Reconstruction of extensive tissue defects of the scalp by microsurgical composite tissue transplantation.

Two cases of severe and extensive electrical burns of the scalp and skull are presented. Large segments of composite groin tissue were successfully transplanted to cover the scalp defects. Microvascular surgical techniques were employed. Both patients had short postoperative hospitalizations. It is possible that a cranioplasty may now be performed as a second stage under the healed full-thickness skin. The advantages of providing a thick protective skin cover in a single operation are outlined.     

Arterial anastomoses and autogenous interposition grafts in growing rats

The fate of arterial interposition grafts in growing rats was investigated. The interrupted- and continuous-suture techniques were compared to see which allowed for better expansion of the anastomosis. We found that a graft enlarges in proportion to the growth of the parent vessel, that in end-to-end anastomosis the interrupted suture technique allowed for better expansion of the anastomosis (but not in the end-to-side model), and that the continous suture technique was associated with a higher rate of false aneurysm formation.     

The Role of Membrane Bound Complement in the Aggregation of Mammalian Platelets by Collagen

Platelets from dogs decomplemented with purified Cobra Venom Factor (CVF) lose the ability to aggregate in response to collagen stimulation. In vitro in man, dog and rabbit, and in vivo in the dog, CVF abolishes the collagen response of platelets, the effect being dose-related. Resuspension of CVF inactivated platelets in plasma containing complement resulted in a total return of sensitivity to collagen. Examination of CVF inactivated platelets with the electron microscope failed to show any marked difference from control platelets. Serotonin granules were still present and the platelets retained a discoid appearance. Incubation of platelets with antibodies to C1, C3 and C5 resulted in inhibition of the collagen response: this effect was dose-related. Light microscopy indicated that DVF does not affect the adhesion of platelets to collagen but appears to prevent subsequent aggregation. It is suggested that the complement system is involved in the induction of the platelet release reaction by collagen, and that inhibition by CVF and anticomplement antibodies is the result of a blocking of the release reaction.     

Preparative purification of the rat mast cell chymase. Characterization and Interaction with granule components

The rat mast cell granule chymotrypsinlike enzyme was purified to homogeneity from 1 M NaCl solubilized membrane and granule-rich fractions of concentrated rat peritoneal mast cells by a preparative technique utilizing chromatography on Dowex 1, filtration on Sephadex G-75, and affinity chromatography with D-tryptophan methyl ester. Acid disk gel electrophoresis of the purified chymase disclosed a single stained band with activity being eluted from a replicate sliced gel in the same region. SDS-polyacrylamide gel electrophoresis of purified protein gave a single stained band that did not change in position with reduction and alkylation. Mast cell chymase is thus a cationic protein of 25,000 mol wt composed of a single polypeptide chain. The apparent K(m) of the chymase for BTEE was 1.5 x 10(-3) M and the V(max) was 67.8 μmol/min per mg. The enzyme was inhibited by TPCK and not by TLCK. The chymase complexed with native macromolecular rat mast cell heparin in molar ratios of 12:1 and 16:1, and complete heparin uptake occurred at a 40:1 ratio of chymase to heparin. Chymase activity was partially masked by combination with heparin in the isolated granule or experimental chymase-heparin complex, and soluble purified chymase was inhibited by concentrations of 5-HT comparable to those present in mast cells. It is therefore possible that the active site of chymase in the mast cell granule is largely masked by the combined effects of macromolecular heparin and 5-HT.     

Identifying Optimum Performance Trade‐Offs Using a Cognitively Bounded Rational Analysis Model of Discretionary Task Interleaving

We report the results of a dual‐task study in which participants performed a tracking and typing task under various experimental conditions. An objective payoff function was used to provide explicit feedback on how participants should trade off performance between the tasks. Results show that participants’ dual‐task interleaving strategy was sensitive to changes in the difficulty of the tracking task and resulted in differences in overall task performance. To test the hypothesis that people select strategies that maximize payoff, a Cognitively Bounded Rational Analysis model was developed. This analysis evaluated a variety of dual‐task interleaving strategies to identify the optimal strategy for maximizing payoff in each condition. The model predicts that the region of optimum performance is different between experimental conditions. The correspondence between human data and the prediction of the optimal strategy is found to be remarkably high across a number of performance measures. This suggests that participants were honing their behavior to maximize payoff. Limitations are discussed.     

Adherence to secondary prophylaxis and disease recurrence in 536 Brazilian children with rheumatic fever

Background  

More than 15 million people worldwide have rheumatic fever (RF) and rheumatic heart disease due to RF. Secondary prophylaxis is a critical cost-effective intervention for preventing morbidity and mortality related to RF. Ensuring adequate adherence to secondary prophylaxis for RF is a challenging task. This study aimed to describe the rates of recurrent episodes of RF, quantify adherence to secondary prophylaxis, and examine the effects of medication adherence to the rates of RF in a cohort of Brazilian children and adolescents with RF.     

Expression of galectin-3 and its regulation in the testes

Although spermatogenesis is a complex process under hormonal control, which includes mainly follicle stimulating hormone (FSH) and androgens, little is known about the intra-testicular mediators of these hormones. In the present study, galectin-3 (Gal-3) expression has been identified in human, rat and porcine testes where it is under hormonal control. Gal-3 is present in Sertoli cells and appears to be absent in human and (probably) in rat germ cells. Gal-3 expression was evidenced in the testes, in terms of both mRNA and protein (31 kDa). Gal-3 expression in cultured porcine Sertoli cells was shown to be under the positive control of FSH as well as of two cytokines epidermal growth factor (EGF) and tumour necrosis factor-alpha (TNF-alpha). Gal-3 expression in Sertoli cells is also potentially under the control of mature germ cells as an increased expression was observed in adult rat testes depleted in spermatocytes or spermatids. Although the function of testicular Gal-3 remains to be investigated, a potential role of Gal-3 in germ cell survival/regeneration is suggested based on its increased expression 1 month after a transient germ cell death process triggered by 10 days of treatment with the antiandrogen flutamide. Finally, although in the normal human testes, Gal-3 is exclusively located in the Sertoli cell cytoplasm, a nuclear localization is observed in the infertile testes. Together, the present findings have shown that (i) Gal-3 is expressed in the porcine, rat and human Sertoli cells; (ii) Gal-3 is under the positive control of FSH as well as of EGF and TNF-alpha and possibly of adult germ cells. These observations are compatible with a potential pro-survival role of Gal-3 in the testes.     

The management of familial hypercholesterolaemia in Morocco

Familial hypercholesterolaemia (FH) is an autosomal dominant disorder characterized by high levels of low-density lipoprotein cholesterol (LDL-C) as a result of mutations that impair their removal from plasma.The clinical consequence is a high risk of premature cardiovascular disease. Because of the extreme risk of mortality and morbidity, diagnosis, recruitment and management of FH patients must be one of the priorities of public health. In Morocco, specialized consultation for dyslipidaemia and strategy for management of this cardiovascular major risk factor does not exist, making FH identification and management difficult. In this review, we present the first FH state of the art in our country through a sample of 66 subjects. By this analysis, we have tried to elucidate some points that impede the identification and recruitment of heterozygous FH and the management of both heterozygous and homozygous FH in Morocco. Also, we have attempted to propose some strategies for an adequate management of FH in our country, taking into account the local specifications.