Blinded independent central review of progression in cancer clinical trials: results from a meta-analysis.

PURPOSE: Progression free survival (PFS) is increasingly used as a primary end-point in oncology clinical trials. This paper provides observations and recommendations on the use of a blinded independent central review (BICR) for progression. PATIENTS AND METHODS: The findings and recommendations are based on extensive simulations and a meta-analysis based on 27 previously conducted randomised phase III trials with BICR performed by the Pharmaceutical Research and Manufacturers Association (PhRMA) sponsored PFS Independent Review Working Group. RESULTS: Results of the meta-analysis demonstrate a strong correlation between LE and BICR estimates of treatment effect (R=0.947). Further, differences between treatment groups in discordance rates predict the differences between LE and BICR estimates of treatment effect supporting the use of a sample-based BICR on a subgroup of patients. CONCLUSION: The meta-analysis demonstrates that local evaluation (LE) provides a reliable estimate of the treatment effect with little evidence for systematic evaluation bias. Therefore, when a trial is blinded or a large effect on PFS is observed a BICR may not be warranted. When a BICR is warranted, a sample-based BICR may provide a reduction in operational complexity without compromising the credibility of trial results. While for large trials that are not adequately blinded a sample-based BICR may be recommended. A full BICR should be considered in the case of smaller trials or in situations in which there is a particular need to increase the confidence in the LE results.

Research outcomes and recommendations for the assessment of progression in cancer clinical trials from a PhRMA working group.

PURPOSE: Progression free survival (PFS) is increasingly used as a primary end-point in oncology clinical trials. This paper provides recommendations for optimal trial design, conduct and analysis in situations where PFS has the potential to be an acceptable end-point for regulatory approval. PATIENTS AND METHODS: These recommendations are based on research performed by the Pharmaceutical Research and Manufacturers Association (PhRMA) sponsored PFS Working Group, including the re-analysis of 28 randomised Phase III trials from 12 companies/institutions. RESULTS: (1) In the assessment of PFS, there is a critical distinction between measurement error that results from random variation, which by itself tends to attenuate treatment effect, versus bias which increases the probability of a false negative or false positive finding. Investigator bias can be detected by auditing a random sample of patients by blinded, independent, central review (BICR). (2) ITT analyses generally resulted in smaller treatment effects (HRs closer to 1) than analyses that censor patients for potentially informative events (such as starting other anti-cancer therapy). (3) Interval censored analyses (ICA) are more robust to time-evaluation bias than the log-rank test. CONCLUSION: A sample based BICR audit may be employed in open or partially blinded trials and should not be required in true double-blind trials. Patients should be followed until progression even if they have discontinued treatment to be consistent with the ITT principle. ICAs should be a standard sensitivity analysis to assess time-evaluation bias. Implementation of these recommendations would standardize and in many cases simplify phase III oncology clinical trials that use a PFS primary end-point.

Effects of deoxynivalenol on content of chloroplast pigments in barley leaf tissues.

To understand further the role of deoxynivalenol (DON) in development of Fusarium head blight (FHB), we investigated effects of the toxin on uninfected barley tissues. Leaf segments, 1 to 1.2 cm long, partially stripped of epidermis were floated with exposed mesophyll in contact with DON solutions. In initial experiments with the leaf segments incubated in light, DON at 30 to 90 ppm turned portions of stripped tissues white after 48 to 96 h. The bleaching effect was greatly enhanced by addition of 1 to 10 mM Ca(2+), so that DON at 10 to 30 ppm turned virtually all stripped tissues white within 48 h. Content of chlorophylls a and b and of total carotenoid pigment was reduced. Loss of electrolytes and uptake of Evans blue indicated that DON had a toxic effect, damaging plasmalemmas in treated tissues before chloroplasts began to lose pigment. When incubated in the dark, leaf segments also lost electrolytes, indicating DON was toxic although the tissues remained green. Thus, loss of chlorophyll in light was due to photobleaching and was a secondary effect of DON, not required for toxicity. In contrast to bleaching effects, some DON treatments that were not toxic kept tissues green without bleaching or other signs of injury, indicating senescence was delayed compared with slow yellowing of untreated leaf segments. Cycloheximide, which like DON, inhibits protein synthesis, also bleached some tissues and delayed senescence of others. Thus, the effects of DON probably relate to its ability to inhibit protein synthesis. With respect to FHB, the results suggest DON may have multiple roles in host cells of infected head tissues, including delayed senescence in early stages of infection and contributing to bleaching and death of cells in later stages.

Distribution of Mycelial Colonies and Lesions in Field-Grown Barley Inoculated with Fusarium graminearum.

ABSTRACT External surfaces of barley florets have thick-walled epidermal cells resistant to direct penetration by the head blight pathogen, Fusarium graminearum. Surfaces within the floral cavity have thin-walled, susceptible cells. How the fungus gains access to the floral cavity, causing head blight, has not been determined. To investigate pathways of entry, field-grown plants were sprayed with macroconidial inoculum after heads emerged from the flag leaf sheath and then were mist irrigated daily in the morning and evening. On selected days, 1 to 8 days after inoculation (DAI), 80 to 190 florets per day were harvested, dissected, and examined for presence and location of mycelial colonies. At 1 to 12 DAI, 57 to 100 florets likewise were examined for lesions. Patterns of colonization indicated that the fungus entered florets principally through crevices between the overlapping lemma and palea or through the apical floret mouth. The crevices were open for entry until approximately 8 days after heads emerged. Most florets had mycelial colonies on the external surface in a sheltered pocket near the base of the ventral furrow of the palea. Mycelia spread laterally from the furrow to the crevice between lemma and palea. Anther colonization had only a minor role in invasion of florets. Hyphal penetration of stomates was not seen. Lesions usually developed first within 3 mm of the floret apex or 3 mm of the floret base. Within florets, lesions often were contiguous between lemma and palea, palea and caryopsis, or in all three floret parts. However, lesions in the caryopsis developed later and were fewer in number than in the lemma and palea and always were associated with lesions in the palea. The results show the importance of initial mycelial colonization of floret outer surfaces, pathways of entry via lemma or palea crevices or floret mouth, and spread of lesions within the floret at interfaces between lemma, palea, and caryopsis.

Spore dimensions of Puccinia species of cereal hosts as determined by image analysis.

Digital image analysis was used to measure dimensions of spores produced by Puccinia coronata, P. graminis, P. hordei, P. recondita, P. striiformis and P. triticina. Included were teliospores, basidiospores, urediniospores and, except for P. striiformis, pycniospores and aeciospores. Length, width and projection area of spores were measured with NIH Image or Scion software. By using limits on size, spores were automatically selected and measured, except for teliospores, which required manual elimination of the pedicel and separation of images of adhering spores. Length and width were determined as the major and minor axes of the best fitting ellipse for each spore. This procedure gave values for length and width close to results obtained with an ocular micrometer. Projection area was determined as the number of pixels within spore boundaries multiplied by the area represented by each pixel, giving values that are not feasible to obtain accurately with an ocular micrometer. Of the species studied, spores of P. recondita had the largest dimensions, P. triticina had the smallest. The rank of the six species based on increasing width, length or projection area was almost the same, using each spore type except pycniospores. Generally, differences of 5% in a given spore dimension between two species were significant. Differences between species were greater with basidiospores and aeciospores than with other spore types. Teliospores were unique in that length and width were negatively correlated, resulting in less variation in area than in length or width. The results indicate that image analysis is useful for measuring spore dimensions, that projection area of spores is a useful added parameter for characterizing rust species and that dimensions of teliospores, basidiospores, aeciospores and urediniospores each are potentially useful for differentiating species.

Morphology, life cycle biology, and DNA sequence analysis of rust fungi on garlic and chives from california.

ABSTRACT In the late 1990s, commercial garlic fields in California (CA) were devastated by an outbreak of rust caused by Puccinia allii. We compared collections of the pathogen from garlic (Allium sativum) and chives (A. schoenoprasum) in central CA and Oregon (OR) to collections from garlic and leek (A. porrum and A. ampeloprasum) in the Middle East. Teliospores from the CA and OR collections were smaller in length, width, and projected cross-sectional area compared with collections from the Middle East. CA and OR collections had a shortened life cycle, in which pycnia and aecia were not formed. Germinating teliospores produced a two-celled promycelium, resulting in two basidiospores, each initially with two nuclei, indicating that this rust was homothallic. In addition, the morphology of the substomatal vesicles was different between the CA-OR (fusiform) and the Middle Eastern (bulbous) collections. DNA sequence analysis of the nuclear ribosomal internal transcribed spacer region showed that the CA and OR rust collections formed a well-supported cluster distinct from the Middle Eastern and European samples. These results suggest that the rust on garlic and chives in CA and OR is a different species than the rust fungus on garlic and leek in the Middle East.

A comparison of the efficacy and safety of mupirocin cream and cephalexin in the treatment of secondarily infected eczema.

The efficacy and safety of mupirocin calcium cream were compared with those of oral cephalexin in the treatment of secondarily infected eczema. In this multicentre, double-blind, double-dummy study, 159 patients with secondarily infected eczema (suitable for treatment with topical antimicrobials) and a total skin infection rating scale score of 8 or more were randomized to receive either topical mupirocin cream three times daily or oral cephalexin, 250 mg four times daily, for 10 days (intent-to-treat group). Clinical success (per-protocol group), defined in part as a patient with a response of improvement in the skin infection rating scale, was similar in the two groups: 89% for mupirocin (n = 44) and 82% for cephalexin (n = 38) [P = 0.29; 95% confidence interval (-8.4%, 22.5%)]. Bacteriological success (intent-to-treat group), defined as a patient with a response of eradication, improvement or colonization of bacteria at the end of therapy, however, was significantly higher for mupirocin [50% and 28% in the mupirocin (n = 48) and cephalexin (n = 47) groups, respectively; P=0.005]. Mupirocin cream was as well tolerated as cephalexin; 9% and 13% of patients reported adverse events related or possibly related to study medication in the mupirocin and cephalexin groups, respectively. The most common adverse events overall were diarrhoea and nausea. Mupirocin cream applied three times daily is as effective clinically and superior bacteriologically compared with oral cephalexin given four times daily in the treatment of secondarily infected eczema of limited depth and severity. Mupirocin cream is as well tolerated as oral cephalexin, and more patients prefer the topical regimen, which should improve patient compliance.

Double-blind, randomized, parallel-group study on the efficacy and safety of oral granisetron and oral ondansetron in the prophylaxis of nausea and vomiting in patients receiving hyperfractionated total body irradiation.

The efficacy and safety of granisetron and ondansetron for the prophylaxis of nausea and vomiting resulting from hyperfractionated total body irradiation (TBI) were assessed. Thirty-four patients randomly received double-blind, oral granisetron (2 mg, 1 h before first daily fraction of radiation) or ondansetron (8 mg, 1.5 h prior to each fraction of TBI). Ninety patients who received the same TBI regimen prior to bone marrow transplantation (BMT), but no 5-HT3-receptor antagonist, were identified and comprised the historical control group. By design, this study was only powered to show a difference between each of the active treatment groups and the historical control group. Significantly more patients given granisetron (33.3%) or ondansetron (26.7%) had zero emetic episodes over 4 days, the primary efficacy end point, than those in the historical control group (0%) (P < 0.01; intent-to-treat). Secondary efficacy end points were also evaluated. During the first 24 h, significantly more patients taking granisetron (61.1%) or ondansetron (46.7%) had zero emetic episodes than patients in the historical control group (6.7%) (P < 0.01). Complete emetic control (no emesis or rescue antiemetic) over 4 days was more frequent in patients taking granisetron (27.8%) or ondansetron (26.7%) compared with the historical control group (0%) (P < 0.01). Significantly fewer patients taking granisetron (18/18), but not those taking ondansetron (12/15), experienced more than five emetic episodes during the 4 days of the study compared with the historical control group (40/90; P < 0.01). Oral granisetron and ondansetron are safe and effective for the prevention of nausea and vomiting resulting from TBI.

Fungal development and induction of defense response genes during early infection of wheat spikes by Fusarium graminearum.

Fusarium head blight (FHB) of wheat is a crippling disease that causes severe economic losses in many of the wheat-growing regions of the world. Temporal patterns of fungus development and transcript accumulation of defense response genes were studied in Fusarium graminearum-inoculated wheat spikes within the first 48 to 76 h after inoculation (hai). Microscopy of inoculated glumes revealed that the fungus appeared to penetrate through stomata, exhibited subcuticular growth along stomatal rows, colonized glume parenchyma cells, and sporulated within 48 to 76 hai. No major differences in the timing of these events were found between Sumai 3 (resistant) and Wheaton (susceptible) genotypes. In complementary experiments, RNA was extracted from spikes at several time intervals up to 48 hai and temporal expression patterns were determined for defense response genes encoding peroxidase, PR-1, PR-2 (beta-1,3-glucanase), PR-3 (chitinase), PR-4, and PR-5 (thaumatin-like protein). In both genotypes, transcripts for the six defense response genes accumulated as early as 6 to 12 hai during F. graminearum infection and peaked at 36 to 48 hai. Greater and earlier PR-4 and PR-5 transcript accumulation was observed in Sumai 3, compared with Wheaton. Our results show that the timing of defense response gene induction is correlated with F. graminearum infection.

Mupirocin cream is as effective as oral cephalexin in the treatment of secondarily infected wounds.

BACKGROUND: Topical antimicrobials have been considered for treatment of secondarily infected wounds because of the potential for reduced risk of adverse effects and greater patient convenience. We compared mupirocin cream with oral cephalexin in the treatment of wounds such as small lacerations, abrasions, or sutured wounds. METHODS: In 2 identical randomized double-blind studies, 706 patients with secondarily infected wounds (small lacerations, abrasions, or sutured wounds) received either mupirocin cream topically 3 times daily or cephalexin orally 4 times daily for 10 days. RESULTS: Clinical success at follow-up was equivalent in the two groups: 95.1% and 95.3% in the mupirocin cream and the cephalexin groups, respectively (95% confidence interval [CI], -4.0% to 3.6%; P = .89). The intention-to-treat success rate was 83% in both groups. Bacteriologic success at follow-up was also comparable: 96.9% in the mupirocin cream and 98.9% in the cephalexin groups (95% CI, -6.0% to 2.0%; P = .22). The occurrence of adverse experiences related to study treatment was similar for the 2 groups, with fewer patients in the mupirocin cream group reporting diarrhea (1.1% vs 2.3% for cephalexin). CONCLUSIONS: Mupirocin cream applied topically 3 times daily is as effective as oral cephalexin given 4 times daily for the treatment of secondarily infected wounds and was well tolerated.

Paroxetine treatment of generalized social phobia (social anxiety disorder): a randomized controlled trial.

CONTEXT: The generalized type of social phobia (social anxiety disorder) is a severe and often disabling form of social anxiety that affects approximately 5% of the general population. Earlier research has shown monoamine oxidase inhibitors or benzodiazepines to be effective in treating this condition, but neither has achieved widespread use. OBJECTIVE: To compare the efficacy of paroxetine, a selective serotonin reuptake inhibitor, with placebo in adults with generalized social phobia. DESIGN: Twelve-week, multicenter, randomized, double-blind trial. SETTING: Thirteen centers across the United States and 1 in Canada. PARTICIPANTS: Between April 13, 1995, and February 28, 1996, 187 persons meeting Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition criteria for generalized social phobia were randomized (and 183 returned for at least 1 efficacy assessment) to treatment. INTERVENTION: After a 1-week, single-blind, placebo, run-in period, patients received a double-blind, 11-week course of either paroxetine or matching-image placebo. The initial daily dosage of paroxetine (or placebo) was 20 mg with increases of 10 mg/d weekly (flexible dosing to a maximum of 50 mg/d) permitted after the second week of treatment. MAIN OUTCOME MEASURES: Number of responders based on the Clinical Global Impression Global Improvement Item ("much improved" or "very much improved"); mean change from baseline on the Liebowitz Social Anxiety Scale total score. RESULTS: Fifty (55.0%) of 91 persons taking paroxetine and 22 (23.9%) of 92 persons taking placebo were much improved or very much improved at the end of treatment (odds ratio [OR], 3.88; 95% confidence interval [CI], 2.81-5.36). Mean Liebowitz Social Anxiety Scale total scores were reduced by 39.1% (the mean baseline score of 78.0 declined by a mean of 30.5 points at follow-up) in the paroxetine group compared with 17.4% (the mean baseline score of 83.5 declined 14.5 points at follow-up) in the placebo group, a difference of 21.7% (95% CI, 8.7%-34.7%) favoring paroxetine. CONCLUSIONS: Paroxetine is an effective treatment for patients with generalized social phobia. Short-term (ie, 11-week) treatment results in substantial and clinically meaningful reductions in symptoms and disability. Future research should test whether these may be further reduced by extended treatment or supplementation with specific educational-cognitive-behavioral techniques.

Single-dose oral granisetron has equivalent antiemetic efficacy to intravenous ondansetron for highly emetogenic cisplatin-based chemotherapy.

PURPOSE: To compare the antiemetic efficacy of a single dose of an oral antiemetic (granisetron 2 mg) with a single dose of an intravenous (i.v.) antiemetic (ondansetron 32 mg) given before cisplatin-based chemotherapy. PATIENTS AND METHODS: This was a multicenter, randomized, double-blind, parallel-group study. Patients (N = 1,054) scheduled to receive cisplatin (> or = 60 mg/m2)-based chemotherapy were randomized to receive either 2 mg of oral granisetron tablets 1 hour before chemotherapy (n = 534) or i.v. ondansetron (32 mg) 30 minutes before chemotherapy (n = 520). The primary efficacy end point was total control (no emesis, no nausea, and no use of antiemetic rescue medication) over the initial 24 hours after the start of chemotherapy. Dexamethasone or methylprednisolone were permitted, but not required, as concomitant prophylactic antiemetics. RESULTS: Total control was equivalent 24 hours after cisplatin chemotherapy for single-dose oral granisetron (54.7%) and i.v. ondansetron (58.3%) (95% confidence interval [CI], -9.6 to 2.4). Similar proportions of patients remained nausea-free in the granisetron group (55.4%) and the ondansetron group (59%) (95% CI, -9.6 to 2.4). The rate of complete control of emesis was 61.2% in the granisetron group and 67.1% in the ondansetron group (95% CI, -11.7 to -0.1). Both treatment regimens were well tolerated, with similar patterns of adverse reactions, generally of a mild degree. The most common side effects included constipation (14%), headache (15%), and diarrhea (10%). CONCLUSION: Oral granisetron, administered as a single 2-mg dose, provided equivalent total antiemetic control when compared with i.v. ondansetron (32 mg) in patients who received highly emetogenic, cisplatin-based chemotherapy.

Comparison of single-dose oral granisetron versus intravenous ondansetron in the prevention of nausea and vomiting induced by moderately emetogenic chemotherapy: a multicenter, double-blind, randomized parallel study.

PURPOSE: The antiemetic effectiveness and safety of single-dose oral granisetron were compared with intravenous (I.V.) ondansetron in chemotherapy-naive patients who received moderately emetogenic chemotherapy. PATIENTS AND METHODS: In this double-blind, parallel-group study, patients naive to emetogenic chemotherapy (N = 1,085) who were scheduled to receive cyclophosphamide- (500 to 1,200 mg/m2) or carboplatin (> or = 300 mg/m2) based chemotherapy, were randomized to receive either oral granisetron (n = 542) or I.V. ondansetron (n = 543). Efficacy assessments included the proportion of patients in each treatment group with total control over the 24 and 48 hours following chemotherapy initiation, as well as incidence and severity of nausea and emesis and use of antiemetic rescue medication. Prophylactic corticosteroids were allowed. Safety assessment was based on patients' reports of adverse experiences. RESULTS: Approximately 80% of patients received prophylactic corticosteroids. Single-dose oral granisetron (2 mg) and I.V. ondansetron (32 mg) resulted in equivalent levels of total emetic control during the first 48 hours after chemotherapy. The proportion of nausea- and emesis-free patients at 24 and 48 hours were also approximately equivalent. The most commonly reported adverse experiences were headache, asthenia, and constipation. More patients who received ondonsetron than granisetron reported dizziness (9.6% v 5.4%, respectively; P = .011) and abnormal vision (4.2% v 0.6%, respectively; P < .001). CONCLUSION: A single oral dose of granisetron (2 mg) resulted in equivalent levels of antiemetic protection as I.V. ondansetron (32 mg). Both agents were well tolerated, although more dizziness and abnormal vision were reported with ondansetron. Because the two antiemetic regimens exhibited equivalent efficacies, additional factors such as convenience and cost of therapy should be considered.

Double-blind, fixed-dose, placebo-controlled study of paroxetine in the treatment of panic disorder.

OBJECTIVE: This study was designed to determine the minimum paroxetine dose effective for treating panic disorder. METHOD: Of 425 patients with DSM-III-R panic disorder with or without agoraphobia who underwent a 2-week drug-free screening period, 278 patients were randomly assigned to double-blind treatment with a 10-week course of placebo or paroxetine at a dose of 10, 20, or 40 mg/day. RESULTS: At 40 mg/day, paroxetine was superior to placebo across the majority of outcome measures. Despite a mean of 9.5 to 11.6 full panic attacks during the screening period, 86.0% of the patients taking 40 mg of paroxetine, 65.2% of those taking 20 mg, 67.4% of those taking 10 mg, and 50.0% of the placebo-treated patients were free of full panic attacks during the 2 weeks ending at week 10. The 40-mg paroxetine group experienced significantly greater global improvement than the placebo group and significantly greater improvement in frequency of full and limited-symptom panic attacks, intensity of full panic attacks, phobic fear, anxiety, and depressive symptoms, usually evident by week 4. All doses of paroxetine were well tolerated, and adverse effects were consistent with those associated with selective serotonin reuptake inhibitors. CONCLUSIONS: Paroxetine is an effective and well-tolerated short-term treatment of panic disorder. The minimum dose demonstrated to be significantly superior to placebo was 40 mg/day, although some patients did respond at lower doses.

Isolation and expression of a host response gene family encoding thaumatin-like proteins in incompatible oat-stem rust fungus interactions.

Four cDNA clones (corresponding to tlp-1, -2, -3, and -4 genes) encoding thaumatin-like (TL), pathogenesis-related proteins were isolated from oat (Avena sativa) infected by an incompatible isolate Pga-1H of the oat stem rust fungus (Puccinia graminis f. sp. avenae). All four cDNA clones contained an open reading frame predicted to encode a 169-amino acid polypeptide with a signal peptide of 21 amino acids at the N-terminus, suggesting that these proteins are transported through a secretory pathway. The amino acid sequences revealed high homology among the four cDNA clones, 80 to 99% identity and 86 to 100% similarity. The tlp genes and several TL protein genes of certain cereals are clustered into a small group that is phylogenetically separate from the major group of TL protein genes of several plant species. In plants infected with the incompatible isolate Pga-1H, or an inappropriate isolate Pgt-8D of P. graminis f. sp. tritici, high levels of tlp gene transcripts accumulated at 42 to 48 h AI and thereafter when hypersensitive host cell death occurred and hyphal growth was inhibited, whereas in plants infected with a compatible isolate Pga-6A, relatively lower amounts of transcripts were detected. Overall, transcript levels were higher with tlp-1 than with the three other genes. Spray with a light mineral oil used as a spore carrier induced transient expression of tlp-1, -2, and -3 genes at 16 to 30 h AI which obscured the initial induction of the tlp genes in response to infection by the pathogens. In contrast, tlp-4 was induced very little by oil spray, so that induction was clearly observed in response to either compatible, incompatible, or inappropriate isolates at 24 to 30 h AI. Wounding leaves by either slicing or puncturing them strongly induced tlp-1 and tlp-3, moderately induced tlp-2, but had no effect on tlp-4. Taken together, the results showed that tlp genes displayed differential responses to oil spray, mechanical wounding, and pathogen infection and that the expression of tlp genes, especially tlp-1, in oat is associated with resistance reactions in response to infection by incompatible and inappropriate isolates of the stem rust fungi.

A double-blind, randomized study to provide safety information on switching fluoxetine-treated patients to paroxetine without an intervening washout period.

BACKGROUND: The long elimination half-lives of fluoxetine and norfluoxetine, the active metabolite of fluoxetine, are of potential consequence when alternative antidepressant agents are introduced after the termination of fluoxetine therapy. It is not known whether paroxetine, an antidepressant agent in the same pharmacologic class as fluoxetine, can be substituted for fluoxetine without the need for an intervening washout period. The objective of this trial was to assess the tolerability of an immediate switch from fluoxetine to paroxetine therapy. METHOD: Patients who were treated for moderate to moderately severe major depressive disorder (DSM-III-R 296.2 or 296.3) with a stable dose of fluoxetine for a minimum of 6 weeks' duration were randomized in a double-blind fashion to one of two treatment groups. One group (N = 123) was started on 20 mg of paroxetine daily the morning after their last dose of fluoxetine, and the other group (N = 119) was started on 20 mg of paroxetine daily following a 2-week placebo-washout period. Patient visits were scheduled at weekly intervals for a total of 4 weeks. Adverse experience monitoring was conducted at each visit. RESULTS: There was no difference in the proportion of patients who discontinued prematurely from the trial due to an adverse experience. Eight patients in the immediate-switch group and 6 patients in the placebo-washout group withdrew from the trial in response to an adverse experience (p = .63, chi-square). The overall profile of adverse experiences was similar in the two treatment groups over the 4-week period. The incidence of adverse experiences in the first 2 weeks following the initiation of paroxetine was generally lower in the group with the intervening 2-week placebo-washout period. CONCLUSION: The immediate switch from fluoxetine to paroxetine was as well tolerated as the switch to paroxetine after a 2-week placebo-washout period.

Molecular cloning and analysis of abundant and stage-specific mRNAs from Puccinia graminis.

To characterize highly expressed mRNAs from germinated urediniospores of Puccinia graminis f. sp. tritici, we isolated 68 cDNA clones of abundant mRNA species belonging to at least six homology groups. The two most abundant homology groups, HG1 and HG2, contained 54 of the 68 cDNA clones and accounted for 2.4 and 0.6% of the poly(A)+ RNA in germinated urediniospores, respectively. By sampling different developmental stages of the uredinial cycle, we showed that the uam transcript, corresponding to HG2, accumulated in all stages of hyphal and urediniospore development, whereas the accumulation of usp transcript, corresponding to HG1, was specific to the sporulation stage. Southern blot analysis indicated that usp is a small gene family consisting of three to four members. Sequence analysis of 10 cDNA clones indicated that two different members of the usp gene family were expressed in germinated urediniospores. This gene family encodes small hydrophobic polypeptides of 113 amino acids with an unusual amino acid composition, in that alanine, glycine, leucine, and proline represent 48% of the protein. These polypeptides are predicted to be localized extracellular because they contain a putative signal sequence and may be functionally related to hydrophobins, a family of small hydrophobic proteins abundantly expressed during sporulation in Schizophyllum commune and Aspergillus nidulans. The uam and usp genes deserve further investigation, including isolation of genomic clones. The regulatory regions of the uam gene, which is highly expressed in hyphae, may be useful in the construction of a transformation vector for rust fungi.

Callus formation and plant regeneration from somatic embryos of oat (Avena sativa L.).

Globular-stage somatic embryos were isolated by vortexing friable, embryogenic callus of oat (Avena sativa L.) followed by fractionation based on size. Somatic embryos were most frequently found in the 300-380 µm size fraction. Friable, embryogenic callus was reinitiated from 55% of isolated somatic embryos. Fertile plants were regenerated from 22% of isolated somatic embryos. Reinitiation of callus from somatic embryos and growth of friable, embryogenic callus was inhibited by the selective agents G418 and methotrexate. These results suggest that somatic embryos isolated from friable, embryogenic callus of oat may be useful totipotent targets for particle acceleration-mediated transformation.

Pontentiometric cyanine dyes are sensitive probes for mitochondria in intact plant cells : kinetin enhances mitochondrial fluorescence.

Selected fluorescent dyes were tested for uptake by mitochrondria in intact cells of barley, maize, and onion. The cationic cyanine dye 3,3'-diheptyloxacarbocyanine iodide [DiOC(7)(3)] accumulated in mitochondria within 15 to 30 minutes without appreciable staining of other protoplasmic constituents. The number, shape, and movement of the fluorescent mitochondria could be seen readily, and the fluorescence intensity of the mitochondria could be monitored with a microscope photometer. Fluorescence was eliminated in 1 to 5 minutes by the protonophore carbonyl cyanide m-chlorophenylhydrazone (CCCP) indicating that maintenance of dye concentration was dependent on the inside-negative transmembrane potential maintained by functional mitochondria. Fluorescence of prestained mitochondria was enhanced within 5 to 10 minutes after addition of 0.1 millimolar kinetin to cells. The fluorescence in kinetintreated cells was dissipated by CCCP. These results suggest that kinetin interacted with respiratory processes resulting in higher potential across the mitochondrial membrane.