Effects of phosphatidylserine coatings on titanium on inflammatory cells and cell-induced mineralisation in vitro

Ideally an active bone biomaterial should increase the mineralisation rate at the bone healing sites, keeping at the same time the inflammation process to levels required for tissue regeneration. Our studies suggest that in addition to improving the nucleation process for new bone formation, coating titanium with phospholipids may reduce the inflammatory response, which was shown to vary depending on the formulation employed. As phosphatidylserine reduced the inflammatory response to the greatest extent, in the second part of this study we examined its effect on osteoblast mineralisation. These studies demonstrated that phosphatidylserine improves the nucleation process for bone formation, by promoting the formation of bone-like tissue, so the high mineralisation potential of phosphatidylserine-coated titanium, together with the lower level of inflammatory response, supports the further development of this technology for coating osteointegrative devices.     

The role of quantitative polymerase chain reaction in the management of follicular lymphoma patients

AIMS AND BACKGROUND: In order to increase the prognostic significance of polymerase chain reaction (PCR) data it has been suggested that quantitative PCR can be used to measure tumor burden. However, this option has not yet been definitely supported or refuted in patients with follicular lymphoma (FL). We decided to evaluate whether knowledge of the quantitative level of minimal residual disease and its variations can be of use in the management of FL patients. METHODS: We used qualitative and competitive PCR to study 11 patients with refractory or relapsed FL harboring the t(14;18) translocation who underwent autologous (nine patients) or allogeneic (two patients) stem cell transplantation (SCT). Competitive PCR was performed with a multiple competitor carrying specific sequences including Bcl2/IgH MBR and mcr, and the beta-globin gene. RESULTS: After a median post-SCT follow-up of 44 months (range, 12-62), overall survival was 91% and disease-free survival 82%. The quantitative PCR data showed that: 1) effective chemotherapy before SCT substantially (1-2 log) reduced the tumor burden in the bone marrow (BM); 2) the increase in rearranged DNA detected in BM was associated with disease progression and relapse; 3) a PCR-negative autograft seemed to lead to lasting molecular remission even when it was performed in patients with a low level of BM infiltration before transplant; and 4) allo-SCT made and maintained the BM PCR negative even in the presence of a greater tumor burden before SCT. Six of the nine patients having CR after SCT (four auto and two allo) are in continuous molecular remission. CONCLUSIONS: In FL patients qualitative and quantitative PCR may provide data that can be helpful for the prognostic evaluation of tumor progression and the early detection of impending relapse by highlighting biological features such as the quality of the infused material, the tumor burden at transplant, and the behavior of tumor cells after transplant.     

Oral pulsatile drug delivery systems

In the field of modified release, there has been a growing interest in pulsatile delivery, which generally refers to the liberation of drugs following a programmable lag phase from the time of administration. In particular, the recent literature reports on a variety of pulsatile release systems intended for the oral route, which have been recognised as potentially beneficial to the chronotherapy of widespread diseases, such as bronchial asthma or angina pectoris, with mainly night or early morning symptoms. In addition, time-dependent colon delivery may also represent an appealing related application. The delayed liberation of orally administered drugs has been achieved through a range of formulation approaches, including single- or multiple-unit systems provided with release-controlling coatings, capsular devices and osmotic pumps. Based on these premises, the aim of this review is to outline the rational and prominent design strategies behind oral pulsatile delivery.     

Segmentary effects on the renal proximal tubule due to hexachloro-1,3-butadiene in rats: biomarkers related to gender

Renal tissue biomarkers (glutamine synthetase and p-aminohippuric acid uptake) were studied in male and female rats after treatment with hexachloro-1,3-butadiene. Reduced glutathione content also was also determined in liver and kidney. Histopathological examination (light microscopy) was then performed. The aim was to define sex differences in nephrotoxic effects caused by the solvent injected i.p. at 50, 100 and 200 mg kg(-1) dose. The rats were sacrificed 24 and 48 h after treatment; after 24 h a significant (P < 0.05) dose-dependent depletion of liver reduced glutathione was observed in male rats only; after 48 h male and female rats showed a significant (P < 0.05) increase at 50 and 100 mg kg(-1) doses. Reduced glutathione in the kidney was increased in male but not in female rats 24 and 48 h after treatment. Glutamine synthetase activity in renal tissue showed a significant (P < 0.05) dose-dependent decrease 24 and 48 h after treatment in both sexes, but is was significantly (P < 0.05) greater in female rats after 48 h. p-Aminohippuric acid uptake in renal cortical slices appeared significantly (P < 0.05) decreased in both sexes at the higher dose 24 h after treatment but this was significantly (P < 0.05) greater in female rats. A further significant (P < 0.05) impairment was observed after 48 h in males treated with a 200 mg kg(-1) dose. In addition, a slight but significant (P < 0.05) loss of p-aminohippuric acid uptake was observed 48 h after treatment with a 100 mg kg(-1) dose in both sexes. Light microscopy showed that the pars recta of the proximal tubule was mainly affected and tubular damage increased according to dose and time, involving the inner medulla and cortex. In conclusion, female rats show a significantly earlier and higher susceptibility of the kidney to toxic effects of hexachloro-1,3-butadiene.     

A miniaturized, optically accessible bioreactor for systematic 3D tissue engineering research

Perfusion bioreactors are widely used in tissue engineering and pharmaceutical research to provide reliable models of tissue growth under controlled conditions. Destructive assays are not able to follow the evolution of the growing tissue on the same construct, so it is necessary to adopt non-destructive analysis. We have developed a miniaturized, optically accessible bioreactor for interstitial perfusion of 3D cell-seeded scaffolds. The scaffold adopted was optically transparent, with highly defined architecture. Computational fluid dynamics (CFD) analysis was useful to predict the flow behavior in the bioreactor scaffold chamber (that was laminar flow, Re = 0.179, with mean velocity equal to 100 microns/s). Moreover, experimental characterization of the bioreactor performance gave that the maximum allowable pressure was 0.06 MPa and allowable flow rate up to 25 ml/min. A method, to estimate quantitatively and non destructively the cell proliferation (from 15 to 43 thousand cells) and tissue growth (from 2% to 43%) during culture time, was introduced and validated. An end point viability test was performed to check the experimental set-up overall suitability for cell culture with successful results. Morphological analysis was performed at the end time point to show the complex tridimensional pattern of the biological tissue growth. Our system, characterized by controlled conditions in a wide range of allowable flow rate and pressure, permits to systematically study the influence of several parameters on engineered tissue growth, using viable staining and a standard fluorescence microscope.     

Human epithelial growth factor receptor 2 (HER2) status in primary and metastatic esophagogastric junction adenocarcinomas

Differences in human epithelial growth factor receptor 2 dysregulation in primary solid tumors and metastases may (at least partially) explain human epithelial growth factor receptor 2-targeted therapeutic inconsistencies. Human epithelial growth factor receptor 2 status was tested in a series of 47 radically treated consecutive esophagogastric junction adenocarcinomas (male/female, 38/9; mean age, 67.9 years) in both primary cancers and paired synchronous nodal metastases. None of the patients received neoadjuvant therapy. For each case, 2 nonadjacent tissue samples from primary esophagogastric junction adenocarcinoma and 2 different metastatic nodes were considered (188 tissue samples in all). Human epithelial growth factor receptor 2 status was assessed by immunohistochemistry (PATHWAY-HER2/neu [4B5]; Ventana Medical Systems, Milan, Italy) and dual chromogenic in situ hybridization (duoCISH; DAKO, Glostrup, Denmark). Immunohistochemistry staining scores were nil in 22 tumors (47%), 1 (21%) in 10, 2 (13%) in 6, and 3 (19%) in 9. Human epithelial growth factor receptor 2 gene amplification (25.5%) was associated with more differentiated phenotype (Fisher exact test, P = .039) and advanced tumor stage (Fisher exact test, P = .015). Significant agreement was observed between human epithelial growth factor receptor 2 protein expression (immunohistochemistry) and human epithelial growth factor receptor 2 gene's amplification (chromogenic in situ hybridization) (κ = 0.84, P < .001). Both immunohistochemistry and chromogenic in situ hybridization documented an excellent intratumor agreement in human epithelial growth factor receptor 2 status (κ = 0.75, P < .001; κ = 0.88, P < .001, respectively). Human epithelial growth factor receptor 2 status was comparable in primary versus metastatic nodal cancers by both immunohistochemistry and chromogenic in situ hybridization (Cohen Φ, both P < .001). In esophagogastric junction adenocarcinomas, human epithelial growth factor receptor 2 status (as assessed by immunohistochemistry and/or chromogenic in situ hybridization) is virtually unaffected by intratumor variability; it is consistent with findings in nodal metastases, and it reliably identifies patients with esophagogastric junction adenocarcinoma eligible for anti-human epithelial growth factor receptor 2 therapy.     

Bleeding from duodenal ulcer in a patient with bilio-pancreatic diversion

Scopinaro’s bilio-pancreatic diversion is considered as an acceptable malabsorptive surgical approach for the treatment of morbid obesity. We describe a case of acute recurrent gastro-intestinal bleeding in a patient with a previous Scopinaro’s bilio-pancreatic diversion. At the first admission in our department, gastroscopy, colonoscopy, contrast-enhanced computerized tomography and angiography resulted negative for active bleeding. Hypovolemic shock indicated laparotomy and an intraoperative enteroscopy performed through a small enterotomy showed an ulcerative perforation sourced in an ischemic portion of a distended duodenal stump, with a bleeding branch of gastro-duodenal artery at the bottom. Hemorrhage was stopped with stitches. Two years later a new episode of duodenal bleeding associated with severe malnutrition occurred. A covered chronic ischemic perforation sustained by duodenal distension due to biliopancreatic limb sub-obstruction appeared to be the most probable etiology of the recurrent duodenal bleeding. The patient underwent again to laparotomy and adhesiolysis; hemorrhage was stopped by means of ligation of gastroduodenal artery and bilio-pancreatic diversion was converted into a standard Roux-en-Y gastroenterostomy with an entero-entero anastomosis 40 cm from the Treitz ligament in order to restore an anatomo-functional condition guaranteeing normal absorption and intestinal transit. After Scopinaro’s bilio-pancreatic diversion duodenal bleeding can represent a rare serious presentation of biliopancreatic limb obstruction; because of the complex anatomical reconstruction performed during this intervention, the duodenum results unavailable during upper gastro-intestinal endoscopy, and if a duodenal bleeding is suspected laparotomy followed by enteroscopy represents an effective diagnostic approach.