Analysis of the complete genome of peach chlorotic mottle virus: identification of non-AUG start codons, in vitro coat protein expression, and elucidation of serological cross-reactions

The entire genome of peach chlorotic mottle virus (PCMV), originally identified as Prunus persica cv. Agua virus (4N6), was sequenced and analysed. PCMV cross-reacts with antisera to diverse viruses, such as plum pox virus (PPV), genus Potyvirus, family Potyviridae; and apple stem pitting virus (ASPV), genus Foveavirus, family Flexiviridae. The PCMV genome consists of 9005 nucleotides (nts), excluding a poly(A) tail at the 3' end of the genome. Five open reading frames (ORFs) were identified with four untranslated regions (UTR) including a 5', a 3', and two intergenic UTRs. The genome organisation of PCMV is similar to that of ASPV and the two genomes share a nucleotide (nt) sequence identity of 58%. PCMV ORF1 encodes the replication-associated protein complex (Mr 241,503), ORF2-ORF4 code for the triple gene block proteins (TGBp; Mr 24,802, 12,370, and 7320, respectively), and ORF5 encodes the coat protein (CP) (Mr 42,505). Two non-AUG start codons participate in the initiation of translation: 35AUC and 7676AUA initiate translation of ORF1 and ORF5. In vitro expression with subsequent Western blot analysis confirmed ORF5 as the CP-encoding gene and confirmed that the codon AUA is able to initiate translation of the CP. Expression of a truncated CP fragment (Mr 39, 689) was demonstrated, and both proteins are expressed in vivo, since both were observed in Western blot analysis of PCMV-infected peach and Nicotiana occidentalis. The expressed proteins cross-reacted with an antiserum against ASPV. The amino acid sequences of the CPs of PCMV and ASPV CP share only 37% identity, but there are 11 shared peptides 4-8 aa residues long. These may constitute linear epitopes responsible for ASPV antiserum cross reactions. No significant common linear epitopes were associated with PPV. Extensive phylogenetic analysis indicates that PCMV is closely related to ASPV and is a new and distinct member of the genus Foveavirus.

Molecular Characterization, Phylogenetic Relationships, and Specific Detection of Peach mosaic virus

ABSTRACT Peach mosaic virus (PcMV) and Cherry mottle leaf virus (CMLV) are serologically related viruses that cause distinct diseases, have a different host range, and are vectored by different eriophyid mites. Sequence analysis of the genome of PcMV indicates that it is closely related genetically to CMLV but distinct, with similar genome organization and a member of the genus Trichovirus. The genome of PcMV consists of 7,988 nucleotides, excluding a poly(A) tail at the 3' end of the genome. Four putative open reading frames (ORF1 to 4) were identified coding for proteins of 216.3, 47.2, 21.7, and 15.7 kDa, respectively. Also, three noncoding regions were identified, including an intergenic region separating ORF3 and ORF4. The complete nucleotide sequence of PcMV shares 73% identity with CMLV. The CP amino acid sequence identity between isolates of PcMV ranged from 97 to 99% versus 83% identity when compared with the CP of CMLV. In vitro expression and subsequent western blot analysis confirmed ORF3 as encoding the CP gene of PcMV. Phylogenetic analysis supports classification of PcMV and CMLV as members of the genus Trichovirus. They are unique members of this genus with an extra ORF (ORF4). PcMV ORF4 appears to code for a putative nucleic acid-binding (NB) protein which has identity with the NB protein of CMLV and members of the genera Allexivirus, Carlavirus, and Vitivirus. PcMV and CMLV appear to be the products of recombination between members of the genus Trichovirus and a virus group containing the putative NB protein. Alternatively, PcMV and CMLV may represent the intact genome, with a deletion event producing members that lack ORF4. A reverse transcription-polymerase chain reaction procedure was developed for reliable and specific detection of PcMV. This will be an asset for stone fruit virus certification.

Bupropion sustained release (SR) for the treatment of hypoactive sexual desire disorder (HSDD) in nondepressed women

This article describes the results of the first report of bupropion sustained release (SR) in nondepressed females with hypoactive sexual desire disorder (HSDD). Eligible females entered a 4-week, single-blind, placebo baseline phase. Subjects, all of whom did not respond to placebo, continued in a single-blind active treatment phase where they received bupropion SR for up to 8 additional weeks. We assessed HSDD by using investigator ratings of sexual desire and sexual functioning. Of the 51 evaluable subjects who entered the active treatment phase, 29% responded to treatment with bupropion SR. Bupropion SR was generally well tolerated. Pending the results of further study, bupropion SR may offer a treatment option for women with HSDD.

Randomized study of CODE versus alternating CAV/EP for extensive-stage small-cell lung cancer: an Intergroup Study of the National Cancer Institute of Canada Clinical Trials Group and the Southwest Oncology Group

PURPOSE

To determine whether an intensive weekly chemotherapy regimen plus thoracic irradiation is superior to standard chemotherapy in the treatment of extensive-stage small-cell lung cancer (ESCLC).

PATIENTS AND METHODS

Patients with ESCLC were considered eligible for the study if they were younger than 68 years, had a performance status of 0 to 2, and were free of brain metastases. Patients were randomized to receive cisplatin, vincristine, doxorubicin, and etoposide (CODE) or alternating cyclophosphamide, doxorubicin, vincristine/etoposide and cisplatin (CAV/EP). Consolidative thoracic irradiation and prophylactic cranial irradiation were given to patients responding to CODE and according to investigator discretion on the CAV/EP arm.

RESULTS

The fidelity of drug delivery on both drug regimens was equal, and more than 70% of all patients received the intended protocol chemotherapy. Although rates of neutropenic fever were similar, nine (8.2%) of 110 patients on the CODE arm died during chemotherapy, whereas one (0.9%) of 109 patients died on the CAV/EP arm. Response rates after chemotherapy were higher (P =.006) with CODE (87%) than with CAV/EP (70%). However, progression-free survival (median of 0.66 years on both arms) and overall survival (median, 0.98 years for CODE and 0. 91 years for CAV/EP) were not statistically different.

CONCLUSION

The CODE regimen increased two-fold the received dose-intensity of four of the most active drugs in small-cell lung cancer compared with the standard CAV/EP regimen while maintaining an approximately equal total dose. Despite supportive care (but not routine prophylactic use of granulocyte colony-stimulating factor), there was excessive toxic mortality with the CODE regimen. The response rate with CODE was higher than that of CAV/EP, but progression-free and overall survival were not significantly improved. In view of increased toxicity and similar efficacy, the CODE chemotherapy regimen is not recommended for treatment of ESCLC.

A placebo-controlled comparison of the antidepressant efficacy and effects on sexual functioning of sustained-release bupropion and sertraline

Sexual dysfunction, a frequently reported side effect of many antidepressants, may result in patient dissatisfaction and noncompliance with treatment regimens. This paper describes the results of the first placebo-controlled comparison of the efficacy, safety, and effects on sexual functioning of sustained-release bupropion (bupropion SR) and the selective serotonin reuptake inhibitor sertraline. This randomized, double-masked, double-dummy, parallel-group, multicenter trial enrolled 360 patients with moderate-to-severe recurrent major depression. Patients were treated with bupropion SR 150 to 400 mg/d, sertraline 50 to 200 mg/d, or placebo for up to 8 weeks. Patients' depression and sexual functioning were assessed at weekly or biweekly clinic visits; safety was assessed by regular monitoring of adverse events, vital signs, and body weight. Treatment groups were similar at baseline in terms of age, sex, and race, and most patients had a diagnosis of moderate uncomplicated depression. Patients treated with bupropion SR or sertraline showed similar improvements on all efficacy measures; both active treatments were superior to placebo in improving scores on all rating scales for depression at various time points. Significantly more patients treated with sertraline experienced orgasmic dysfunction throughout the study than did patients treated with bupropion SR or placebo (P < 0.001). Headache was the most frequently reported adverse event in all 3 treatment groups and occurred with similar frequency in each group (30% to 40%). Nausea (31%), diarrhea (26%), insomnia (18%), and somnolence (17%) occurred in significantly more patients in the sertraline group than in the bupropion SR group (18%, 7%, 13%, and 3%, respectively) and the placebo group (10%, 11%, 4%, and 6%, respectively). Dry mouth occurred more frequently with bupropion SR (19%) than with sertraline (14%) or placebo (12%), although the differences were not significant. Changes in vital signs were similar in all groups. Similar (small, but not statistically significant) decreases in mean body weight were seen in both the bupropion SR (-1.06 kg) and sertraline (-0.79 kg) groups, whereas the placebo group experienced a minor increase (0.21 kg). Although bupropion SR and sertraline were similarly well tolerated and effective in the treatment of depression, sertraline treatment was more often associated with sexual dysfunction and certain other adverse events compared with bupropion SR and placebo. Therefore, bupropion SR may be an appropriate choice as an antidepressant for the treatment of sexually active patients.

Rats' memory for serially presented novel flavours: evidence for non-spatial primacy effects

Four experiments examined the effects of serially presenting a number of novel flavours to rats on their subsequent consumption of those flavours. In Experiments 1-4, rats were orally infused with 0.5 ml of flavour over 30 sec for each of five flavours in the exposure phase of the experiment. In these studies, primacy and recency effects emerged, the size of the primacy effect being related to the length of the retention interval, which varied from zero to twenty-four hours. Thus, both primacy and recency effects can be generated using non-spatial stimuli with rats.

A short-term in vitro drug-screening assay for cancer chemotherapy

In this short-term in vitro assay for detection of tumor cell sensitivity to drugs, we have replaced the traditional soft-agar colony-forming assay with the measurement of DNA synthesis, to determine the cell renewal capability of the tumor cell population. The tumor cells are treated with drugs and cultured for five days. During the last 12--18 h of culture the cells are pulsed with [3H]thymidine, then harvested for scintillation counting. The effects of drugs are expressed as the percentage of DNA synthesis as compared with that of the control. When the % DNA synthesis is less than 40%, the drug is considered to be effective. So far we have studied tumor cells from multiple myeloma, non-Hodgkin's lymphoma, and carcinoma of lung, breast, ovary, stomach, and bladder. The overall negative predictive value is 1.0. The results are available within five days, compared with 21--28 days for completion of soft-agar assays; fewer cells are required; and the process is semiautomated.