Reflection and transmission calculations in a multilayer structure with coherent, incoherent, and partially coherent interference, using the transmission line method.

A generalized transmission line method (TLM) that provides reflection and transmission calculations for a multilayer dielectric structure with coherent, partial coherent, and incoherent layers is presented. The method is deployed on two different application fields. The first application of the method concerns the thickness measurement of the individual layers of an organic light-emitting diode. By using a fitting approach between experimental spectral reflectance measurements and the corresponding TLM calculations, it is shown that the thickness of the films can be estimated. The second application of the TLM concerns the calculation of the external quantum efficiency of an organic photovoltaic with partially coherent rough interfaces between the layers. Numerical results regarding the short circuit photocurrent for different layer thicknesses and rough interfaces are provided and the performance impact of the rough interface is discussed in detail.

VEGF and Id-1 in pancreatic adenocarcinoma: prognostic significance and impact on angiogenesis.

OBJECTIVES: The significance of vascular endothelial growth factor (VEGF) and inhibitor of differentiation/DNA synthesis (Id-1) in tumor neoangiogenesis and tumor progression in pancreatic ductal adenocarcinoma (PDAC) is still unclear. Given the central role of VEGF in cancer angiogenesis and the inconclusive results on Id-1 expression in PDAC, it is of great interest to investigate whether Id-1 and VEGF expression are associated with angiogenesis and prognosis in PDAC. METHODS: Paraffin-embedded specimens from 60 consecutive patients with PDAC were immunostained for VEGF, Id-1 and CD34 and staining quantification was assessed by Image analysis system. The correlations among the expression of individual angiogenic factors and microvessel density (MVD), clinicopathologic features and clinical prognosis were analyzed. RESULTS: Id-1 and VEGF Positive Activity Indices (PAIs) closely correlated with each other. MVD positively correlated with both Id-1 and VEGF expression. More advanced T and N status correlated with more intense expression of Id-1, VEGF and higher MVD. With regard to prognostic significance higher Id-1 PAI (adjusted HR = 1.69, 95%CI: 1.10-2.59, p = 0.017), higher VEGF PAI (adjusted HR = 2.66, 95%CI: 1.09-6.50, p = 0.032), and MVD (adjusted HR = 1.55, 95%CI: 1.27-1.88, p < 0.001) were associated with poorer survival. CONCLUSIONS: VEGF and Id-1 overexpression were found to be associated with high MVD and emerged as adverse prognostic factors in terms of patient survival in PDAC. The potential of selective anti-angiogenic targeting therapy for pancreatic malignancies should prompt further validation of the present findings in studies encompassing larger samples and more elaborate techniques.

Theoretical investigation on the effect of protonation on the absorption and emission spectra of two amine-group-bearing, red "push-pull" emitters, 4-dimethylamino-4'-nitrostilbene and 4-(dicyanomethylene)-2-methyl-6-p-(dimethylamino) styryl-4H-pyran, by DFT and TDDFT calculations.

A theoretical investigation on the electronic structure of 4-dimethylamino-4'-nitrostilbene (DANS), 4-(dicyanomethylene)-2-methyl-6-p-(dimethylamino) styryl-4H-pyran (DCM), and their protonated forms is presented in an effort to rationalize recent experimental results on the tuning of the emitted color of organic light-emitting diodes through photochemically induced protonation. Density functional theory (DFT) and time-dependent density functional theory (TDDFT) calculations have been carried out on the neutral and protonated forms of DANS and DCM, employing both the B3LYP and the CAM-B3LYP functionals. It was found that the CAM-B3LYP functional leads to better agreement than the B3LYP of the calculated with the experimental absorption lambda(max) for DANS, whereas B3LYP is more appropriate than CAM-B3LYP for DCM. The results of the calculations aid in a rationalization of the observed differences of the spectra of DANS and DCM upon protonation, and in particular those differences that make DANS a more attractive system for absorbance and emission tuning.

Drug-induced esophagitis.

Drug-induced esophagitis is being recognized increasingly in the past few years. Since 1970 more than 650 cases have been reported worldwide caused by 30 or more medications. We have reviewed these cases with a view to classifying this disease based on underlying pathological mechanism. Drug-induced esophageal injury tends to occur at the anatomical site of narrowing, with the middle third behind the left atrium predominating (75.6%). The disease is broadly classified into two groups. The first group being transient and self-limiting as exemplified by the tetracycline group induced injury (65.8%). The second is the persistent esophagitis group, often with stricture, with two distinct entities: (i) patients on nonsteroidal anti-inflammatory agents whose injury is aggravated by gastroesophageal reflux (21.8%) (reflux aggravated); and (ii) patients with potasium chloride and quinidine sulphate induced injury (12.4%) (persistent drug injury). Severe esophageal injury has been reported in some women taking biphosphonates as treatment for postmenopausal osteoporosis. Endoscopic findings in such patients with esophageal injury generally suggested a chemical esophagitis, with erosions or ulcerations and exudative inflammation accompanied by thickening of the esophageal wall. Most cases of medication-induced esophageal injury heal without intervention within a few days. Thus, the most important aspect of therapy is to make the correct diagnosis and then to avoid reinjury with the drug. When possible, potentially caustic oral medications should be discontinued.

Spontaneous regression of rectal polyps following abdominal colectomy and ileorectal anastomosis for familial adenomatous polyposis, without sulindac treatment: report of four cases.

The only curative treatment for familial adenomatous polyposis (FAP) is prophylactic surgery and the two most popular options are total colectomy with ileorectal anastomosis and restorative proctocolectomy with ileal pouch-anal anastomosis. Today, ileal pouch-anal anastomosis has gained wider acceptance as a safer procedure, but ileorectal anastomosis still remains an option, especially for young patients with a moderate phenotype of the disease and limited polyps in the rectum. Partial or complete regression of rectal polyps after total colectomy with ileorectal anastomosis and treatment with nonsteroidal anti-inflammatory drugs (NSAIDs) such as sulindac is reported in up to 80 % of patients. However, in some cases such regression can be spontaneous and long-lasting following total colectomy and ileorectal anastomosis, without further treatment with NSAIDs. We present the cases of four patients with FAP treated by colectomy and ileorectal anastomosis, who had immediate, complete spontaneous regression of multiple polyps in the rectal stump, with no further need for sulindac treatment.

Treatment of anemia in low-risk myelodysplastic syndromes with amifostine. In vitro testing of response.

Amifostine (AMF) promotes in vitro growth and survival of hematopoietic progenitors. In this study we evaluated the efficacy of AMF in the treatment of anemia in patients with low-risk myelodysplastic syndromes (MDS) and the possible predicting value for response to AMF therapy of two types of in vitro clonogenic assays. Two different doses of AMF, 300 mg/m2 (group A, 11 patients) or 400 mg/m2 (group B, 16 patients), were studied. AMF was given three times weekly for 3 weeks, i.v., followed by 2 weeks off therapy. Patients were evaluated after two cycles of treatment. Partially or nonresponding patients of group A received 400 mg/m2 AMF and were reevaluated. An increase of hemoglobin (Hb) values of more than 2 g/dl and a 100% decrease in transfusion requirements for at least 6 weeks were defined as a complete response (CR) while an increase of Hb values of 1-2 g/dl or a 50% decrease in transfusion requirements was considered as a partial response (PR). In group A, two out of 11 (18.1%) patients achieved a CR with the initial dose and one of the nine that received 400 mg/m2 AMF achieved a PR. In group B, three out of 16 (18.7%) patients achieved a PR; the overall response rate in both groups was 22.2%. In group A, bone marrow progenitor assay was performed pre- and post-amifostine treatment. Erythroid burst-forming units (BFU-E) were increased in six out of 11 (54.5%) patients, and this increase preceded the rise in Hb levels in three of them. In group B, a clonogenic assay was performed in 11 out of 16 patients before AMF treatment. In vitro results after pretreatment with 500 microM amifostine confirmed the response of two MDS patients that achieved a PR. No response in vitro was observed in all eight nonresponding patients and in one PR patient. The lack of response in the clonogenic assays predicted for nonresponse to treatment with a predictive power of 91.8%. We conclude that 300 mg/m2 is an adequate initial treatment for low-risk MDS patients and both clonogenic assays have a strong predicting value for response to treatment.

A complex pattern of antigen receptor gene rearrangements in a case of Philadelphia positive acute lymphoblastic leukaemia.

The paper describes a case of Philadelphia (Ph) positive acute lymphoblastic leukaemia (ALL) presenting with high white cell count and central nervous system involvement. Immunophenotypically the case was characterized as common ALL. The t(9;22) abnormality corresponded to a rearrangement within the breakpoint cluster region gene, while antigen receptor gene studies showed multiple rearrangements of the immunoglobulin heavy chain gene (IGH) concomitant with a single rearrangement of the T cell receptor beta chain gene (TCR beta). We speculate that this case represents the neoplastic transformation of a stem cell, the Ph abnormality being involved in the early steps of transformation. It is conceivable that the IGH but not the TCR beta gene was accessible to recombination within the malignant clone, thus generating the multiple rearrangements observed. If this is the case, these findings would appear to be compatible with the hypothesis that antigen receptor gene rearrangements may be partly dependent on the accessibility of the corresponding genetic loci.

Alpha-chain disease with clinical, immunological, and histological recovery.

Clinical, immunological, and histological recovery in a patient with alpha-chain disease is described. The patient, a 27-year-old Greek man, presented with severe steatorrhoea, abdominal pain, oedema, and hypogammaglobulinaemia. Treatment with tetracycline produced only temporary remission. Intermittent therapy with prednisone and cyclophosphamide together with antibiotics was followed by clinical recovery, return of histological appearances of the small intestine to normal, and disappearance of free alpha-chain protein from the serum. The patient remained well one year later without treatment.