute mycloid leukemia, evidencing the importance of minimally invasive diagnosis and subsequent multidisciplinary management.

Comparative proteomic profiling of Hodgkin lymphoma cell lines.

Classical Hodgkin lymphoma (cHL) is a malignancy with complex pathogenesis. The hallmark of the disease is the presence of large mononucleated Hodgkin and bi- or multinucleated Reed/Sternberg (H/RS) cells. The origin of HRS cells in cHL is controversial as these cells show the coexpression of markers of several lineages. Using a proteomic approach, we compared the protein expression profile of cHL models of T- and B-cell derivation to find proteins differentially expressed in these cell lines. A total of 67 proteins were found differentially expressed between the two cell lines including metabolic proteins and proteins involved in the regulation of the cytoskeleton and/or cell migration, which were further validated by western blotting. Additionally, the expression of selected B- and T-cell antigens was also assessed by flow cytometry to reveal significant differences in the expression of different surface markers. Bioinformatics analysis was then applied to our dataset to find enriched pathways and networks, and to identify possible key regulators. In the present study, a proteomic approach was used to compare the protein expression profiles of two cHL cell lines. The identified proteins and/or networks, many of which not previously related to cHL, may be important to better define the pathogenesis of the disease, to identify novel diagnostic markers, and to design new therapeutic strategies.

Inhibition of rapamycin-induced autophagy causes necrotic cell death associated with Bax/Bad mitochondrial translocation.

Rapamycin, a lipophilic macrolide antibiotic, has been found to reduce injury in different models of neurodegenerative disorders. We have previously shown that in neonatal rats subjected to hypoxia-ischemia (HI) the neuroprotective effect of rapamycin was associated with increased autophagy and decreased caspase-3 activation. We show here that the strong reduction of caspase-3 activation after rapamycin was due, at least in part, to its effect on the intrinsic apoptotic mitochondrial pathway because after rapamycin treatment there was a marked reduction of Bax and Bad translocation to mitochondria, cytochrome c release, and caspase-3 activation. Poly (ADP-ribose) polymerase 1 (PARP-1) cleavage and the number of terminal dUDP nick-end labeling (TUNEL)-positive cells were also reduced. To assess how the antiapoptotic effect of rapamycin was linked to the strong autophagy signal induced by the drug, we blocked the formation of autophagosomes with 3-methyladenine (3MA). 3MA administered 10 min after rapamycin, elicited again Bax and Bad translocation to the mitochondria but did not cause cytochrome c release and caspase-3 activation. After 3MA treatment, cells underwent necrotic cell death. These data indicate that rapamycin administered before HI prevents the apoptotic signaling taking place through the mitochondrial pathway. We hypothesize that rapamycin confers a preconditioning-like protection and suggest that caution is necessary before using pharmacological agents targeting autophagy in neuroprotection because they could interfere with endogenous protective mechanisms.

In vitro and in vivo antitumor efficacy of docetaxel and sorafenib combination in human pancreatic cancer cells.

The response of pancreatic cancer to treatments remains unsatisfactory, highlighting the need for more effective therapeutic regimens. Sorafenib, an orally available multikinase inhibitor, is active against different tumors, including pancreatic cancer. We studied the antitumor efficacy of sorafenib in combination with different antitumor drugs currently used in clinical practice in in vitro and in vivo experimental models of human pancreatic cancer. The cytotoxic effect of sorafenib and conventional antitumor drug combinations was evaluated in vitro in human pancreatic cancer cell lines and the efficacy of the most active combination was tested on tumor-bearing mice. Flow cytometric, Western blot and immunohistochemistry analyses were performed to investigate the mechanisms involved in the activity of single drugs and in their interaction when used in combination. Sorafenib showed a strong sequence-dependent synergistic interaction in vitro with docetaxel, which was highly dependent on the drug sequence employed. In vivo, human pancreatic cancer-xenografted mice treated with docetaxel followed by sorafenib reduced and delayed tumor growth, with complete tumor regression observed in half of the mice. This marked antitumor effect resulted in an overall increase in mouse survival of about 70% and in a complete cure in 3 of the 8 treated mice. The strong activity was also accompanied by marked apoptosis induction, inhibition of tumor angiogenesis and downregulation of ERK signalling. Our results show that the docetaxel and sorafenib combination exerts high therapeutic efficacy in experimental models of human pancreatic cancer, indicating a promising antitumor strategy for clinical use.

Serine 124 completes the Tyr, Lys and Ser triad responsible for the catalysis of human type 1 3beta-hydroxysteroid dehydrogenase.

Human 3beta-hydroxysteroid dehydrogenase/isomerase (3beta-HSD) is a key steroidogenic enzyme that catalyzes the first step in the conversion of circulating dehydroepiandrosterone (DHEA), pregnenolone or 17alpha-hydroxypregenolone to produce the appropriate, active steroid hormone(s): estradiol, testosterone, progesterone, aldosterone or cortisol respectively. Our mutagenesis studies have identified Tyr154 and Lys158 as catalytic residues for the 3beta-HSD reaction. Our three-dimensional homology model of 3beta-HSD shows that Tyr154 and Lys158 are oriented near the 3beta-hydroxyl group of the bound substrate steroid, and predicts that Ser123 or Ser124 completes a Tyr-Lys-Ser catalytic triad that operates in many other dehydrogenases. The S123A and S124A mutants of human type 1 3beta-hydroxysteroid dehydrogenase/isomerase (3beta-HSD1) were created by PCR-based mutagenesis, expressed in insect cells using baculovirus and purified to homogeneity. The S124A mutant exhibits no 3beta-HSD activity and has a K(m) value (83.6 microM) for the isomerase substrate that is threefold greater than that of wild-type 1 isomerase. In contrast, S123A has substantial 3beta-HSD activity (DHEA K(m)=11.2 microM; k(cat)=0.8 min(-1)) and utilizes isomerase substrate, 5-androstene-3,17-dione, with a K(m) value (27.6 microM) that is almost identical to wild-type. The K(m) value (4.3 microM) of S124A for NADH as an allosteric activator of isomerase is similar to that of the wild-type 1 enzyme, indicating that Ser124 is not involved in cofactor binding. S123A utilizes NAD as a cofactor for 3beta-HSD and NADH as the activator for isomerase with K(m) values that are similar to wild-type. The 3beta-HSD activities of S123A and wild-type 3beta-HSD increase by 2.7-fold when the pH is raised from 7.4 to the optimal pH 9.7, but S124A exhibits very low residual 3beta-HSD activity that is pH-independent. These kinetic analyses strongly suggest that the Ser124 residue completes the catalytic triad for the 3beta-HSD activity. Since there are 29 Ser residues in the primary structure of human 3beta-HSD1, our homology model of the catalytic domain has been validated by this accurate prediction. A role for Ser124 in the binding of the isomerase substrate, which is the 3beta-HSD product-steroid of the bifunctional enzyme protein, is also suggested. These observations further characterize the structure/function relationships of human 3beta-HSD and bring us closer to the goal of selectively inhibiting the type 1 enzyme in placenta to control the timing of labor or in hormone-sensitive breast tumors to slow their growth.

[Magnetic resonance arthrography in chronic wrist pain]. / Artrografia con Risonanza Magnetica (artro-RM) nelle malattie dolorose croniche del polso.

PURPOSE: To investigate the clinical role of Magnetic Resonance Arthrography (MRA) of the wrist in subjects with chronic pain. MATERIAL AND METHODS: Thirty-five patients complaining of wrist pain for more 6 months were submitted to MRI and MRA. All patients received an intra-articular (monocompartment radiocarpal joint) injection of 2-10 mL of a 10 mmol saline solution of Gd-DPTA. Two radiologists independently evaluated the conspicuity of the intrinsic intercarpal ligaments and of the triangular fibrocartilage complex and expressed it on a 3-grade semiquantitative scale. On MRI images, complete visualization of the two structures was graded as 0, partial visualization as 1 and no visualization as 2. On MRA images, no contrast agent passage through the ligament or the complex was graded as 0, minimal passage as 1 and complete passage as 2. Sixteen patients had surgical confirmation (arthroscopy in 10 and open surgery in 6 patients). RESULTS: On MRI images the scapholunate ligament was completely visualized in 7 patients (21%) and partially or not visualized in 28 patients (89%). MRA images showed an intact ligament in 15 cases (44%) and a partial or total tear in 20 cases (48% and 8% respectively, 56% in all). On MRI images the luno-pyramidal ligament was completely visualized in 6 patients (18%) and partially or not visualized in 29 cases (82%). On MRA images the luno-pyramidal ligament was intact in 21 cases (58%) and had a partial or total tear in 14 cases (27% and 15% respectively, 42% in all). On MRI images the triangular fibrocartilage complex was normal in 27 cases (76%) and it was only partially visualized in 8 cases (24%). On MRA images the triangular fibrocartilage complex was normal in 13 cases (37%) and had a partial injury in 22 cases (63%). There were no severe side-effects to contrast agent injection, nor severe complications. The overall diagnostic accuracy rates of MRI and MRA were 40% and 81% respectively, with sensitivity and specificity of 63% and 39% (MRI) and of 82% and 79% (MRA). CONCLUSIONS: Compared with MRI, MRA can be considered a useful tool for the visualization of interosseous carpal ligaments and of the triangular fibrocartilage complex. MRA also helps detect injuries in these structures.

Plantar fibromatosis: an immunohistochemical and ultrastructural study.

The analogies between plantar fibromatosis and Dupuytren's disease (palmar fibromatosis) are well known. The latter is clinically more frequent and has been the object of extensive immunohistochemical and ultrastructural studies, with a view to investigating its pathogenesis. By contrast, such data on plantar fibromatosis are quite scarce. A histochemical, immunohistochemical, and ultrastructural study was performed on nodule tissue from six patients who were subjected to total fasciectomy for plantar fibromatosis. The study of myofibroblasts revealed features suggestive of their fibroblastic origin and evidenced a cytoskeleton and an extracellular filamentous system that could enable myofibroblasts to generate and exert the intracellular forces that contribute to the contraction of the aponeurosis. These aspects are similar to those observed in Dupuytren's disease and seem to lend support to the theory that the two diseases are expressions of the same disorder.

[Magnetic resonance arthrography in chondral disease of the knee]. / L'artrografia con Risonanza Magnetica nella malattia condrale del ginocchio.

The clinical usefulness of Magnetic Resonance Imaging (MRI) of the knee in the depiction of meniscal, ligament and tendon lesions is well known. In contrast, the role MRI plays in the diagnosis of chondromalacia remains debated, the gold standard being arthroscopy. A new technique, i.e., MR arthrography (MRA), has been recently proposed which consists of the intraarticular injection of a paramagnetic contrast agent (Gd-DTPA) during MRI. Thirty-one patients with clinically suspected chondromalacia of the knee were examined with MRA. The exams were performed with a 1T superconductive magnet and a dedicated coil. All the patients were examined before (baseline scans) and after paramagnetic contrast agent injection. MRA results were compared with arthrographic findings. Baseline MRI had 25% sensitivity, 77.9% specificity and 83% diagnostic confidence in the diagnosis of chondromalacia; these figures increased to 93%, 97.6% and 91.5% after contrast agent injection. This preliminary experience confirms MRA to be a useful tool in the diagnosis of chondral knee conditions.

MR findings in post-traumatic carpal tunnel syndrome.

Stenosis of the canal secondary to poor consolidation of fractures of the distal radial epiphysis is one of the causes of compression on the median nerve of the wrist. Other post-traumatic compressive pathologies of the median nerve when there are no significant skeletal modifications caused by probable involvement of the soft tissues surrounding and within the canal are also described. MR was used to study 23 patients affected with the sequelae of fracture of the radial distal epiphysis who presented with clinical and electromyographic signs of carpal tunnel syndrome, and were submitted to decompressive surgery. MR showed indirect signs of compression, such as morphological changes of the median nerve, as well as post-traumatic changes in the carpal canal. MR allows for a complete anatomical view of the canal structures implicated in causing post-traumatic carpal tunnel syndrome.