Stimulation of brain lipase activity by polyamines. Comparison with the effect of ACTH

Polyamines, as well as ACTH, strongly stimulate at pH 5.75 triacylglycerol lipase (TAGL) activity from rat brain. Whether the activating potency is expressed in terms of molar concentration or amount of positive charges, polyarginine, polylysine, spermine and spermidine exhibit, in this order, decreasing potencies. By contrast to other lipases, heparin (25 micrograms/ml) inhibits brain TAGL. Polyarginine, polylysine and spermine reverse the heparin-dependent inhibition and further stimulate TAGL activity above basal values; spermidine is much less potent. In the presence of heparin, ACTH has the greatest stimulating effect, being 1.6-fold and 3.3-fold more potent than polyarginine and polylysine, respectively. Taken together, the data suggest that polybasic effectors modify the interaction of TAGL with its substrate, resulting in increased levels of TAGL activity. In the presence of heparin, the enzyme charge density is mandatory for determining the stimulation process. Such cationic interactions appear to be specific of brain TAGL and should be considered in assessing any direct neuro-hormonal role to ACTH or physiological polyamines in brain.     

Short‐term intravenous insulin infusion is associated with reduced expression of NADPH oxidase p47phox subunit in monocytes from type 2 diabetes patients

Hyperglycemia is a well‐known inducing factor of oxidative stress through activation of NADPH oxidase. In addition to its plasma glucose lowering effect, insulin may also have antioxidant activity and was shown to downregulate NADPH oxidase expression in vitro. In this study, we show that a short‐term (3‐day) intravenous insulin infusion in patients with type 2 diabetes induces normalization of both glycemia and mRNA expression of circulating monocyte p47^phox subunit.     

Network of Contacts between Cattle Herds in a French Area Affected by Bovine Tuberculosis in 2010

France attained ‘Officially Tuberculosis‐Free’ status in 2000. However, the Côte d’Or department (a French administrative unit) has since seen an increase in bovine tuberculosis (bTB) cases, with 35% of cases attributed to neighbourhood contamination. The aim of this study was to investigate the characteristics of neighbourhood contacts in an area affected by bTB in 2010, through the use of social network methods. We carried out a survey to determine the frequency and distribution of between‐herd contacts in an area containing 22 farms. Contacts were weighted, as not all types of contact carried the same risk of bTB transmission. Cattle movement was considered to be associated with the highest risk, but was not observed within the studied area during the study period. Contact with wild boars was the most frequent type of contact, but was associated with a very low risk. Direct cattle‐to‐cattle contacts in pasture and contacts with badger latrines were less frequent, but entailed a greater risk of M. bovis transmission. Centrality values were heterogeneous in these two networks. This would enable the disease to spread more rapidly at the start of epidemics than in a perfect randomly mixed population. However, this situation should also result in the total number of infected herds being smaller. We attributed 95% of the contacts to direct contact in pasture or contact with wild boars or badger latrines. Other kinds of contact occurred less frequently (equipment sharing, cattle straying) or did not occur at all (attendance at a show). Most of the contact types were correlated, but none was sufficient in itself to account for all contacts between one particular farm and its neighbours. Contacts with neighbours therefore represent a challenge for the implementation or improvement of control measures.     

Incorporating a class of constraints into the dynamics of optimal control problems

A method is proposed to systematically transform a constrained optimal control problem (OCP) into an unconstrained OCP, which can be treated in the standard calculus of variations. The considered class of constraints comprises up to m input constraints and m state constraints with well‐defined relative degree, where m denotes the number of inputs of the given nonlinear system. Starting from an equivalent normal form representation, the constraints are incorporated into a new system dynamics by means of saturation functions and differentiation along the normal form cascade. This procedure leads to a new unconstrained OCP, where an additional penalty term is introduced to avoid the unboundedness of the saturation function arguments if the original constraints are touched. The penalty parameter has to be successively reduced to converge to the original optimal solution. The approach is independent of the method used to solve the new unconstrained OCP. In particular, the constraints cannot be violated during the numerical solution and a successive reduction of the constraints is possible, e.g. to start from an unconstrained solution. Two examples in the single and multiple input case illustrate the potential of the approach. For these examples, a collocation method is used to solve the boundary value problems stemming from the optimality conditions. Copyright © 2009 John Wiley & Sons, Ltd.     

Coverage of pelvis and thigh region by pedicled perforator flap like deep inferior epigastric perforator (DIEP)

The deep inferior epigastric perforator flap (DIEP) is a variation of the transverse rectus abdominis myocutaneous flap (TRAM). This flap was used as a pedicled flap to reconstruct the pelvis and thigh region after resection for cancer (four cases). Various flaps have been described for covering theses tissue defects but we prefer this perforator flap for its many advantages. This flap is very reliable and generates minimal functional sequelae on donor site. This flap is useful to cover soft tissue defects after vascular and oncologic surgery, a situation that was rarely reported to our knowledge.     

Composite tissue allotransplantation and reconstructive surgery: first clinical applications

OBJECTIVE: To review the first clinical cases of composite tissue allotransplantation (CTA) for reconstructive surgery and to discuss the outcome of and indications for these procedures in the context of chronic immunosuppression. SUMMARY BACKGROUND DATA: The first human hand transplant was performed in 1998. This procedure, as well as other composite tissue transplants, offers the potential for correcting untreatable large tissue defects. However, concerns remain regarding obligatory chronic immunosuppression and long-term functional results. METHODS: All the CTAs performed in humans that have been published or documented were reviewed. The preexisting clinical conditions and surgical procedures and the immunosuppressive therapy are described. The functional results and the complications or side effects of the treatment are detailed. RESULTS: Vascularized tendons (two cases), vascularized femoral diaphyses (three cases), knees (five cases), hands (four bilateral and seven unilateral cases), larynx (one case), and nonvascularized peripheral nerves (seven cases) have been transplanted in humans in the past decade. Rejection was prevented in most cases without difficulty. Early results are encouraging, particularly for hand and larynx transplants, but will need to be evaluated in the long term and in a larger number of patients. CONCLUSIONS: CTA holds great potential for reconstructive surgery but is at present restricted by the risks of chronic immunosuppression and uncertain long-term results.     

Imaging in diagnosis and treatment of vascular lesions of the hand

Vascular lesions of the hand are challenging for diagnosis and treatment. These lesions are far more common than malignant tumors. Clinical presentation may be confusing and correct identification by imaging is sometimes mandatory. Standard X-rays and doppler ultrasound examination are the first modalities to be used. Doppler ultrasound help to characterize the lesion or/and to assess the flow velocity within the lesion. It allows to separate the high flow lesions (hemangioma, arteriovenous malformation) from the low or no flow lesions (venous malformation, cystic lymphangioma). MR imaging is the gold examination to define the size and the extension of the lesion to adjacent structures. Careful clinical and imaging evaluation and multidisciplinary staff decision are crucial before to propose embolotherapy and/or surgical treatment. In case of persistent doubt, a biopsy must be required. AVM must be excluded before to propose this biopsy sample. Interventional radiology can be used alone or in combination with surgery to treat vascular malformation (arteriovenous, lymphatic, venous, or mixed). Embolisation may either be done by percutaneous approach (all malformations) or by intravascular catheterization (arteriovenous malformation). Hemangioma is a benign tumor which most often spontaneously involutes with age. Vascular malformations of the hand are difficult to eradicate completely either with embolization or surgery or both. Recurrences are frequent. Management in multidisciplinary staff is mandatory and long follow-up is needed.