Electrically induced and detected Néel vector reversal in a collinear antiferromagnet.

Antiferromagnets are enriching spintronics research by many favorable properties that include insensitivity to magnetic fields, neuromorphic memory characteristics, and ultra-fast spin dynamics. Designing memory devices with electrical writing and reading is one of the central topics of antiferromagnetic spintronics. So far, such a combined functionality has been demonstrated via 90° reorientations of the Néel vector generated by the current-induced spin orbit torque and sensed by the linear-response anisotropic magnetoresistance. Here we show that in the same antiferromagnetic CuMnAs films as used in these earlier experiments we can also control 180° Néel vector reversals by switching the polarity of the writing current. Moreover, the two stable states with opposite Néel vector orientations in this collinear antiferromagnet can be electrically distinguished by measuring a second-order magnetoresistance effect. We discuss the general magnetic point group symmetries allowing for this electrical readout effect and its specific microscopic origin in CuMnAs.

Kidney Graft Leiomyosarcoma: A Case Report.

BACKGROUND: Kidney transplant (KT) recipients have a higher incidence of malignancy than the general population. Smooth muscle tumors (SMT), including leiomyosarcoma, are rare in kidney transplant recipients, and most cases are associated with Epstein-Barr virus (EBV) infection. CASE REPORT: A 57-year-old man received a deceased donor kidney transplant at the age of 53 years, with 5 human leukocyte antigen (HLA) mismatches. Before the transplantation, the patient was IgG positive for EBV viral capsid antigen (VCA), negative for IgM EBV VCA, and also negative for IgG EBV nuclear antigen (EBNA), suggesting a prior EBV infection. He received immunosuppressive induction with basiliximab, and maintenance with tacrolimus, mycophenolate mofetil, and prednisolone. Two years after transplantation, he had an acute cellular rejection episode treated with methylprednisolone. An increased graft size was found 4 years after transplantation. A computed tomographic scan showed 3 solid tumors involving the renal graft with extension to the perinephric fat; no secondary localizations were found. A nephrectomy of the graft was performed. The histologic diagnosis was a high-grade leiomyosarcoma. In situ hybridization for EBV was negative. Nine months after nephrectomy, local recurrence was diagnosed. The surgical approach was unsuccessful, and the patient died after a brief period. CONCLUSION: Kidney leiomyosarcoma is a very rare clinical condition. Most of these neoplasms that arise in transplanted recipients are associated with EBV in tumor tissue. Only one case of renal graft leiomyosarcoma without EBV RNA in the tumor has been previously reported.

Behavioral changes induced by cocaine in mice are modified by a hyperlipidic diet or recombinant leptin.

The objective of the present study was to determine if the acute behavioral effects of cocaine acutely administered intraperitoneally (ip) at doses of 5, 10 and 20 mg/kg on white male CF1 mice, 90 days of age, would be influenced by leptin acutely administered ip (at doses of 5, 10 and 20 microg/kg) or by endogenous leptin production enhanced by a high-fat diet. The acute behavioral effects of cocaine were evaluated in open-field, elevated plus-maze and forced swimming tests. Results were compared between a group of 80 mice consuming a balanced diet and a high-fat diet, and a group of 80 mice fed a commercially available rodent chow formula (Ralston Purina) but receiving recombinant leptin (rLeptin) or saline ip. Both the high-fat-fed and rLeptin-treated mice showed decreased locomotion in the open-field test, spent more time in the open arms of the elevated plus-maze and showed less immobility time in the forced swimming test (F(1,68) = 7.834, P = 0.007). There was an interaction between diets and cocaine/saline treatments in locomotion (F(3,34) = 3.751, P = 0.020) and exploration (F(3,34) = 3.581, P = 0.024). These results suggest that anxiolytic effects and increased general activity were induced by leptin in cocaine-treated mice and that low leptin levels are associated with behavioral depression. Chronic changes in diet composition producing high leptin levels or rLeptin treatment may result in an altered response to cocaine in ethologic tests that measure degrees of anxiety and depression, which could be attributed to an antagonistic effect of leptin.

Behavioral changes induced by cocaine in mice are modified by a hyperlipidic diet or recombinant leptin

The objective of the present study was to determine if the acute behavioral effects of cocaine acutely administered intraperitoneally (ip) at doses of 5, 10 and 20 mg/kg on white male CF1 mice, 90 days of age, would be influenced by leptin acutely administered ip (at doses of 5, 10 and 20 æg/kg) or by endogenous leptin production enhanced by a high-fat diet. The acute behavioral effects of cocaine were evaluated in open-field, elevated plus-maze and forced swimming tests. Results were compared between a group of 80 mice consuming a balanced diet and a high-fat diet, and a group of 80 mice fed a commercially available rodent chow formula (Ralston Purina) but receiving recombinant leptin (rLeptin) or saline ip. Both the high-fat-fed and rLeptin-treated mice showed decreased locomotion in the open-field test, spent more time in the open arms of the elevated plus-maze and showed less immobility time in the forced swimming test (F(1,68) = 7.834, P = 0.007). There was an interaction between diets and cocaine/saline treatments in locomotion (F(3,34) = 3.751, P = 0.020) and exploration (F(3,34) = 3.581, P = 0.024). These results suggest that anxiolytic effects and increased general activity were induced by leptin in cocaine-treated mice and that low leptin levels are associated with behavioral depression. Chronic changes in diet composition producing high leptin levels or rLeptin treatment may result in an altered response to cocaine in ethologic tests that measure degrees of anxiety and depression, which could be attributed to an antagonistic effect of leptin.

'Tipping the balance towards primary health care': managing change at the local level.

This article addresses the problem of managing change at the local level, by focusing on the experience of the research and action project 'Tipping the Balance Towards Primary Health Care'. The experience of this project and case studies in other countries is abstracted. It includes some characteristics of the actors and forces under which local services operate, pointing to some opportunities and constraints in managing change and development, as well as organizational relationships in the field of primary health care. In this article it is argued that the ongoing structural reform is a necessary prerequisite, but it is not the unique key, for solving local health services problems. If the mission of the health sector is to satisfy the real and the perceived needs of the population, skilled professionals, appropriate technology, and enough financial resources must be allocated to the local level.