Influence of current on field-driven domain wall motion in permalloy nanowires from time resolved measurements of anisotropic magnetoresistance.

The motion of magnetic domain walls in permalloy nanowires is investigated by real-time resistance measurements. The domain wall velocity is measured as a function of the magnetic field in the presence of a current flowing through the nanowire. We show that the current can significantly increase or decrease the domain wall velocity, depending on its direction. These results are understood within a one-dimensional model of the domain wall dynamics which includes the spin transfer torque.

Juxtaglomerular apparatus T-cell infiltration affects glomerular structure in Type 1 diabetic patients.

AIMS/HYPOTHESIS: Type 1 diabetes is an autoimmune disorder associated with T-cell mediated injury to multiple endocrine tissues. T-cell infiltration of the juxtaglomerular apparatus could be associated with changes in local renin angiotensin system activity and, thus, with changes in the renal microenvironment. We examined the frequency of juxtaglomerular apparatus T-cell infiltration early in Type 1 diabetes and tested whether this is associated with renal structure and function. METHODS: We classified 89 Type 1 diabetic patients by immunohistochemical analysis as either juxtaglomerular apparatus T-cell positive ( n=37) or T-cell negative ( n=38). Borderline cases ( n=14) were not considered further. RESULTS: T-cell positive patients had a shorter duration of diabetes (6.7+/-2.5 years) than T-cell negative patients (9.2+/-5.0 years, p=0.011) and lower albumin excretion rate, but they had a similar glomerular filtration rate and blood pressure. Renal biopsy morphometric analysis showed similar glomerular basement membrane width and mesangial fractional volume in these two groups. However, glomerular capillary surface density ( p=0.0012) and filtration surface per glomerulus ( p=0.0155) were greater in the T-cell positive patients. CONCLUSION/INTERPRETATION: Increased filtration surface per glomerulus could be associated with glomerular filtration rate preservation in diabetes. Thus, juxtaglomerular apparatus immunologic injury in Type 1 diabetes patients could delay the clinical consequences of diabetic nephropathy.

Effect of optical spin injection on ferromagnetically coupled Mn spins in the III-V magnetic alloy semiconductor (Ga,Mn)As.

We report on the new type of photoinduced magnetization in ferromagnetic (Ga,Mn)As thin films. Optically generated spin-polarized holes change the orientation of ferromagnetically coupled Mn spins and cause a large change in magnetization, being 15% of the saturation magnetization, without the application of a magnetic field. The memorization effect has also been found as a trace after the photoinduced magnetization. The observed results suggest that a small amount of nonequilibrium carrier spins can cause collective rotation of Mn spins presumably through the p-d exchange interaction.

Mechanism of nitric oxide-induced apoptosis in human neuroblastoma SH-SY5Y cells.

We have attempted to elucidate the precise mechanism of nitric oxide (NO)-induced apoptotic neuronal cell death. Enzymatic cleavages of DEVD-AFC, VDVAD-AFC, and LEHD-AFC (specific substrates for caspase-3-like protease (caspase-3 and -7), caspase-2, and caspase-9, respectively) were observed by treatment with NO. Western blot analysis showed that pro-forms of caspase-2, -3, -6, and -7 are decreased during apoptosis. Interestingly, Ac-DEVD-CHO, a caspase-3-like protease inhibitor, blocked not only the decreases in caspase-2 and -7, but also the formation of p17 from p20 in caspase-3 induced by NO, suggesting that caspase-3 exists upstream of caspase-2 and -7. Bongkrekic acid, a potent inhibitor of mitochondrial permeability transition, specifically blocked both the loss of mitochondrial membrane potential and subsequent DNA fragmentation in response to NO. Thus, NO results in neuronal apoptosis through the sequential loss of mitochondrial membrane potential, caspase activation, and degradation of inhibitor of caspase-activated DNase (CAD) (CAD activation).

Glomerular structural changes and structural-functional relationships at early stage of diabetic nephropathy in Japanese type 2 diabetic patients.

Details of renal structural changes and structural-functional relationships at the early stage of diabetic nephropathy (DN) in type 2 diabetes are not well known. The present review focuses on these topics from previous studies using light and electron microscopic morphometric analysis. Glomerular hypertrophy, one of the histological changes in DN, is present in type 2 as well as in type 1 diabetic patients. However, mechanisms of increased glomerular size might be different from those in type 1 diabetes. Other typical glomerular changes, glomerular basement membrane thickening and mesangial expansion, are present in normoalbuminuric type 2 diabetic patients as a group. However, these parameters are similar between normo- and microalbuminuric patients. Renal structural-functional relationships cannot be seen in type 2 diabetic patients and therefore urinary albumin might not be a reliable indicator for glomerular structural changes in type 2 diabetic patients. Although previous reports showed reversibility of advanced diabetic glomerulosclerosis in type 1 diabetes by 10 years of strict glycemic control, there is no report regarding histological reversibility by therapeutic interventions in type 2 diabetic patients. In addition, it is unclear whether DN lesions are concordant or discordant with diabetic retinopathy grade in type 2 diabetes. From this information, renal structural changes or structural-functional relationships in type 2 diabetic patients might be heterogeneous and different from those in type 1 diabetic patients. Careful longitudinal study of renal structure and function including serial renal biopsy at the early stage of DN in type 2 diabetes is necessary.

Fusel oil as precursor for aroma generation by biotransformation using lipase: scientific note.

The feasibility of using mixtures of C4 and C5 chain-length aliphatic alcohols from fusel oil as the bulk organic media for lipase-mediated synthesis of laurate esters was assessed. Reaction mixtures consisted of lauric acid, lipase, solvent (if added), and appropriate amount of fusel oil (previously dehydrated with inorganic salts and molecular sieves). The influence of the reaction conditions such as substrate concentrations and temperature were investigated. Increased molar ratio of acyl donor to acyl acceptor allowed the esterification to proceed with no need for solvent addition.

Lipoprotein derangement during steroid treatment in minimal-change nephrotic syndrome.

To study the pathophysiology of hyperlipidemia in nephrotic syndrome, we compared lipid metabolism in the nephrotic stage (stage 1) and in stage 2, when albuminuria had subsided, in 11 patients with minimal-change disease treated with corticosteroid. High-density lipoprotein (HDL) levels were decreased and HDL contained more cholesterol and triglyceride per unit of protein in stage 1 in the patients than in age-matched healthy controls. The urinary protein level was positively correlated only with low-density lipoprotein (LDL) levels, suggesting that the increased albumin clearance stimulated LDL production. Serum cholesterol levels were positively correlated with apolipoprotein E levels and were negatively correlated with lecithin-cholesterol acyltransferase activity in the nephrotic stage; the opposite correlations were seen in controls. Although triglycerides in HDL had normalized at stage 2, triglycerides in LDL and very-low-density lipoprotein did not return toward normal until stage 3, when serum cholesterol levels were normalized.

Effect of administering calcium carbonate to treat secondary hyperparathyroidism in nondialyzed patients with chronic renal failure.

We administered calcium carbonate orally to determine its safety and efficacy in treating nondialyzed patients with mild to moderate renal failure and secondary hyperparathyroidism. Twenty patients with chronic renal failure (creatinine clearance levels ranging from 7.9 to 42.7 mL/min) participated in this study. After a 6-month control period, 3 g calcium carbonate was administered daily for 6 months. We studied the effect for another 6 months after discontinuation of the regimen. We found that serum-intact parathyroid hormone was suppressed from 183 +/- 149 pg/mL to 85 +/- 61 pg/mL (P < 0.05) by treatment. This suppression was achieved with no increase in serum concentrations of 1,25(OH)2D3. Serum phosphorus levels decreased from 3.4 +/- 0.7 to 3.0 +/- 0.7 mg/dL (P < 0.01) and Ca2+ concentration increased significantly from 2.40 +/- 0.12 mEq/L to 2.57 +/- 0.08 mEq/L (P < 0.001) at 6 months. These changes were reversed after the 6-month period of withdrawal from calcium carbonate. Deterioration of renal function was not exacerbated by the therapy. Calcium carbonate administration also suppressed the serum concentrations of alkaline phosphatase and osteocalcin, indicating that improvement of hyperparathyroid bone disease is possible without a vitamin D3 supplement at an earlier stage of renal failure. Thus, administration of 3 g oral calcium carbonate daily was highly effective in treating secondary hyperparathyroidism in patients with mild to moderate renal failure.