Rearrangement of immunoglobulin light chain genes in the chicken occurs prior to colonization of the embryonic bursa of Fabricius.

We have applied polymerase-chain-reaction-directed immunoglobulin gene analysis to study the embryonic differentiation of chicken B cells. Immunoglobulin light chain DNA segments in the rearranged configuration were amplified from cells of the intraembryonic mesenchyme as early as day 7 of incubation. We showed by sequencing that the rearranged variable region genes in these early B-cell progenitors were not different from the germ-line V lambda 1 gene (the single functional light chain variable region gene in chickens). In the bursal B lymphocytes, on the other hand, clear gene conversion events were first observed at day 15 of embryonic development. The present data indicate that rearrangement of light chain genes in the chicken occurs independently of the bursa of Fabricius and that diversification of the variable region begins only later, when the surface immunoglobulin-positive B cells are proliferating in the bursal follicles.     

Successful Liver-Kidney Transplantation in Two Children With aHUS Caused by a Mutation in Complement Factor H

A 12-month-old boy and his 16-year-old aunt became acutely ill 6 months apart and were diagnosed to have atypical hemolytic uremic syndrome (aHUS). Genetic analysis revealed heterozygous R1215Q mutation in complement factor H (CFH) in both patients. The same mutation was found in five healthy adult relatives indicating incomplete penetrance of the disease. The patients developed terminal renal failure and experienced reversible neurological symptoms in spite of plasma exchange (PE) therapy. In both cases, liver-kidney transplantation was successfully performed 6 months after the onset of the disease. To minimize complement activation and prevent thrombotic microangiopathy or overt thrombotic events due to the malfunctioning CFH, extensive PE with fresh frozen plasma was performed pre- and perioperatively and anticoagulation was started a few hours after the operation. No circulatory complications appeared and all four grafts started to function immediately. Also, no recurrence or other major clinical setbacks have appeared during the postoperative follow-up (15 and 9 months) and the grafts show excellent function. While more experience is needed, it seems that liver-kidney transplantation combined with pre- and perioperative PE is a rational option in the management of patients with aHUS caused by CFH mutation.     

Outcome of patients with dual diagnosis in secondary psychiatric care

Background: Dual diagnosis (DD) is a common co-morbidity of mental illness and substance use disorder (SUD) and patients with DD are prone to complications. Better knowledge on the outcome, mortality and management of patients with DD in usual secondary psychiatric care would help to inform improved treatment strategies in the future. Aims: To explore the functional outcome and mortality of patients with DD receiving psychiatric treatment. To assess the recognition of substance use disorders (SUDs) in terms of diagnosis, and the associations of clinically diagnosed SUDs with treatment-related variables. Methods: The sample of 330 patients was collected by screening all currently treated patients with the Alcohol Use Disorders Identification Test (AUDIT) and a question about other substances used. The inclusion criteria were AUDIT?>7 and/or reported use of other substances during the preceding 12 months. The Global Assessment of Functioning scale was used to assess functional outcomes during a 2-year follow-up. Information concerning treatment and patient characteristics was collected retrospectively. Results: Level of functioning remained stable among all study patients during follow-up. The mortality rate was not increased. Effective medication use was associated with improved functional outcomes. SUDs were underdiagnosed. A clinically diagnosed SUD seemed to have an impact on the regularity of appointments and the doses of prescribed medications. Conclusions: Given our results suggesting a stable level of functioning, patients with DD appear to be well managed within secondary psychiatric care. Attention should be paid to more precise diagnostics of SUDs and to effective use of medication.     

Studies of adhesion-dependent platelet activation: distinct roles for different participating receptors can be dissociated by proteolysis of collagen

The molecular differences between native-type collagen type I fibrils (NC) and their pepsinated monomers (PC) were used to uncover receptors involved in platelet-collagen interaction along the adhesion-activation axis. The platelet-depositing capacity of NC and PC under blood flow and their adhesive properties and respective morphologies, aggregation, procoagulant capacity, and tyrosine phosphorylation were compared under different cationic milieus, including or excluding the glycoprotein (GP) Ia/IIa. NC was consistently a more preferable and activating substrate than PC during flow (5 minutes) and in platelet aggregation. In PPACK-treated blood, both NC (3.3-fold) and PC (2.7-fold) increased platelet attachment on elevation of the shear rate from 500 to 1640 s(-1), whereas in citrated blood, adhesion and thrombus growth on PC were negligible under the high shear rate, unlike on NC (1.9-fold increase). The complete lack of platelet deposition on PC in citrated blood could be overcome by restoring physiological Mg(2+) concentration, and in contrast to NC, platelets interacting with PC were highly dependent on Mg(2+) during adhesion, aggregation, and procoagulant response. Monoclonal antibody (mAb 131.7) against GP IV inhibited platelet deposition to NC in citrated blood (2 minutes) by 49%, which was not further increased by coincubation with mAb against GP Ia (6F1). These results stress the importance of GP Ia/IIa in shear-resistant platelet deposition on collagen monomers. In native fibers, however, the preserved quaternary structure with telopeptides activates additional platelet receptors capable of substituting GP Ia/IIa and GP IV.     

Acid α-naphthyl Acetate Esterase Activity in Nucleated Red Cells of Human Fetal Liver

Acid α-naphthyl acetate esterase (ANAE) activity was investigated in nucleated red cells obtained from nine human fetal livers at 9-24 weeks of gestation. A strong ANAE activity was demonstrated in fetal liver erythroblasts with a staining pattern of a perinuclear ring. Occasionally some polychromato-philic normoblasts expressed a focal ANAE activity usually observed in human T-lymphocytes. Some 50-70% of erythroblasts in human fetal livers showed a ring-like staining pattern. A slight decrease of ANAE positivity was observed in cells of fetal livers after 17 weeks of gestation.     

In vitro fracture resistance of fiber reinforced cusp-replacing composite restorations.

OBJECTIVES: To assess the fracture resistance and failure mode of fiber reinforced composite (FRC) cusp-replacing restorations in premolars. METHODS: Forty-five extracted sound upper premolars were randomly divided into three groups. Identical MOD cavities with simulated buccal cusp fracture and height reduction of the palatal cusp were prepared. In Group A two layers of resin impregnated woven continuous FRC (EverStick Net) were applied. In Group B one layer of unidirectional continuous FRC (EverStick) was used. In Group C no fibers were applied (control). Subsequently, all teeth were restored with resin composite (Clearfil Photo Posterior), subjected to thermocycling (6000 x 5-55 degrees C) and static load tests. Load until fracture was registered for each tooth. Simultaneously, fracture propagation was monitored using acoustic emission analysis (AE). Failure modes were visually assessed. RESULTS: Weibull analysis revealed a characteristic strength and Weibull modulus (m) at 2364.8 N for Group A (m=8.9), 2437.9 N for Group B (m=5.9) and 2160.3N for Group C (m=13.6). Fracture loads were not significantly different (ANOVA, p>0.05). Teeth with FRC showed less fractures below the cemento-enamel junction (CEJ) (38% and 23% for Groups A and B, respectively) than teeth without FRC (93%) (chi-square, p<0.05). The control group showed the least AE energy signals. SIGNIFICANCE: The results suggest that glass FRC does not increase fracture load of premolars with cusp-replacing restorations. However, FRC has a beneficial effect on the failure mode. Woven fibers give more consistent results than unidirectional fibers.     

Antiplatelet effect of clopidogrel in patients with aspirin therapy undergoing percutaneous coronary interventions – Limited inhibition of the P2Y12 receptor

IntroductionLarge individual variability in clopidogrel responses has been reported. However, mechanisms of the non-responsiveness are unclear. Our aim was to study the extent of platelet inhibition at the receptor level by in vitro receptor antagonists of P2Y₁₂ (AR-C69931MX, cangrelor) and P2Y₁ (adenosine 3’,5’diphosphate) in aspirin treated patients with coronary artery disease (CAD) prior to and after in vivo clopidogrel.Materials and Methods51 aspirin-treated (100 mg/day) patients participated. Blood was collected before and after administration of clopidogrel at 300 mg loading dose on day one, followed by 75 mg/d for four days. Aggregation in platelet-rich plasma was assessed.ResultsIn 20% of patients clopidogrel failed to inhibit platelet responses to ADP. These non-responders had also decreased sensitivity to an in vitro P2Y₁₂-receptor antagonist compared with the responders (mean inhibition of aggregation 25 vs. 32%, difference of means 7% (95% CI 2-12%), P < 0.02). Moreover, the P2Y₁₂-receptor inhibition by in vivo clopidogrel correlated with the inhibition by in vitro ARMX measured prior to administration of clopidogrel. Neither P2Y₁-receptor activity, thrombin generation while on aspirin nor basal platelet activity associated with clopidogrel responses.ConclusionsConcomitant aspirin and clopidogrel treatment failed to suppress platelet activity in 20% of patients. Non-responders to clopidogrel had decreased responses also to another ADP receptor antagonist, which suggests that the impaired response occurs at the level of P2Y₁₂-receptor.