Low Altitude Solar Magnetic Reconnection, Type III Solar Radio Bursts, and X-ray Emissions.

Type III solar radio bursts are the Sun's most intense and frequent nonthermal radio emissions. They involve two critical problems in astrophysics, plasma physics, and space physics: how collective processes produce nonthermal radiation and how magnetic reconnection occurs and changes magnetic energy into kinetic energy. Here magnetic reconnection events are identified definitively in Solar Dynamics Observatory UV-EUV data, with strong upward and downward pairs of jets, current sheets, and cusp-like geometries on top of time-varying magnetic loops, and strong outflows along pairs of open magnetic field lines. Type III bursts imaged by the Murchison Widefield Array and detected by the Learmonth radiospectrograph and STEREO B spacecraft are demonstrated to be in very good temporal and spatial coincidence with specific reconnection events and with bursts of X-rays detected by the RHESSI spacecraft. The reconnection sites are low, near heights of 5-10 Mm. These images and event timings provide the long-desired direct evidence that semi-relativistic electrons energized in magnetic reconnection regions produce type III radio bursts. Not all the observed reconnection events produce X-ray events or coronal or interplanetary type III bursts; thus different special conditions exist for electrons leaving reconnection regions to produce observable radio, EUV, UV, and X-ray bursts.

Prediction of protective sensory loss, neuropathy and foot ulceration in type 2 diabetes.

OBJECTIVES: To prospectively determine clinical and biochemical characteristics associated with the development of peripheral neuropathy, loss of protective sensation, and foot ulceration in persons with type 2 diabetes mellitus (DM) over 7 years. RESEARCH DESIGN AND METHODS: Graded monofilament (MF) testing, vibration perception threshold, and neuropathy symptom questionnaires were undertaken in 206 participants with type 2 DM without peripheral vascular disease or history of foot ulceration and 71 healthy participants without DM at baseline and after 7 years. 6 monthly glycosylated hemoglobin (HbA1c) levels and annual serum lipid profiles were measured during follow-up of those with DM. Incident foot ulceration was recorded at follow-up. RESULTS: Taller stature and higher quartiles of serum triglyceride and HbA1c levels were associated with neuropathy at follow-up (p=0.008). Remission of baseline neuropathy was observed in 7 participants at follow-up. 9 participants with type 2 DM developed foot ulcers by the end of the study, only 1 at low risk. Mean HbA1c levels were higher in those who developed foot ulceration (p<0.0001). 1 participant with neuropathy throughout developed a Charcot foot. Failure to perceive 2 or more 2, 4 and 6 g MF stimuli at baseline predicted loss of protective sensation at follow-up. CONCLUSIONS: Tall stature and worse metabolic control were associated with progression to neuropathy. Mean HbA1c levels were higher in those who developed foot ulcers. Graded MF testing may enrich recruitment to clinical trials and assignation of high risk for foot ulceration.

A comparison of acute phase protein measurements and meat inspection findings in cattle.

The acute phase proteins haptoglobin (Hp) and serum amyloid-A (SAA) are increased in the blood of cattle with infectious or inflammatory diseases. As it is important to identify such cattle at meat inspection, a study was undertaken to compare the levels of Hp and SAA in blood samples from cattle at abattoir with the post-mortem meat inspection findings. The serum concentrations of Hp and SAA were determined in healthy beef cattle (n = 16); healthy dairy cows with no pathological conditions (n = 22); and cows with pathologic conditions (n = 62). The last group was subdivided into cows with acute pathological conditions (n = 10) and those with non-acute pathological conditions (n = 52). The mean (+/-SD) Hp levels in plasma from beef cattle and cows without pathological conditions found were 0.11 +/- 0.08 mg/mL and 0.02 +/- 0.03 mg/mL, respectively, and the difference was statistically significant (p < 0.001). However, mean Hp level in cattle with pathological conditions was 0.27 +/- 0.40 mg/mL, significantly higher than the mean values of either group of healthy animals (p < 0.01 versus healthy dairy cows and p < 0.001 versus healthy beef cattle). The mean SAA concentration in plasma samples from 22 healthy dairy cows (with no pathological conditions found) was 51 +/- 38 microg/mL, significantly higher (p < 0.01) than the mean SAA value of 29 +/- 21 microg/mL calculated from 16 plasma samples from healthy beef cattle. In the group of 62 cows with pathological conditions, the mean SAA level was 94 +/- 115 microg/mL being significantly higher than the respective value in either groups of healthy animals (p < 0.01 versus healthy cows and p < 0.001 versus healthy beef cattle). Considerations of the acute phase proteins results obtained from the animals with pathological conditions did not reveal a clear association between acute phase proteins levels and respective specific pathological conditions, although there was a significant correlation between Hp and SAA concentrations at the individual animal level when all results were considered (R = 0.75, n = 100, p < 0.001). Nevertheless, when the dairy cows with pathological conditions were subdivided, some significant differences in mean values of acute phase proteins were observed enabling differentiation between animals with (broadly categorised) acute and non-acute pathological conditions. Significantly higher Hp (p < 0.05) and SAA (p < 0.05) concentrations were found in the acute pathology group than in the non-acute pathology group. Overall, the result of the present study indicated that the acute phase protein analysis could be an additional and useful tool enabling separation of "suspect" from "non-suspect" animals during ante mortem inspection within a modernised meat inspection system.

The production and use of monoclonal antibodies to measure apolipoprotein B by a competitive enzyme-linked immunoassay.

The production of monoclonal antibodies to human lipoproteins is described. One of these antibodies, which was shown to be specific to apolipoprotein B, was used to develop a competitive enzyme-linked immunoassay for apolipoprotein B in serum samples. The antibody selected recognises apolipoprotein B in both low density and very low density lipoprotein particles, but there is no cross-reactivity with high density lipoprotein. There is no requirement for labelling of antigen or antibody used in the assay, and results obtained correlate well (r = 0.88) with measurements on serum samples using a radial immunodiffusion assay for apolipoprotein B.

Tissue hypoxia during fulminant hepatic failure.

To assess the adequacy of tissue oxygenation in fulminant hepatic failure, we measured arterial oxygen delivery, the affinity of hemoglobin for oxygen, mixed venous oxygen tension, and lactate concentration in 32 patients suffering grade IV encephalopathy. In the patients who died, median systemic vascular resistance and oxygen extraction ratio were significantly (p less than .005) lower than in those who survived (1268 vs. 1866 dyne . sec/cm5 . m2 and 20% vs. 25%, respectively) despite a significantly (p less than .01) greater oxygen delivery in the former group (716 vs. 570 ml/min . m2). Furthermore, nonsurvivors had significantly greater in vivo P50 and mixed venous lactate values (31 vs. 29.5 torr [p less than .02], and 5.1 vs 3.0 mmol/L [p less than .05], respectively). Only in survivors was the in vivo P50 related to the oxygen extraction ratio (r = 0.68 and p less than .01, compared with r = 0.03 in nonsurvivors). These results suggest that the fall in systemic vascular resistance is related to some form of arteriovenous shunting and that this is more severe in patients who die. The subsequent development of tissue hypoxia is an important prognostic factor in fulminant hepatic failure that may contribute to the occurrence of irreversible multiple organ failure.