Free-air exposure systems to scale up ozone research to mature trees.

Because seedlings and mature trees do not necessarily respond similarly to O(3) stress, it is critically important that exposure systems be developed that allow exposure of seedlings through to mature trees. Here we describe three different O(3) Free-Air Exposure Systems that have been used successfully for exposure at all growth stages. These systems of spatially uniform O(3) release have been shown to provide reliable O(3) exposure with minimal, if any, impact on the microclimate. This methodology offers a welcome alternative to chamber studies which had severe space constraints precluding stand or community-level studies and substantial chamber effects on the microclimate and, hence physiological tree performance.

New exposure-based metric approach for evaluating O(3) risk to North American aspen forests.

The United States and Canada currently use exposure-based metrics to protect vegetation from O(3). Using 5 years (1999-2003) of co-measured O(3), meteorology and growth response, we have developed exposure-based regression models that predict Populus tremuloides growth change within the North American ambient air quality context. The models comprised growing season fourth-highest daily maximum 8-h average O(3) concentration, growing degree days, and wind speed. They had high statistical significance, high goodness of fit, include 95% confidence intervals for tree growth change, and are simple to use. Averaged across a wide range of clonal sensitivity, historical 2001-2003 growth change over most of the 26 Mha P. tremuloides distribution was estimated to have ranged from no impact (0%) to strong negative impacts (-31%). With four aspen clones responding negatively (one responded positively) to O(3), the growing season fourth-highest daily maximum 8-h average O(3) concentration performed much better than growing season SUM06, AOT40 or maximum 1h average O(3) concentration metrics as a single indicator of aspen stem cross-sectional area growth.

6-Alkyl and 6-arylcarbamoyloximino pyrazolo[3,4-b][1,4]diazepines as potential fungicidal, insecticidal and herbicidal agents.

A series of 6-alkyl and 6-arylcarbamoyloximinopyrazolo[3,4-b][1,4]diazepines was prepared and evaluated for fungicidal, insecticidal and herbicidal activity. No one compound showed a general effect but individual compounds exhibited specific activities.

[First experiences with short-term lithium therapy in severe thyrotoxicosis]. / Erste Erfahrungen mit der Lithiumkurzzeittherapie bei schwerer thyreotoxikose.

Even nowadays the therapy of severe, particularly of contrast remedy-induced hyperthyroidism is not without any problems. According to reports in literature the application of lithium salts seems to be an expedient from this dilemma. We controlled the effect of a short-term lithium therapy of 7 days in combination with methimazole in comparison to a group with methimazole monotherapy. The examination showed a good effectiveness and tolerability of the lithium methimazole therapy. While the decrease of the thyroxin concentration in the two groups was not different, in the group with combined therapy a more rapid per cent decrease of the triiodothyronine concentration appeared. In primarily strict selection of the therapy severe side-effects are not to be expected. According to the results yielded up to now the described form of therapy is an actual enrichment for selected forms of hyperthyreosis.

Synthesis and anti-inflammatory evaluation of 3-methylthio-1,2,4-triazines, 3-alkoxy-1,2,4-triazines, and 3-aryloxy-1,2,4-triazines.

To develop nonacidic, nonsteroidal anti-inflammatory agents without GI complications, a series of asymmetric triazines was synthesized and evaluated for anti-inflammatory efficacy in the carrageenan-induced pedal edema assay. Toxicity was estimated by determination of approximate LD50 values in mice. Twenty-five compounds possessed activity comparable to the standard, indomethacin. Thirteen of the 25 compounds were selected for dose-response evaluation in the carrageenan assay based on their relative toxicity and anti-inflammatory activity. Neurotoxicity of the 13 triazines was estimated by determination of NTD50 values in mice. Five of the 13 compounds tested in the dose-response assay were active in terms of anti-inflammatory efficacy (ED50 values) and lack of overt neurotoxicity (NTD50 values) when compared to indomethacin. To determine the effect of these five developmental triazines on chronic inflammation, they were evaluated in the adjuvant-induced polyarthritis assay. One was comparable to indomethacin in reducing adjuvant-induced inflammation in this assay.

Synthesis and antihypertensive activity of novel 3-hydrazino-5-phenyl-1,2,4-triazines.

In an effort to develop antihypertensive agents with peripheral vasodilator activity, a series of 40 novel 3-hydrazino-5-phenyl-1,2,4-triazines (II) were synthesized and evaluated in the spontaneously hypertensive rat assay (SHR assay). Based on the performance of the structurally related standard, hydralazine (I), 15 triazines were active. Thirteen of these hypotensive triazines possessed LD50 values in the mouse greater than I (LD50 = 100 mg/kg); only one active triazine had an LD50 value greater than 300 mg/kg (11d). Four asymmetric triazines had moderate antihypertensive activity and LD50 values greater than 300 mg/kg (6b, 7c, 8f, and 9g). Based on the relationship between toxicity and antihypertensive activity, three triazines (8f, 9g, and 11d) were chosen for dose-responses studies in the SHR assay. None were as efficacious as I, but all three were less toxic, resulting in similar therapeutic indices relative to I.

Synthesis and antiinflammatory evaluation of substituted isophthalonitriles, trimesonitriles, benzonitriles, and terephthalonitriles.

In an effort to develop nonacidic, nonsteroidal, antiinflammatory agents without gastrointestinal complications, a series of cyanobenzenes was synthesized for antiinflammatory evaluation. Twenty-seven substituted isophthalonitriles, 19 trimesonitriles, 30 benzonitriles, and 16 terephthalonitriles were tested in the rat utilizing the carrageenan-induced pedal edema assay. Based on the performance of phenylbutazone in this assay (43.8% reduction at 100 mg/kg), six compounds, dosed at 50 mg/kg, produced reductions in inflammation comparable to this standard. However, the LD50 value of each compound dosed at this level was in the range of 40--56 mg/kg in the mouse; therefore, further the LD50 value of each compound dosed at this level was in the range of 40--56 mg/kg in the mouse; therefore, further study was not warranted. Fifteen compounds possessed activity in excess of 20% reduction at 200 mg/kg and also possessed LD50 values greater than 300 mg/kg. Of these cyanobenzenes, trimesonitrile (16), 4-chlorobenzonitrile, 2-chloroterephthalonitrile, and 2-fluoroterephthalonitrile with reductions in edema of 32, 30, 46, and 49%, respectively, represent the best candidates for subsequent study.

Synthesis of ethyl 6-substituted-chroman- and -chromone-2-carboxylates. A comparative structure-activity study employing the 6-phenyl and phenoxy analogs in the triton hyperlipidemic rat model.

To explore the effect of lipophilicity on antilipidemic activity in the Triton WR-1339 induced hyperlipidemic rat model we synthesized the 6-cyclohexyl, phenyl, and phenoxy analogs of ethyl chroman-2-carboxylate. Results obtained were analyzed in light of the biological activity observed for the 6-chloro-substituted and unsubstituted chromans, the 6-chlorochroman-4-one ester, and the 6-chloro-, phenyl-, and phenoxychromone esters. The suggestion is made that chromones likely exert their antilipidemic effects by a somewhat different set of mechanisms than do the chromans and clofibrate. Whereas the 6-chlorochromanone ester is inactive, the 6-chlorochromone ester is active in both normal and hyperlipidemic Sprague-Dawley rats. The major differential effect was observed for ethyl 6-cyclohexylchroman-2-carboxylate which did not lower cholesterol levels but returned triglyceride levels to normal in hyperlipidemic rats.

[Secretion of insulin and disorders in fatty acid metabolism in diabetic patients with coronary heart diseases]. / Insulinsekretion und Fettstoffwechselstörungen bei Diabetikern mit koronarer Herzerkrankung

The behaviour of the blood glucose, the insulin secretion, the free fatty acids, of glycerol and of the triglycerides after glucose tolerance test was examined in 66 patients with condition after myocardial infarction. 16 of the 34 patients loaded with an oral glucose tolerance test and 25 of the 31 patients loaded with an intravenous glucose infusion test showed disturbances of the glucose tolerance. The insulin secretion was significantly different neither in normal nor disturbed or lying in the borderline region glucose tolerance. With increasing glycerol values a significant deterioration of the glucose tolerance developed. The triglyceride values in the plasma increased with increasing insulin secretion. The results seem to be important with regard to the pathogenetic relations between the carbohydrate and fat metabolism and might be fo importance also for a differentiated therapy.

New technique for rapid purification, entrapment, and recovery of enterotoxin A from a liquid chamber by polyacrylamide gel electrophoresis.

Electrophoreis of enterotoxin into a middle liquid section of a polyacrylamide gel column enhances recovery for serological assay.

Heat inactivation of enterotoxin A from Staphylococcus aureus in veronal buffer.

Serological tests were used to determine the slope of the thermal inactivation curve of crude enterotoxin A in Veronal buffer (pH 7.2), and the resulting z value was 27.8 C. (50 F). Serological assays also showed that the heat inactivation at each time-temperature depended on the original concentration of enterotoxin A. The usefulness of the Oudin tube serological test for determining end points of inactivation of naturally produced enterotoxin A (not concentrated) is discussed. We concluded that this test cannot be used to determine end points of heat inactivation for enterotoxin A in the minute quantities naturally produced in foods.