Bioelectrochemical monitoring of phenols and aromatic amines in flow injection using novel plant peroxidases

An amperometric flow system combined with a glucose oxidase-mutarotase reactor was optimized and used to determine aromatic amines and phenols using peroxidase-modified graphite electrodes. An increase in currents upon injection of the analyzed substrate was shown to be approximated by a Michaelis-Menten type dependence. The detection limit was calculated as 3 times the noise, and the sensitivity was calculated as Imax/K(m)app. Commercially available horseradish peroxidase was compared with tobacco anionic and peanut cationic peroxidases for determination of aromatic amines and phenols. Detection limits of 10 nM for determination of o-aminophenol and o- and p-phenylenediamine achieved with a tobacco peroxidase-modified electrode give a promise for further improvements in sensitivities and detection limits of biosensors.     

ISCOMs: an adjuvant with multiple functions

Glucagon causes transient hyperglycemia and persistent hypoaminoacidemia, but the mechanisms of this action are unclear. To address this question, the present study measured the effects of glucagon on glucose, leucine, phenylalanine, and glutamine kinetics. Seven healthy subjects each underwent three pancreatic clamp studies (octreotide 30 ng/kg/min, insulin 0.15 mU/kg/min, and glucagon 1.4 ng/kg/min) lasting 7 hours. During the last 3.5 hours of the studies, glucagon infusion was either unchanged (study 0) or increased to 4 and 7 ng/kg/min (studies 1 and 2). The higher glucagon infusion rates increased the glucagon concentration by 50% and 100%, respectively. [6,6-(2)H2]glucose, [2-(15)N]glutamine, 2H5-phenylalanine, and 2H3-leucine were infused to quantify the respective fluxes. Glucagon transiently increased glucose concentrations by stimulating glucose production, which peaked in 15 minutes to 3.82 +/- 0.36 and 4.21 +/- 0.33 mg/kg/min in studies 1 and 2 and then returned to the postabsorptive levels. Glucagon decreased the glutamine concentration (-10% +/- 2% and -22% +/- 2% in studies 1 and 2 v study 0, P < .05), because glutamine uptake became greater than glutamine release (balance from -1.9 +/- 0.9 in study 0 to -8.1 +/- 1.1 and -13.6 +/- 1.0 micromol/kg/h in studies 1 and 2, P < .01). Glucagon decreased the leucine concentration (-11% +/- 3% in study 2 v study 0, P < .02) and caused a small increment in proteolysis (+6% in study 2 v study 0, P < .01) that was related to the decrement in glutamine concentrations. Phenylalanine kinetics were not significantly affected. These results show that glucagon promotes the uptake of gluconeogenic substrates but does not increase their release, suggesting that glucagon-induced hyperglycemia is short-lived because glucagon fails to provide more fuel for gluconeogenesis. The small increase in proteolysis and the depletion of circulating glutamine prove that physiologic hyperglucagonemia can contribute to protein catabolism.     

The use of mountain air therapy for the correction of acid formation in patients with hypo- and hyperacidic syndromes

In a consecutive series of 326 patients with primary lung cancer, sarcoid reactions were observed in the regional lymph node or resected lung in 7 patients (2.2%). The average age of the 7 patients, 4 males and 3 females, was 54 years, range 45-70. All the patients underwent lobectomy. The sites in which sarcoid reactions were found were the regional lymph node (N) in 3 patients, the lung parenchyma (L) in 2, N and L in 1, and the tumor stroma in 1. The histologic types were adenocarcinoma in 4 patients, squamous cell carcinoma in 2, and small cell carcinoma in 1. Two patients died of recurrence and myocardial infarction, and five patients are alive, range 5-64 months. The patients with lung cancer complicating sarcoid reactions were significantly younger than the control group (p<0.01), and not significant in prognosis. We conclude that the complication of sarcoid reactions do not influence the prognosis, but that the sarcoid reactions may be a local reaction or resistance to cancer cells.     

A case of Oberling's retroperitoneal xanthogranuloma in pilot

A rare case of retroperitoneal mass identified in the pilot, aged 48, is described. There has been noted the complexity of differential diagnosis between the benign and malignant process associated with the given type of tumor which led to some problems when making an expert decision. The tumor was found to be non-removable, however, considering the good clinical state of the pilot, he was permitted of flying activity which he continues to perform successfully more than 10 years. The pilot state remains good which confirms the benign character of the process. The observation is of great interest both clinically and from the flight-surgeon's appraisal standpoint.     

Reaction of the type III iodothyronine deiodinase with the affinity label N-bromoacetyl-triiodothyronine

The type III iodothyronine deiodinase (ID-III) catalyzes the inner ring deiodination and, thus, the inactivation of the thyroid hormones T4 and T3. ID-III activity in rat brain, rat placenta and embryonic chicken liver is inhibited by the affinity label N-bromoacetyl-T3 (BrAcT3) with an affinity similar to that of T3. Reaction of rat brain and placenta microsomes with BrAc[125I]T3 resulted in the extensive labeling of a 32 kDa protein (p32). However, p32 was also prominently labeled in fetal rat liver microsomes which have no ID-III activity. Labeling of p32 was not influenced by 100 microM substrate analogs or inhibitors of ID-III, some of which completely inhibit ID-III activity at 1 microM. BrAc[125I]T3 labeling of embryonic chicken liver microsomes did not reveal p32 or another protein possibly related to ID-III. In contrast to previous suggestions, it is unlikely that p32 represents ID-III or a subunit thereof.