The blood clotting Factor XIIIa forms unique complexes with amyloid-beta (Aß) and colocalizes with deposited Aß in cerebral amyloid angiopathy.

AIMS: Cerebral amyloid angiopathy (CAA) is a key pathological hallmark of Alzheimer's disease (AD) characterized by accumulation of amyloid-beta (Aß) protein in blood vessel walls. CAA impairs vessel functioning, affects blood brain barrier integrity and accelerates cognitive decline of AD patients. Unfortunately, mechanisms underlying Aß deposition in the vessel wall remain largely unknown. Factor XIIIa (FXIIIa) is a blood-derived transglutaminase crucial in blood coagulation by cross-linking fibrin molecules. Evidence is mounting that blood-derived factors are present in CAA and may play a role in protein deposition in the vessel wall. We therefore investigated whether FXIIIa is present in CAA and if FXIIIa cross-link activity affects Aß aggregation. METHODS: Using immunohistochemistry, we investigated the distribution of FXIIIa, its activator thrombin and in situ FXIIIa activity in CAA in post-mortem AD tissue. We used surface plasmon resonance and Western blot analysis to study binding of FXIIIa to Aß and the formation of FXIIIa-Aß complexes, respectively. In addition, we studied cytotoxicity of FXIIIa-Aß complexes to cerebrovascular cells. RESULTS: FXIIIa, thrombin and in situ FXIIIa activity colocalize with the Aß deposition in CAA. Furthermore, FXIIIa binds to Aß with a higher binding affinity for Aß1-42 compared with Aß1-40 . Moreover, highly stable FXIIIa-Aß complexes are formed independently of FXIIIa cross-linking activity that protected cerebrovascular cells from Aß-induced toxicity in vitro. CONCLUSIONS: Our data showed that FXIIIa colocalizes with Aß in CAA and that FXIIIa forms unique protein complexes with Aß that might play an important role in Aß deposition and persistence in the vessel wall.

Evidence of horsemanship and dogmanship and their application in veterinary contexts.

This review collates peer-reviewed evidence for desirable attributes for those who work with dogs and horses. It is written with a particular focus on the veterinary profession. Although veterinarians and veterinary nurses (VNs) occupy variable roles when interacting with their patients, several behavioural attributes emerge as helpful across the range of such roles. In light of recent research on the value of considering animals' arousal and affective state as predictors of behaviour and welfare, best practice in human-horse and human-dog-interactions is outlined. The attributes of affiliation, safety and positive reinforcement seem to contribute greatly to the development and maintenance of moderate arousal and positive affect in animals. The information in this review article is offered in an attempt to show why veterinary professionals with good horsemanship are likely to remain safe, and to introduce the concept of dogmanship. In the light of the peer-reviewed evidence assembled here, it is arguable that veterinary teams, comprising both veterinarians and VNs, can become scholars in these areas. The benefits of this approach for practitioner safety, animal welfare and client satisfaction are likely to be significant.

The impact of blood glucose and HbA(1c) goals on glycaemic control in children and adolescents with Type 1 diabetes.

AIMS: To evaluate parents' goals and parents' perceptions of physicians' goals for blood glucose and HbA(1c) in children and adolescents with Type 1 diabetes. METHODS: In a cross-sectional observational assessment, parents (80% mothers) of 153 children/adolescents (56% female), aged 12.9 ± 2.3 years (range 8-16 years) with Type 1 diabetes for 6.3 ± 3.5 years, completed surveys regarding their goals and their perceptions of physicians' goals for their child's blood glucose and HbA(1c) levels. RESULTS: Children/adolescents had a mean HbA(1c) of 69 ± 16 mmol/mol (8.4 ± 1.4%) and checked blood glucose levels 3.8 ± 1.2 times/day; 23% received pump therapy. Almost half of parents reported a blood glucose goal of 130 (80-180) mg/dl [7.2 (4.4-10) mmol/l]; 75% of parents reported a HbA(1c) goal of 42-64 mmol/mol (6-8%). HbA(1c) was significantly lower when parents reported HbA(1c) goals ≤ 64 mmol/mol (≤ 8%) vs. > 64 mmol/mol (> 8%) [67 ± 14 mmol/mol (8.3 ± 1.2%) vs. 76 ± 20 mmol/mol (9.1 ± 1.8%), respectively, P = 0.02]. Parents' blood glucose and HbA(1c) goals were tightly linked with parents' perceptions of physicians' blood glucose and HbA(1c) goals (69% concordant, P < 0.0001; 88% concordant, P < 0.0001, respectively). CONCLUSIONS: There was a significant association between lower parent HbA(1c) goals and lower child/adolescent HbA(1c) . Further, parents appear to set glycaemic goals based upon their perceptions of physician goals. Future studies should assess the relationship between parents' perceptions of health-care providers' goals and health-care providers' actual goals and the impact of unified family/provider goal-setting on glycaemic control.

HLA-G protein expression as a potential immune escape mechanism in classical Hodgkin's lymphoma.

Classical Hodgkin's lymphoma (cHL) is characterized by the presence of an abundant reactive infiltrate, lacking effective cytotoxic responses. Especially in Epstein-Barr virus (EBV)-negative cHL, the neoplastic Hodgkin-Reed-Sternberg (HRS) cells have lost protein expression of major histocompatibility complex (MHC) class I, enabling escape from cytotoxic T lymphocyte (CTL) responses. However, downregulation of MHC class I generally induces natural killer (NK) cell activation. The paucity of NK cells in the reactive infiltrate of cHL and the systemic NK cell deficiency observed in cHL patients led us to investigate the expression of human leukocyte antigen (HLA)-G, which is known to inhibit NK-cell- and CTL-mediated cytotoxicity. By immunohistochemistry, HLA-G protein was expressed by HRS cells in 54% (95/175) of cHL cases. This expression was associated with absence of MHC class I on the cell surface of HRS cells (P < 0.001) and EBV-negative status (P < 0.001). Previously, genetic markers located in the proximity of the HLA-A and HLA-G genes had been shown to be associated with susceptibility to EBV-positive cHL. In the present study, these markers associated with MHC class I protein expression but not with presence of HLA-G. Our results suggest that induction of HLA-G protein expression in HRS cells contributes to the modulation of immune responses observed in cHL.

Preservation of bile ductules mitigates bile duct loss.

The finer branches of the biliary tree (FBBT) contain a regenerative compartment. We hypothesized that preservation of the FBBT together with its microvasculature will lead to recovery of biliary damage and prolonged preservation of bile ductules during the development of chronic liver allograft rejection. The interlobular bile ducts, portal bile ductules and extraportal biliary cells with and without microvessels were studied in sequential biopsies in five patients who fulfilled the Banff criteria of early chronic rejection (CR) (imminence group). Biopsies of CR patients (n = 12) served as controls. Biopsies were double immunostained with CD34 (microvessels) and cytokeratin 7 (biliary structures). Proliferation and proangiogenic activity were assessed with Ki67 and VEGF-A immunostaining. Severe damage of bile ducts in the imminence group did not progress to significant bile duct loss. This was associated with a high proliferative activity in all biliary structures and preservation of the microvascular compartment. VEGF-A expression was increased in all but the reperfusion biopsies. In conclusion, both regenerative activity of the FBBT and an intact microvascular compartment are associated with less damage of the biliary tree and could therefore be prerequisites for biliary regeneration.

High expression of Mcl-1 in ALK positive and negative anaplastic large cell lymphoma.

AIM: To gain more insight into the genes involved in the aetiology and pathogenesis of anaplastic large cell lymphoma (ALCL). METHODS: Serial analysis of gene expression (SAGE) was undertaken on the CD4+ALK+ (anaplastic lymphoma kinase positive) ALCL derived cell line Karpas299 and as comparison on CD4+ T cells. Quantitative reverse transcription polymerase chain reaction (RT-PCR) and immunohistochemistry were performed on five ALCL derived cell lines and 32 tissue samples to confirm the SAGE data. RESULTS: High expression of Mcl-1 was seen in the Karpas299 cell line, whereas the two other antiapoptotic Bcl-2 family members, Bcl-2 and Bcl-X(L), were not detected in the SAGE library. Quantitative RT-PCR confirmed the high expression of Mcl-1 mRNA and low expression of Bcl-2 and Bcl-X(L) in Karpas299 and in four other ALCL cell lines. To expand on these initial observations, primary tissue samples were analysed for Mcl-1, Bcl-X(L), and Bcl-2 by immunohistochemistry. All 23 ALK+ and nine ALK- ALCL cases were positive for Mcl-1. Bcl-2 and Bcl-X(L) were expressed infrequently in ALK+ ALCL cases, but were present in a higher proportion of ALK- ALCL cases. CONCLUSION: The consistent high expression of Mcl-1 in ALK+ and ALK- ALCL suggests that Mcl-1 is the main antiapoptotic protein in this disease. The high frequency of Mcl-1, Bcl-2, and Bcl-X(L) positive ALCL cases in the ALK- group compared with the ALK+ group indicates that ALK induced STAT3 activation is not the main regulatory pathway in ALCL.

The stress kit: a new method based on competitive reverse transcriptase-polymerase chain reaction to quantify the expression of human alphaB-crystallin, Hsp27, and Hsp60.

We describe a reverse transcriptase-polymerase chain reaction method for the semiquantitative detection of mRNAs encoding the human heat shock proteins alphaB-crystallin, Hsp27, and Hsp60. The method involves the coamplification of cellular mRNA-derived cDNA with a dilution series of a competitor fragment (internal standard), using 1 primer pair common to both templates. Internal standards were based on cellular-derived cDNA engineered to be slightly smaller to differentiate between the target and the standard on electrophoretic separation. Initial cDNA quantitations can be corrected for possible variations during cDNA synthesis by standardizing to the levels of beta-actin-encoding cDNA. We show that the coamplified templates accumulate in a parallel manner with the cellular-derived cDNA throughout both the exponential and the nonexponential phase of amplification. Furthermore, we illustrate the utility of this technique by quantifying increased expression of alphaB-crystallin, Hsp27, and Hsp60 mRNA in astroglioma cells on heat shock.