Investigation of the Physical Properties of Poly(ortho‐ and para‐trifluoromethoxy styrenes)

Ortho and para ‐OCF₃ substituted styrenes are prepared by the Grignard cross‐coupling reaction between ‐OCF₃ substituted bromobenzene and vinyl bromide and further polymerized in bulk using benzoyl peroxide. The glass‐transition temperatures (T_g) are 80 °C and 73 °C for the ortho and para –OCF₃ substituted polystyrenes, respectively, which are much lower compared with polystyrene (100 °C). The size of the ‐OCF₃ group is large and the ether bond is flexible; thus, the ‐OCF₃ substituted polystyrenes have larger free volumes, which has more effect on the T_g value compared with that of the steric hindrance effect. The refractive indices are 1.4908 and 1.4809 at 650 nm for ortho and para –OCF₃ substituted polystyrenes, respectively, which are much lower than that of polystyrene (1.5861) due to the presence of fluorine atoms in the polymer unit.

     

Improvement of bone repair with l-PRF and bovine bone in calvaria of rats. histometric and immunohistochemical study

Clinical Oral Investigations - The effect of leucocyte- and platelet-rich fibrin (L-PRF), associated with DBBM (deproteinized bovine bone mineral; Bio-Oss®) was investigated and compared with...     

Pancreatic Follicular Lymphoma Presenting as Acute Pancreatitis: Report of a Case

Pancreatic B-cell lymphoma is rare; it accounts for 0.2% to 2.0% of extranodal non-Hodgkin lymphoma, and constitutes less than 0.5% of all pancreatic malignancies. Most histologic types of the pancreatic lymphoma are diffuse large B-cell lymphoma, and follicular lymphoma is quite rare. We report here a case of pancreatic follicular lymphoma that was initially detected by acute pancreatitis. This is the first reported case of pancreatic follicular lymphoma presenting with acute pancreatitis. A 71-year-old woman had epigastric and left upper quadrant abdominal pain. Computed tomography (CT) revealed features of acute pancreatitis. After standard therapy for pancreatitis, enhanced CT showed a pancreatic tumor (50 × 35 mm) in the body of the pancreas with gradual enhancement. Endoscopic retrograde cholangiopancreatography and magnetic resonance cholangiopancreatography showed a complete interruption of the pancreatic duct in the body, with mild dilation of the duct in the tail of the pancreas. Endoscopic ultrasonography revealed hypervascularity of the pancreatic tumor. The patient underwent distal pancreatectomy to remove the cause of pancreatitis and to disclose the diagnosis. Histologic examination revealed follicular lymphoma of pancreas. Despite recent improvement in clinical strategies, differential diagnosis between pancreatic lymphoma and pancreatic cancer is still difficult without histologic information. Pancreatic lymphoma should be considered as a differential diagnosis in a patient who initially presents with acute pancreatitis.Key words: Pancreatic lymphoma, Acute pancreatitis, Follicular lymphomaPancreatic B-cell lymphoma is rare; it accounts for 0.2% to 2.0% of extranodal non-Hodgkin lymphoma¹ and constitutes less than 0.5% of all pancreatic malignancies.^2,3 Most histologic types of pancreatic lymphoma are diffuse large B-cell lymphoma, and follicular lymphoma is quite rare. In addition, acute pancreatitis caused by pancreatic lymphoma is also rare.Despite recent improvements in clinical strategies, differential diagnosis of pancreatic lymphoma with pancreatic cancer or autoimmune pancreatitis (AIP) is still difficult without histologic examination.We report here a rare case of a 71-year-old female with pancreatic follicular lymphoma that initially presented as acute pancreatitis.     

Induction of islet B-cell regeneration in partially pancreatectomized rats by poly(ADP-ribose) synthetase inhibitors

In order to clarify the mechanism of the prevention of diabetes mellitus developing after subtotal pancreatectomy, we examined regenerative activities of islet B-cells in 90% pancreatectomized and poly (ADP-ribose) synthetase inhibitor-treated rats by using autoradiographic and stathmokinetic techniques. Thirty days after 90% pancreatectomy, islets of rats without 3-aminobenzamide treatment were decreased in number, small in size and had irregular contour. Degranulation of the B-cells and fibrotic degeneration were frequently encountered. On the contrary, islets of remaining pancreas in rats receiving 3-aminobenzamide were increased in number, and their diameters ranged from 0.3-0.6 mm, being about two fold larger than those of normal rats. The labeling index of 3H-thymidine autoradiography and the mitotic indices in islet B-cells were increased in a temporally correlated manner in the 3-aminobenzamide treated rats. The mitotic indices of the 3-aminobenzamide-treated group on the 5th, 7th, 10th and 15th days were significantly larger than those in the control group. These results indicate that poly (ADP-ribose) synthetase inhibitors can induce self-replication or regeneration of B-cells in partially pancreatectomized rats.     

Cicatricial Pemphigoid of the Oropharynx after Allogeneic Stem Cell Transplantation for Relapsed Follicular Lymphoma

A 44-year-old woman with refractory follicular lymphoma underwent allogeneic stem cell transplantation (SCT) and achieved complete remission. Grade III acute graft-versus-host disease (GVHD) developed on day 23, but no chronic GVHD occurred. The patient developed severe erosion with bullous lesions in the oral cavity 18 months after SCT. At that time, the lymphoma remained in complete remission, and she had no clinical or laboratory findings suggesting chronic GVHD. A biopsy of the oral mucosa showed moderate lymphoplasmacytic infiltration and subepidermal bullae, and direct immunofluorescence staining demonstrated linear deposition of C3 at the dermo-epidermal junction. An immunoblotting assay using human epidermal extracts confirmed the presence in her serum of an antibody against the 230-kd bullous pemphigoid antigen 1 (BPAG1). A diagnosis of cicatricial pemphigoid (CP) was made, and complete resolution of the CP was achieved with pred-nisolone therapy. The occurrence of autoimmune blistering diseases is rare after allogeneic SCT.