Quantification of angiogenesis in estrogen receptor-positive and negative breast carcinoma

Background

The objective of this study was to evaluate angiogenesis according to CD34 antigen expression in estrogen receptor (ER)-positive and negative breast carcinomas.

Methods

This study comprised 64 cases of infiltrating ductal carcinoma in postmenopausal women divided into two groups: Group A: ER-positive, n = 35; and Group B: ER-negative, n = 29. The anti-CD34 monoclonal antibody was used as a marker for endothelial cells. Microvessel count was carried out in 10 fields per slide using a 40× objective lens (magnification 400×). Statistical analysis of the data was performed using Student's t-test (p < 0.05).

Results

The mean number of vessels stained with the anti-CD34 antibody in the estrogen receptor-positive and negative tumors was 23.51 ± 1.15 and 40.24 ± 0.42, respectively. The number of microvessels was significantly greater in the estrogen receptor-negative tumors (p < 0.001).

Conclusion

ER-negative tumors have significantly greater CD34 antigen expression compared to ER-positive tumors.

     

Differential responsiveness to immunoablative therapy in refractory rheumatoid arthritis is associated with level and avidity of anti-cyclic citrullinated protein autoantibodies: a case study

In order to identify pathogenic correlates of refractory rheumatoid arthritis (RA), antibodies against anti-cyclic citrullinated protein (ACPAs) were investigated in RA patients in whom the dysregulated immune system had been ablated by high-dose chemotherapy (HDC) and autologous haematopoietic stem cell transplantation (HSCT). Six patients with refractory RA were extensively characterized in terms of levels of total immunoglobulins, RA-specific autoantibodies (ACPAs and rheumatoid factor) and antibodies against rubella, tetanus toxoid (TT) and phosphorylcholine before and after HDC plus HSCT. Additionally, the avidity of ACPAs was measured before and after treatment and compared with the avidity of TT antibodies following repeated immunizations. Synovial biopsies were obtained by arthroscopy before HDC plus HSCT, and analyzed by immunohistochemistry. In the three patients with clinically long-lasting responses to HDC plus HSCT (median 423 days), significant reductions in ACPA-IgG levels after therapy were observed (median level dropped from 215 to 34 arbitrary units/ml; P = 0.05). In contrast, stable ACPA-IgG levels were observed in three patients who relapsed shortly after HDC plus HSCT (median of 67 days). Clinical responders had ACPA-IgG of lower avidity (r = 0.75; P = 0.08) and higher degree of inflammation histologically (r = 0.73; P = 0.09). Relapse (after 38 to 530 days) in all patients was preceded by rising levels of low avidity ACPA-IgG (after 30 to 388 days), in contrast to the stable titres of high avidity TT antibodies. In conclusion, humoral autoimmune responses were differentially modulated by immunoablative therapy in patients with synovial inflammation and low avidity ACPA-IgG autoantibodies as compared with patients with high levels of high avidity ACPA-IgG. The distinct clinical disease course after immunoablative therapy based on levels and avidity of ACPA-IgG indicates that refractory RA is not a single disease entity.     

Exploration of the structure-activity relationship of the diaryl anilide class of ligands for translocator protein-potential novel positron emitting tomography imaging agents

A series of novel ligands based on the diaryl anilide (DAA) class of translocator protein (TSPO) ligands was synthesised and evaluated as potential positron emitting tomography (PET) ligands for imaging TPSO in vivo. Fluorine-18 labelling of the molecules was achieved using direct radiolabelling or synthon based labelling approaches. Several of the ligands prepared have promising profiles as potential TSPO PET imaging ligands and will be evaluated further as potential clinical imaging agents.     

Isolation of proteinase K-sensitive prions using pronase E and phosphotungstic acid

Disease-related prion protein, PrP(Sc), is classically distinguished from its normal cellular precursor, PrP(C), by its detergent insolubility and partial resistance to proteolysis. Molecular diagnosis of prion disease typically relies upon detection of protease-resistant fragments of PrP(Sc) using proteinase K, however it is now apparent that the majority of disease-related PrP and indeed prion infectivity may be destroyed by this treatment. Here we report that digestion of RML prion-infected mouse brain with pronase E, followed by precipitation with sodium phosphotungstic acid, eliminates the large majority of brain proteins, including PrP(C), while preserving >70% of infectious prion titre. This procedure now allows characterization of proteinase K-sensitive prions and investigation of their clinical relevance in human and animal prion disease without being confounded by contaminating PrP(C).     

Functional genomics of the yeast DNA-damage response

High-throughput approaches are beginning to have an impact on many areas of yeast biology. Two recent studies, using different experimental platforms, provide insight into new pathways involved in the response of yeast to DNA damage.     

SV40 VP2 and VP3 insertion into ER membranes is controlled by the capsid protein VP1: implications for DNA translocation out of the ER

Nonenveloped viruses such as Simian Virus 40 (SV40) exploit established cellular pathways for internalization and transport to their site of penetration. By analyzing mutant SV40 genomes that do not express VP2 or VP3, we found that these structural proteins perform essential functions that are regulated by VP1. VP2 significantly enhanced SV40 particle association with the host cell, while VP3 functioned downstream. VP2 and VP3 both integrated posttranslationally into the endoplasmic reticulum (ER) membrane. Association with VP1 pentamers prevented their ER membrane integration, indicating that VP1 controls the function of VP2 and VP3 by directing their localization between the particle and the ER membrane. These findings suggest a model in which VP2 aids in cell binding. After capsid disassembly within the ER lumen, VP3, and perhaps VP2, oligomerizes and integrates into the ER membrane, potentially creating a viroporin that aids in viral DNA transport out of the ER.     

Strain-specific prion-protein conformation determined by metal ions

In animals infected with a transmissible spongiform encephalopathy, or prion disease, conformational isomers (known as PrPSc proteins) of the wild-type, host-encoded cellular prion protein (PrPc) accumulate. The infectious agents, prions, are composed mainly of these conformational isomers, with distinct prion isolates or strains being associated with different PrPSc conformations and patterns of glycosylation. Here we show that two different human PrPSc types, seen in clinically distinct subtypes of classical Creutzfeldt-Jakob disease, can be interconverted in vitro by altering their metal-ion occupancy. The dependence of PrPSc conformation on the binding of copper and zinc represents a new mechanism for post-translational modification of PrP and for the generation of multiple prion strains, with widespread implications for both the molecular classification and the pathogenesis of prion diseases in humans and animals.