Salicylic Acid in Rice (Biosynthesis, Conjugation, and Possible Role)

Salicylic acid (SA) is a natural inducer of disease resistance in some dicotyledonous plants. Rice seedlings (Oryza sativa L.) had the highest levels of SA among all plants tested for SA content (between 0.01 and 37.19 [mu]g/g fresh weight). The second leaf of rice seedlings had slightly lower SA levels than any younger leaves. To investigate the role of SA in rice disease resistance, we examined the levels of SA in rice (cv M-201) after inoculation with bacterial and fungal pathogens. SA levels did not increase after inoculation with either the avirulent pathogen Pseudomonas syringae D20 or with the rice pathogens Magnaporthe grisea, the causal agent of rice blast, and Rhizoctonia solani, the causal agent of sheath blight. However, leaf SA levels in 28 rice varieties showed a correlation with generalized blast resistance, indicating that SA may play a role as a constitutive defense compound. Biosynthesis and metabolism of SA in rice was studied and compared to that of tobacco. Rice shoots converted [14C]cinnamic acid to SA and the lignin precursors p-coumaric and ferulic acids, whereas [14C]benzoic acid was readily converted to SA. The data suggest that in rice, as in tobacco, SA is synthesized from cinnamic acid via benzoic acid. In rice shoots, SA is largely present as a free acid; however, exogenously supplied SA was converted to [beta]-O-D-glucosylSA by an SA-inducible glucosyltransferase (SA-GTase). A 7-fold induction of SA-GTase activity was observed after 6 h of feeding 1 mM SA. Both rice roots and shoots showed similar patterns of SA-GTase induction by SA, with maximal induction after feeding with 1 mM SA.

Combined intravenous and intra-arterial recombinant tissue plasminogen activator in acute ischemic stroke

BACKGROUND AND PURPOSE

A retrospective analysis was performed on 20 consecutive patients who presented with severe acute ischemic stroke and were evaluated for a combined intravenous (IV) and local intra-arterial (IA) recombinant tissue plasminogen activator (rtPA) thrombolytic approach within 3 hours of onset.

METHODS

Twenty consecutive patients with carotid artery distribution strokes were evaluated and treated using a combined IV and IA rtPA approach over a 14-month period (September 1998 to October 1999). rtPA (0.6 mg/kg) was given intravenously (maximum dose 60 mg); 15% of the IV dose was given as bolus, followed by a continuous infusion over 30 minutes. A maximal IA dose, up to 0.3 mg/kg or 24 mg, whichever was less, was given over a maximum of 2 hours. IV treatment was initiated within 3 hours in 19 of 20 patients. All 20 patients underwent angiography, and 16 of 20 patients received local IA rtPA.

RESULTS

The median baseline National Institutes of Health Stroke Scale (NIHSS) score for the 20 patients was 21 (range 11 to 31). The median time from stroke onset to IV treatment was 2 hours and 2 minutes, and median time to initiation of IA treatment was 3 hours and 30 minutes. Ten patients (50%) recovered to a modified Rankin Scale (mRS) of 0 or 1; 3 patients (15%), to an mRS of 2; and 5 patients (25%), to an mRS of 4 or 5. One patient (5%) developed a symptomatic intracerebral hemorrhage and eventually died. One other patient (5%) expired because of complications from the stroke.

CONCLUSIONS

We believe that the greater-than-expected proportion of favorable outcomes in these patients with severe ischemic stroke reflects the short time to initiation of both IV and IA thrombolysis.

Prevalence of periodontal pathogens in subgingival lesions, atherosclerotic plaques and healthy blood vessels: a preliminary study

BACKGROUND AND OBJECTIVE

Previous studies have reported different periodontal bacteria in atherosclerotic lesions, but their involvement in plaque formation remains unclear. The aim of the present study was to investigate the presence of 20 periodontal bacteria in atherosclerotic samples and healthy blood vessels (used as controls) and to clarify their relationship in regard to clinical and bacteriological periodontal status.

MATERIAL AND METHODS

The day before vascular surgery the patients had a thorough periodontal examination and bacteriological samples were taken from periodontally diseased sites. Atheromatous plaques, internal mammary arteries and saphenous veins were harvested during surgery. A DNA-DNA hybridization procedure was used to screen periodontal and vascular samples for the 20 selected bacterial species.

RESULTS

Periodontal samples from the severe periodontitis group were found to have a higher prevalence and biomass of bacterial species than the moderate periodontitis group. In vessel samples, the prevalence of the same 20 bacterial species analyzed together was similar in the two groups, except for saphenous veins.

CONCLUSION

The presence of periodontal pathogens in atherosclerotic plaques and in apparently healthy vessels appeared to reflect a higher level of bacteremia rather than infection of endothelial cells.

Fluvoxamine maleate in the treatment of depression: a single-center, double-blind, placebo-controlled comparison with imipramine in outpatients

The efficacy and safety of fluvoxamine maleate, a selective serotonin reuptake inhibitor, was compared with placebo and imipramine in patients with major depressive disorder. Previous literature has cited a dose range of 100 to 300 mg/day of fluvoxamine maleate for the treatment of major depression; however, this study demonstrates that a dose range of 50 to 150 mg/day is as effective as imipramine (80-240 mg/day). After a 1- to 2-week, single-blind, placebo washout phase, 150 depressed outpatients were randomized to double-blind treatment with fluvoxamine maleate (50-150 mg/day), imipramine (80-240 mg/day), or placebo for 6 weeks. Fluvoxamine produced a significant therapeutic benefit over placebo (p < or = 0.05) as assessed by the total score on the Hamilton Rating Scale for Depression; imipramine (80-240 mg/day) produced similar results. The secondary outcome variables (i.e., Clinical Global Impression severity of illness item and 56-Item Hopkins Symptom Checklist depression factor) also showed significant differences between fluvoxamine maleate and placebo during three of the four final weeks of the study. Both fluvoxamine maleate and imipramine appeared to be safe and well tolerated by the majority of patients. As expected from the pharmacology of these agents, the imipramine groups reported more anticholinergic effects (dry mouth, dizziness, and urinary retention) and electrocardiographic effects, whereas the fluvoxamine group reported more nausea, somnolence, and abnormal ejaculation. The majority of these adverse events were mild to moderate and, with the exception of dry mouth (imipramine) and abnormal ejaculation (fluvoxamine), were transient. The data clearly demonstrate the antidepressant activity and tolerability of fluvoxamine maleate (50-150 mg/day) as compared with placebo; it is also as effective as the tricyclic antidepressant imipramine (80-240 mg/day) in patients with major depressive disorder.

Electrocardiographic findings during extended clinical trials of fluvoxamine in depression: one years experience

INTRODUCTION

Fluvoxamine, a selective serotonin reuptake inhibitor (SSRI), is used to treat depression. No significant effect on the electrocardiogram (ECG) has been reported during short-term controlled studies of SSRI's. We report a long-term (1 year) multi-center, double-blind controlled study of the ECG during treatment of depression with fluvoxamine (FX), active control medication (TCA), and placebo (PLA).

METHOD

Initially ECGs were obtained from 1840 physically healthy, depressed outpatients who were treated with FX, TCA, or PLA for 6 weeks. A subset of these patients continued treatment for up to one year. Complete sets of ECGs were obtained from 462 of these patients. Patients whose depression was substantially improved in the initial 6-week study ("responder") received the same medication. Non-responders received a blinded active medication. Pre-treatment, intra-study, and past-treatment ECGs were recorded according to protocol. One blinded electrocardiographer measured and analyzed all ECG data. The effects of each medication upon the ECG were measured and compared.

RESULTS

Of the 462 patients, 311 used FX, 100 used TCA and 51 used PLA. Analyses of ECG data for each treatment focused on changes in ECG measurements; % of normal ECGs, and % of individual ECG findings. The ECG changes during FX treatment were less than or not significantly different from the ECG changes with PLA treatment. The changes with TCA were as expected.

CONCLUSIONS

Fluvoxamine treatment of depression for one year was not associated with any significant effect on the ECG.

Mapping and quantitation of proteins from discrete nuclei and other areas of the rat brain by two-dimensional gel electrophoresis

A map of the location and relative concentration of a number of different proteins present in 25 distinct neuroanatomical regions of the male rat brain has been established utilizing two-dimensional polyacrylamide gel electrophoresis. The regions examined include cortical areas as well as nuclei from the hypothalamus, amygdala, thalamus, forebrain, and hindbrain. Tissue samples were obtained from each region of interest by microdissection. Proteins within these samples were first separated by charge using the technique of isoelectric focusing. In the second dimension, proteins were separated by mass on polyacrylamide slab gels containing sodium dodecyl sulfate. Proteins were visualized using a highly sensitive silver stain and quantitated by computerized scanning densitometry. The results demonstrate that all proteins examined varied somewhat in concentration among the different brain regions. The majority (53%) of polypeptides selected for quantitation were found to vary less than 4-fold in concentration between the neuroanatomical areas with the lowest and highest detected amounts. In contrast, approximately 10% of the proteins examined varied widely in the quantity measured in each brain region, with concentration values ranging more than 10-fold between the regions with the lowest and highest detected amounts. This atlas is a first attempt at systematically classifying the mass, charge, and relative concentration of proteins present in a variety of regions of the rat brain. The system presented here will serve as a basis for future studies in this area.