Developing an innovative national ACP-OSCE program in Taiwan: a mixed method study

OBJECTIVES

To evaluate the process and the comprehensiveness of advance care planning (ACP), we designed a national ACP-OSCE (Objective Structured Clinical Examination) program.

METHODS

The program was designed as a 40-minute OSCE test. Participants were categorized as different ACP team members to illustrate realistic scenarios. Preceptors were asked to observe ACP professionals' actions, responses, and communication skills during ACP with standardized patients (SP) through a one-way mirror. Participants' communication skills, medical expertise, legal knowledge, empathetic response and problem-solving skills of ACP were also self-evaluated before and after OSCE. Thematic analysis was used for qualitative analysis.

RESULTS

In Nov 2019, a total of 18 ACP teams with 38 ACP professionals completed the ACP-OSCE program, including 15 physicians, 15 nurses, 5 social workers, and 3 psychologists. After the ACP-OSCE program, the average score of communication skills, medical expertise, legal knowledge, empathetic response, ACP problem-solving all increased. Nurses felt improved in medical expertise, legal knowledge, and problem-solving skills, psychologists and social workers felt improved in legal knowledge, while physicians felt no improved in all domain, statistically. Thematic analysis showed professional skills, doctoral-patient communication, benefit and difficulties of ACP were the topics which participants care about. Meanwhile, most participants agreed that ACP-OSCE program is an appropriate educational tool.

CONCLUSION

This is the first national ACP-OSCE program in Asia. We believe that this ACP-OSCE program could be applied in other countries to improve the ACP process and quality.

Case report: Malignant transformation of ovarian endometrioma during long term use of dienogest in a young lady

Endometriosis is a benign disease, which is also regarded as a precursor to ovarian malignancy. Dienogest is a progestin treatment for endometriosis with efficacy and tolerability. A 35-year-old Taiwanese lady with ovarian endometrioma had taken dienogest for the last 5 years. During sonographic follow-up, surgery was suggested owing to suspicious of malignant transformation of ovarian endometrioma. While she hesitated and turned to receive two cycles of oocyte retrieval because of nulliparity. Meanwhile, more papillary growth in the ovarian endometrioma with intratumor flow was found during follow-up. Laparoscopic enucleation was performed later, and pathology revealed clear cell carcinoma with peritoneal involvement, at least FIGO stage IIB. She then underwent debulking surgery to grossly no residual tumor and received adjuvant chemotherapy with no tumor recurrence in post-operative 17-months follow-up. Considering fertility preservation, conservative treatment of ovarian endometrioma is typically indicated for those women who have not yet completed childbearing. However, malignant transformation may still occur despite long-term progestin treatment. Therefore, careful image follow-up is still indispensable.

Maintenance Chemotherapy in Patients with Platinum-Sensitive Relapsed Epithelial Ovarian Cancer after Second-Line Chemotherapy

(1) Background: Our aim was to evaluate the efficacy and adverse effects of maintenance chemotherapy in platinum-sensitive recurrent epithelial ovarian cancer after second-line chemotherapy. (2) Methods: A total of 72 patients from a single institute who had been diagnosed with platinum-sensitive recurrent ovarian cancer and had experienced either complete or partial response after six cycles of second-line chemotherapy were divided into a standard group (n = 31) with six cycles or a maintenance group (n = 41) with more than six cycles. We then compared patient characteristics and survival outcomes between these two groups. (3) Results: In all patients, after primary management for the first recurrence, the maintenance group showed worse survival outcomes. Patients who had not undergone either surgery or radiotherapy were divided into complete response and partial response groups after six cycles of chemotherapy. In patients with partial response, maintenance chemotherapy led to a significant improvement in PFS (median, 3.6 vs. 6.7 months, p = 0.007), but no significant change in in OS. The median cycle number of maintenance chemotherapy was four. (4) Conclusions: Maintenance chemotherapy may still play an important role in patients with platinum-sensitive recurrent ovarian cancer, particularly in selected patient groups.

The Current Trend of Fertility Preservation in Patients with Cervical Cancer

Although the incidence of most cancers increases with age, a considerable number of patients receive a diagnosis of cancer during their reproductive years. Young women wishing to get pregnant after cancer treatment should be provided consultation for fertility preservation and possible options. In patients with cervical cancer, hysterectomy is often inevitable because the uterus is located too close to the cervix. For young patients with cervical cancer who desire to get pregnant and whose lesion is confined to the cervix, sparing the uterus and, partially, the cervix should be prioritized as much as possible, while simultaneously ensuring favorable oncologic outcomes. In this review, we explore how to choose an adequate fertility-preserving procedure to achieve a balance between favorable oncologic outcomes and fertility and management during pregnancy after a radical trachelectomy in women with early-stage cervical cancer. For patients who require hysterectomy or radiation, evaluation of the ovarian condition and laparoscopic ovarian transposition followed by the use of artificial reproduction techniques and pregnancy by surrogacy should be discussed as options to achieve a successful pregnancy.

Long-term outcome of minimally invasive staging surgery for clinical stage I endometrial cancer: A single institute experience in Taiwan

BACKGROUND

Endometrial cancer is the most common gynecological cancer in developed countries. With recent advances in equipment and knowledge, minimally invasive surgery (MIS) is widely accepted for the treatment of endometrial cancer. This study had the largest number of cases to date in Taiwan, comparing outcomes between MIS and laparotomy staging surgery using real-world data with long-term follow-up.

METHODS

We retrospectively reviewed patients with clinical stage 1 endometrial cancer from 2009 to 2020 in our institute. All patients underwent comprehensive surgical staging procedures by MIS or laparotomy. The safety, morbidity, progression-free survival (PFS), and overall survival (OS) rates of the two groups were compared. Clinical and pathologic factors were compared with Chi-square and Fisher Exact test. PFS and OS were estimated by the Kaplan-Meier method. Differences between survival curves were analyzed using the log-rank test. A p value of <0.05 was considered statistically significant. Using Cox proportional hazards models, all factors found to be significantly associated with risk of recurrence on univariate analyses were then assessed together through multivariable models, resulting in a final oncologic outcome between MIS and laparotomy.

RESULTS

A total of 665 cases (412 cases in MIS group and 253 cases in laparotomy group) were enrolled for data analysis. Median operation time was shorter in MIS group (244 and 265 minutes, p < 0.001). Median blood loss was also less (75 and 430 mL, p < 0.001). Median postoperative hospitalization duration was longer in the laparotomy group (2 and 7 days, p = 0.001). After adjusting presurgery risk factors, the PFS and OS were no significant difference in MIS and laparotomy groups.

CONCLUSION

Using real-world data with long-term follow-up, we could confirm excellent PFS and OS in selective patients with clinical stage 1 endometrial carcinoma who received MIS, and the surgical time, hospital day, and blood loss were also less.

Improved Progression-Free Survival Associated with Tumor-Infiltrating Lymphocytes in High-Grade Endometrial Cancer

Tumor-infiltrating lymphocytes (TILs) have emerged as a prognostic marker in endometrial cancer (EC). However, the role of TILs in EC with distinct histology grades and molecular types (such as mismatch repair [MMR] deficiency) has not yet been made clear. We retrospectively included 237 patients with primary EC who underwent a standard staging operation of laparoscopic or laparotomy total hysterectomy and bilateral salpingo-oophorectomy for analyses. An independent pathologist who was blind to the study patients' information reviewed the pathologic slides to assess TILs according to the method introduced by the International Immuno-Oncology Biomarkers Working Group in 2017. The outcomes of interest included both progression-free survival (PFS) and overall survival (OS). The Kaplan-Meier method was used to determine the curves of PFS and OS according to TILs, and also in the relevant subgroups (low-grade vs. high-grade, MMR-proficient vs. MMR-deficient). After a median follow-up duration of 1.82 years, 18 patients had experienced either disease progression or death. Overall, TILs (+) were not associated with PFS or OS. We did observe, however, that TILs (+) were associated with a better PFS (p = 0.045) in patients with high-grade EC, but not in those with low-grade tumors (p = 0.733). The effect of TILs on PFS was not observed in patients with MMR-proficient (p = 0.347) or MMR-deficient (p = 0.168) EC. TILs were associated with a better PFS in patients with high-grade EC. Our results suggest that TILs may be a potential prognostic marker in these patients.

Long-Term Efficacy and Toxicity of Intensity-Modulated Radiotherapy in Bulky Cervical Cancer

Treatment of bulky cervical cancer is associated with both high adverse effects and local recurrence rates with traditional box method radiotherapy. Intensity-modulated radiotherapy (IMRT) has been adopted for the treatment of cervical cancer in order to deliver more precise radiation doses to the target region. We retrospectively enrolled a total of 98 patients with cervical cancer ≥4 cm who completed IMRT and point A-based brachytherapy treatment. The median follow-up time of the cohort was 6.84 years, with the 5-year OS and DFS being 66.33% and 75.12%, respectively. In addition, 7.14% of patients experienced local recurrence, 12.24% had distant recurrence, 6.12% had both local and distant recurrence, and 3.06% had persistent disease. In the univariate analysis, lymph node metastasis, higher creatinine levels, higher initial CA-125 and receiving chemotherapy other than cisplatin were all associated with a worse PFS. A tumor size ≥6 cm was associated with an increased incidence of higher grade of acute diarrhea. Grade 3 late radiation proctitis and cystitis developed in 11.22% and 13.27% of patients, respectively. The local recurrence rates and overall efficiencies were not inferior to other studies involving traditional pelvic external beam radiation therapy with concurrent chemotherapy. The safety and efficacy of IMRT for bulky cervical cancer were acceptable.

Outcomes of “sandwich” chemoradiotherapy compared with chemotherapy alone for the adjuvant treatment of FIGO stage III endometrial cancer

Objective

To analyze and compare outcomes of adjuvant chemoradiotherapy in patients with International Federation of Gynecology and Obstetrics (FIGO) stage III endometrial cancer (EC) patients using the “Sandwich” sequence and chemotherapy (CT) alone.

Methods

From, 2005 to, 2019, we retrospectively reviewed 80 patients with FIGO stage III EC who received treatment at our institute. We analyzed 66 patients who had undergone complete surgical staging followed by adjuvant treatment with sandwich chemoradiotherapy (39 patients) and CT alone (27 patients). The 5-year overall survival (OS), progression-free survival (PFS), and disease-specific survival (DSS) were calculated using the Kaplan–Meier method. Additional prognostic factors were analyzed using Cox proportional hazards regression.

Results

Herein, the analysis was conducted using 66 patients with a median follow-up period of 50 and 85 months in the sandwich and CT-alone arms. Comparing the sandwich sequence and CT-alone groups, the 5-year OS and PFS were 87% vs. 70% (p = 0.097) and 77% vs. 65% (p = 0.209), respectively. The sandwich therapy conferred an improved 5-year DSS (92% vs. 70%, p = 0.041) and a lower local recurrence rate (0% vs. 11%, p = 0.031). In multivariable analyses, grade 3 histology and deep myometrial invasion were independent risk factors for 5-year OS and DSS. The sandwich sequence was a positive predictor for 5-year DSS (hazard ratio [HR] = 0.23, p = 0.029). The sandwich arm demonstrated higher acute hematologic toxicity than the CT-alone arm. CT dose delay/reduction and treatment completion rates were similar in both groups.

Conclusion

For patients with stage III EC, postoperative sandwich chemoradiotherapy appears to offer a superior 5-year DSS and local control with tolerable toxicity when compared with CT alone.

Real-World Efficacy of Bevacizumab in Patients With Recurrent Epithelial Ovarian Cancer

Background

Bevacizumab in combination with chemotherapy prolonged the progression-free survival (PFS) of patients with recurrent epithelial ovarian cancer (EOC) in large-scale randomized controlled trials. However, real-world data for the use of bevacizumab in Asian patients with EOC is lacking. This study investigated the efficacy of adding bevacizumab to chemotherapy and compared it with that of chemotherapy alone in patients with recurrent EOC using real-world data from an Asian population.

Method

We conducted a retrospective cohort study using data from a tertiary medical center in central Taiwan. Patients who had EOC with first relapse between 2011 and 2019 were enrolled. Patients’ medical histories, medication treatment, and relevant information were collected. The outcomes were PFS and overall survival (OS). The Kaplan-Meier plot was used to generate a survival curve for OS and PFS. Cox proportional hazard analysis was used to determine the associations of Bevacizumab treatment with OS and PFS with adjustment of relevant variables. Subgroup analyses were conducted to determine if there was a significant variation in the aforementioned associations.

Results

After a median follow-up of 23 months, 67% of patients in the Bevacizumab group and 81% of patients in the non-Bevacizumab group had disease progression or death. There was no significant between-group difference in OS (p = 0.475). The median duration of PFS was 18.9 and 9.6 months, respectively, favoring those who were treated with Bevacizumab. After multivariate adjustment, treatment with Bevacizumab was associated with a lower risk of disease progression (hazard ratio 0.33, 95% CI 0.13-0.85, p = 0.021). The improvement in PFS was consistent in the subgroups of different histological types, different disease stages at diagnosis, different treatment-free intervals, those undergoing or not undergoing secondary cytoreductive surgery, diverse chemotherapy regimens.

Conclusion

Our findings provided crucial insights into the efficacy of bevacizumab for the treatment of recurrent EOC in the real-world setting.

An Improved Evans Blue Staining Method for Consistent, Accurate Assessment of Plasmodiophora brassicae Resting Spore Viability

Clubroot caused by Plasmodiophora brassicae is an important disease of brassica crops. The use of vital stains to determine the viability of P. brassicae resting spores can provide useful information regarding spore longevity, inoculum potential, or the efficacy of antimicrobial treatments. Evans blue is one example of a vital stain that has been reported to differentially stain viable and nonviable resting spores. Some previously published protocols using Evans blue to stain P. brassicae resting spores have not provided accurate or consistent results. In this study, we modified the Evans blue method by increasing the staining time to 8 h or more and evaluated P. brassicae resting spores after heat treatment at various combinations of temperature and time. Extending staining times significantly increased the numbers of stained resting spores up to 7 h, after which the numbers of stained spores did not change significantly (R² = 96.88; P ≤ 0.001). The accuracy of the modified method to discriminate viable and nonviable spores was evaluated in repeated experiments and by comparing the staining data with those derived from inoculation assays and propidium monoazide quantitative PCR (qPCR). The results demonstrated that the modified Evans blue staining method improved the accuracy and consistency of measurement of P. brassicae resting spore viability. Additionally, it was equivalent to the qPCR method for differentiating viable and nonviable spores (R² = 99.84; P ≤ 0.001) and confirmed in canola infection bioassays.

Do-not-resuscitate status is correlated with the prescribed use of systemic strong opioid analgesics in patients with terminal cancer: an observational study

PURPOSE

The purpose of this study is to determine the possible correlation between the do-not-resuscitate (DNR) status and the prescribed use of systemic strong opioid analgesics (SSOA) among patients with terminal cancer in Taiwan.

METHODS

This retrospective cross-sectional study used data from a single tertiary care medical center. We identified patients with terminal cancer who died after signing a DNR order between 2008 and 2016. Subsequently, we reviewed their clinical characteristics, DNR consent type, survival time after DNR declaration, and SSOA dose.

RESULTS

Of the 4123 patients enrolled for this study, 1380 (33.5%) had received SSOA before DNR and 2742 (66.5%) had received SSOA after DNR (p < 0.001). SSOA doses administered after the DNR order were significantly higher than those administered before the DNR order (median, 78 vs. 60 mg, p < 0.01).

CONCLUSION

Patients' DNR status likely influenced physician decision in prescribing SSOA. However, additional studies are necessary to clarify the factors that influence the decision-making of physicians regarding SSOA prescription.

Early and late do-not-resuscitate (DNR) decisions in patients with terminal COPD: a retrospective study in the last year of life

Purpose

The unpredictable trajectory of COPD can present challenges for patients when faced with a decision regarding a do-not-resuscitate (DNR) directive. The current retrospective analysis was conducted to investigate factors associated with an early DNR decision (prior to last hospital admission) and differences in care patterns between patients who made DNR directives early vs late.

Patients and methods

Electronic health records (EHR) were reviewed from 271 patients with terminal COPD who died in a teaching hospital in Taiwan. Clinical parameters, patterns of DNR decisions, and medical utilization were obtained. Those patients who had a DNR directive earlier than their last (terminal) admission were defined as “Early DNR” (EDNR).

Results

A total of 234 (86.3%) patients died with a DNR directive, however only 30% were EDNR. EDNR was associated with increased age (OR=1.07; 95% CI: 1.02–1.12), increased ER visits (OR=1.22; 95% CI: 1.10–1.37), rapid decline in lung function (OR=3.42; 95% CI: 1.12–10.48), resting heart rate ≥100 (OR=3.02; 95% CI: 1.07–8.51), and right-sided heart failure (OR=2.38; 95% CI: 1.10–5.19). The median time period from a DNR directive to death was 68.5 days in EDNR patients and 5 days in “Late DNR” (LDNR) patients, respectively (P<0.001). EDNR patients died less frequently in the intensive care unit (P<0.001), received less frequent mechanical ventilation (MV; P<0.001), more frequent non-invasive MV (P=0.006), and had a shorter length of hospital stay (P=0.001).

Conclusions

Most patients with terminal COPD had DNR directives, however only 30% of DNR decisions were made prior to their last (terminal) hospital admission. Further research using these predictive factors obtained from EHR systems is warranted in order to better understand the relationship between the timing associated with DNR directive decision making in patients with terminal COPD.

Clinical parameters associated with absence of endocervical/transformation zone component in conventional cervical Papanicolaou smears

OBJECTIVE

To study clinical factors predicting the absence of endocervical/transformation zone (EC/TZ) components of conventional cervical Papanicolaou (Pap) smears.

MATERIALS AND METHODS

The medical charts of patients who received Pap smears between March 2006 and August 2006 in the hospital were reviewed. The results of their Pap smears were retrieved while their demographic and clinical information were obtained from the medical charts. After excluding 378 cases with incomplete demographic data and 1397 cases with a history of pelvic irradiation, pelvic malignancy, and hysterectomy, 5662 cases were enrolled for data analysis. The relationship between clinical parameters and the absence of EC/TZ component was analyzed by Pearson Chi-square tests with Yates continuity correction and binary logistic regression tests.

RESULTS

The incidence of satisfactory but absence of EC/TZ component was 8.7% (491/5662). Pregnancy increased the absence of EC/TZ component [odds ratio (OR}: 2.84, 95% confidence interval (CI): 2.14-3.77, p<0.0001]. Postpartum status and endocervical polyps decreased incidence (OR: 0.61, 95% CI: 0.38-0.98, p = 0.043 and OR: 0.33, 95% CI: 0.25-0.44, p<0.0001, respectively).

CONCLUSIONS

Pregnancy is the only clinical factor associated with increased incidence of absence of EC/TZ cells. For these pregnant women undergoing a Pap smear, a more effective strategy may be needed to get a satisfactory smear with adequate EC/TZ components.

First Report of Fusarium cuneirostrum Causing Root Rot Disease in Dry Bean (Phaseolus vulgaris) in Canada

Root rot is a major disease of dry bean and can cause significant yield reductions due to weakened root systems and poor plant stands. An in-depth study on root rot pathogen identification was conducted in 2011 in three commercial dry bean fields from the major production areas in Manitoba. Ten plants, sampled at each of four random sites within each field, were rated for disease severity. Twenty roots were processed for pathogen isolation and identification in the laboratory. Roots were cut into eight sections (~1 cm) and surface-sterilized in a laminar flow bench. Four root sections were placed on potato dextrose agar plates amended with 0.02% streptomycin sulfate (PDA-Strep) and four root sections were placed on peptone-pentachloronitrobenzene agar amended with 0.1% streptomycin sulfate and 0.012% neomycin sulfate. Afterward, 960 monosporic cultures were obtained representing 320 single spore isolates of potential root rot pathogens per commercial field. Common monosporic cultures from each field were subcultured on PDA-Strep and Spezieller Nährstoffarmer Agar (SNA) media. Based on morphological characteristics, 74 isolates were identified as Fusarium cuneirostrum (1). Colonies grew slowly on PDA-Strep with undulated margins, radial cream-grey mycelia, and conidia pustules with a cream-greyish pigmentation. Sporodochial conidia were falcate, mostly 5-septate, with a wedge shape and slightly protruding basal foot cell (56.3 to 71.8 × 4.6 to 6.2 μm on average). Species identity was confirmed for two isolates by sequencing the translation elongation factor 1 alpha (EF1-α) gene (2), the internal transcribed spacer (ITS) region (4), and the ribosomal intergenic spacer (IGS) (3) (GenBank Accession Nos. KF530848, KF530849, and KF025648 to 51). Sequence homology was compared using BLAST analysis and the FUSARIUM-ID database. The F. cuneirostrum isolates were deposited at the Canadian Collection of Fungal Cultures (DAOM 242540 and 242541). Pathogenicity screenings of two isolates was performed using sterilized seed of navy bean cv. Envoy. Seeds were germinated on moist filter paper for 3 days at 25°C and then inoculated by immersion in a prepared conidial suspension (2.5 × 10⁵ conidia/ml) for 5 min. Seeds of the controls were immersed in sterile water. After inoculation, the germinated seeds were planted in 10-cm diameter pots, filled with sterile soilless mix (Sunshine #3). In the greenhouse, the experiment was arranged as a completely randomized design with three replicates with four germinated seeds per isolate, and was repeated twice. Disease assessment was performed 14 days after inoculation. Infected plants displayed dark brown lesions on the hypocotyl and primary root with a disease severity of 4 scored on a 0 to 5 scale. Fusarium cuneirostrum was re-isolated from roots of symptomatic plants. To our knowledge, this is the first report of F. cuneirostrum causing root rot of dry bean in Canada. It has been previously isolated from mung bean (Vigna radiata) in Ontario (1). References: (1) T. Aoki et al. Mycoscience. 46:162, 2005. (2) D. M. Geiser et al. Eur. J. Plant Pathol. 110:473, 2004. (4) H. Wang et al. J. Clin. Microbiol. 49:1890, 2011. (3) T. J. White et al. Page 315 in: PCR Protocols: A Guide to Methods and Applications. M. A. Innis et al., eds. Academic Press, New York, 1990.

Factors affecting the place of death among hospice home care cancer patients in Taiwan

BACKGROUND

Some patients who receive hospice home care still end up dying in hospital. The significance of the variables possibly affecting the place of death in patients with terminal cancer who received hospice home care was examined.

METHODS

Retrospective study.

RESULTS

Four hundred and thirty-nine patients were enrolled in this study. In all, 60.8% of the patients died at home and 39.2% of the patients died in hospital. Multiple logistic regression analysis revealed that preferred place of death was the prior factor associated with home death, followed by average days of rehospitalization, education level, distance between home and hospital, and age.

CONCLUSIONS

For a better hospice care service, it is essential to inquire patients or their relatives on preferred place of death while concerning the influences of other factors.

Evidence that the biofungicide Serenade (Bacillus subtilis) suppresses clubroot on canola via antibiosis and induced host resistance

This study investigated how the timing of application of the biofungicide Serenade (Bacillus subtilis QST713) or it components (product filtrate and bacterial cell suspension) influenced infection of canola by Plasmodiophora brassicae under controlled conditions. The biofungicide and its components were applied as a soil drench at 5% concentration (vol/vol or equivalent CFU) to a planting mix infested with P. brassicae at seeding or at transplanting 7 or 14 days after seeding (DAS) to target primary and secondary zoospores of P. brassicae. Quantitative polymerase chain reaction (qPCR) was used to assess root colonization by B. subtilis as well as P. brassicae. The biofungicide was consistently more effective than the individual components in reducing infection by P. brassicae. Two applications were more effective than one, with the biofungicide suppressing infection completely and the individual components reducing clubroot severity by 62 to 83%. The biofungicide also reduced genomic DNA of P. brassicae in canola roots by 26 to 99% at 7 and 14 DAS, and the qPCR results were strongly correlated with root hair infection (%) assessed at the same time (r = 0.84 to 0.95). qPCR was also used to quantify the transcript activity of nine host-defense-related genes in inoculated plants treated with Serenade at 14 DAS for potential induced resistance. Genes encoding the jasmonic acid (BnOPR2), ethylene (BnACO), and phenylpropanoid (BnOPCL and BnCCR) pathways were upregulated by 2.2- to 23-fold in plants treated with the biofungicide relative to control plants. This induced defense response was translocated to the foliage (determined based on the inhibition of infection by Leptosphaeria maculans). It is possible that antibiosis and induced resistance are involved in clubroot suppression by Serenade. Activity against the infection from both primary and secondary zoospores of P. brassicae may be required for maximum efficacy against clubroot.

Isolation and Variation in Virulence of Single-Spore Isolates of Plasmodiophora brassicae from Canada

Clubroot of crucifers, caused by Plasmodiophora brassicae, is emerging as an important disease of canola (Brassica napus) in Alberta, Canada. Populations of the pathogen often consist of a mixture of different pathotypes. Therefore, a simple and efficient method to isolate single resting spores of P. brassicae was developed, based on serial dilution of spore suspensions. The virulence of 24 single-spore isolates, representing five populations of the pathogen from Alberta, Ontario, and British Columbia, was characterized on the differentials of Williams and Somé et al. Symptoms were rated 6 weeks after inoculation and Fisher's least significant difference (P < 0.05) was used to differentiate resistant from susceptible host reactions. The pathotype composition of P. brassicae in Canada appeared more diverse when single-spore isolates were examined rather than populations of the pathogen. In Alberta, at least three and possibly four pathotypes were identified among the 14 isolates tested, whereas a maximum of only two pathotypes had been reported previously when populations of the pathogen were examined. Pathotype 3 or P₂, as classified on the differentials of Williams and Somé et al., respectively, was found to be predominant in the province. The occurrence of other pathotypes at lower frequencies suggests that caution should be used in any breeding strategy, because rare pathotypes of P. brassicae may quickly become predominant if susceptible host genotypes are continuously grown.

A Specific and Sensitive Method for the Detection of Colletotrichum lindemuthianum in Dry Bean Tissue

To facilitate early diagnosis and improve control of bean anthracnose, a rapid, specific, and sensitive polymerase chain reaction (PCR)-based method was developed to detect the causal agent, Colletotrichum lindemuthianum, in bean (Phaseolus vulgaris) seed. Based on sequence data of the rDNA region consisting of the 5.8S gene and internal transcribed spacers (ITS) 1 and 2 of four C. lindemuthianum races and 17 Colletotrichum species downloaded from GenBank, five forward primers were designed and evaluated for their specificity. Among them, one forward primer was selected for use in combination with ITS4 to specifically detect C. lindemuthianum. A 461-bp specific band was amplified from the genomic DNA template of 16 representative isolates of C. lindemuthianum, but not from 58 representative isolates of 17 other Colletotrichum species or 10 bean pathogens. Moreover, to enhance the sensitivity of detection, nested PCR was applied, which allowed the detection of as little as 10 fg of C. lindemuthianum genomic DNA and 1% infected seed powder, which was mixed with 99% healthy seed powder. The diagnostic analysis can be completed within 24 h, compared with about 2 weeks required for culturing. Furthermore, this method can be performed and interpreted by personnel with no specialized taxonomic expertise.

First Report of Rhizoctonia solani AG-4 and AG-2-2 on Lupinus angustifolius in Canada

Narrow-leaved lupine (Lupinus angustifolius L.) is grown as a grain legume crop in Australia and Europe where it is used as feedstock in the livestock and aquaculture industries. During July 2003, a stem rot disease was observed in narrow-leaved lupine (cv. Arabella) plants in a research plot at the Crop Diversification Centre North (CDCN), Edmonton, Alberta, Canada. The disease was also found on cv. Rose at the CDCN and cv. Arabella in experimental fields near Devon, Ellerslie, and Westlock, Alberta during the late spring of 2004. Diseased plants showed dark brown-to-black stems with sunken and constricted lesions at the soil level. Young leaves became shrunken and twisted and seedlings collapsed. Rhizoctonia solani was consistently isolated from lesions on taproots and basal stems of diseased plants. Colonies of cream-colored mycelia grew close to the surface of potato dextrose agar (PDA). Most sclerotia formed inside the medium. Agar disks (1 cm in diameter) of isolates LP-11Bb, LP-24C, and LP-25C were attached to the opposite sides of basal stems (180° apart) of 1-month-old lupine seedlings (cv. Arabella). Inoculated plants were incubated for 2 days in black plastic bags under a greenhouse bench at approximately 20°C. All isolates caused brown lesions on the lower stems (extending up to 7 cm above ground level), girdling, and root rot. Plants wilted within 7 to 10 days after inoculation, and aerial mycelia appeared on the basal stems. R. solani was reisolated from the infected crown tissues using PDA to complete Koch's postulates. The isolates were paired with AG tester strains of R. solani. Isolates LP-11Bb and LP-24C were identified as AG-4 while isolate LP-25C was identified as AG-2-2. In another trial, eight isolates of R. solani (unknown AG types) were tested for virulence on L. angustifolius cv. Arabella using the inoculation method described above. All isolates were pathogenic, and disease severity that was based on a 0 to 4 scale ranged from 2.7 to 3.2. The most virulent strain was LP-24C, which caused a 77% loss in fresh weight compared with the noninoculated control plants. R. solani AG-8 is associated with Rhizoctonia disease of lupine in Australia (1) and also causes bare patch disease of wheat. To our knowledge, this is the first report of R. solani on lupine in Canada. This disease could have a significant impact on the commercial production of lupine in Alberta. Reference: (1) M. W. Sweetingham et al. Pages 466-486 in: Advances in Lupin Disease Management in Australia. Proc. Int. Lupin Conf., 8th. G. D. Hill, ed. International Lupin Association, Canterbury, New Zealand, 1999.

Triplet combination of gemcitabine, carboplatin, and paclitaxel in previously treated, relapsed ovarian and peritoneal carcinoma: an experience in Taiwan

OBJECTIVE

The aim of this phase II study was to evaluate the efficacy and toxicity of gemcitabine, carboplatin, and paclitaxel (GCP) combination as salvage therapy in patients with relapsed ovarian or peritoneal cancer who had previously received platinum-based chemotherapy.

PATIENTS AND METHODS

Patients with progressive ovarian or peritoneal carcinoma who had previously received platinum-based chemotherapy were enrolled. Gemcitabine was administered at 800 mg/m(2) as a 30-min intravenous infusion on days 1 and 8; carboplatin (AUC of 5) and paclitaxel (175 mg/m(2)) were administered as 60-min and 3-h intravenous infusions, respectively, on day 1. Treatment cycles were repeated every 3 weeks for a maximum of nine cycles.

RESULTS

Twenty patients (ovarian carcinoma, 19; peritoneal carcinoma, 1) received this triplet regimen as salvage therapy. All the patients had previously received at least one platinum-based regimen for chemotherapy and 17 of them had received platinum plus paclitaxel. The median number of previous regimens was 2 (range, 1-4), and the median platinum-free interval was 9 months (range, 1-18). A total of 130 cycles were administered with a median of six cycles per patient (range, 3-9). The overall response rate was 75%, including 12 complete responses (60%; 95% confidence interval [CI], 36.1-80.9) and three partial responses (15%; 95% CI, 3.2-37.9). The other five patients showed stable disease (25%; 95% CI, 8.7-49.1). The median duration of the progression-free survival was 6.5 months (range, 3-20). Myelosuppression was the main toxicity, with leukopenia being the most prominent (grade 3/4 toxicity in 35% patients), followed by thrombocytopenia in 20% patients. In addition, 35% patients had grade 3 anemia. All the toxicities were manageable and the patients recovered fully. Among non-hematological toxicities, the only notable one was grades 2 and 3 hepatic toxicity seen in two and one patients, respectively, necessitating a decrease in the paclitaxel dose in two patients.

CONCLUSIONS

GCP combination is an effective salvage chemotherapy in patients with heavily pretreated and relapsed ovarian and peritoneal cancer. The significant side effects of myelosuppression and hepatic toxicity were of moderate severity and manageable.

Characterization of the metabolite produced by Mycosphaerella pinodes, the causal agent of mycosphaerella blight on field peas (Pisum sativum L.)

The metabolite produced by Mycosphaerella pinodes, the causal agent of mycosphaerella blight on field peas, was detected by thin layer chromatography (TLC) and was analyzed for its chemical and pathogenic characteristics. One blue dot was detected using 254nm UV light on TLC plate, and a spray of rho-anisaldehyde (110 degrees C, 30 min) also produced a blue dot. The solvent systems used for TLC analysis were ethyl acetate/water/acetone (5/2/5), chloroform/methanol/glacial acetic acid (19/10/2), toluene/ethyl acetate/90% formic acid (6/3/1), diethylether/methanol/water/90% formic acid (95/4/1/1), and bezene/methanol/acetic acid (24/2/1), with R(f) values (min-max) of 0.09-0.18, 0.88-0.95, 0.06-0.15, 0.39-0.47 and 0.05-0.12, respectively. The recovered metabolite from the TLC plate displayed UV absorption peaks at 212, 244, 250, 256 and 261 nm. The proposed formula of the main component of the metabolite was C16H12N3O6. The TLC-purified metabolite induced symptom of discoloration on detached pea leaves.

Stem Smut (Ustilago hypodytes) on Intermediate Wheatgrass in Canada

Intermediate wheatgrass (Thinopyrum intermedium [Host] Barkworth & D.R. Dewey) (syn. Agropyron intermedium [Host] Beauv.) is becoming an important forage grass species in Alberta, Canada. Severe losses in seed yield due to stem smut (Ustilago hypodytes [Schlecht.] Fr.) were noted in a 70-acre field near Warner, AB, in 1999. The crop had been established in 1993 and harvested for seed each year. Smut symptoms (5% incidence) were noted initially in 1997. Incidence, determined by counting the number of symptomatic stems, increased to 10% in 1998 and 50% in 1999. The symptoms usually appeared in the first week of June. Brown sori developed on infected stems, especially between the uppermost node and the leaf below the flag leaf, and gradually became black during the period of seed filling, which is characteristic of stem smut (1). Teliospores were smooth, spherical to oval, light to dark brown, and 4.5 to 5.0 × 5.0 to 6.8 μm in dimension, which is also consistent with previous descriptions of U. hypodytes. Infected stems occasionally flowered, but did not set seed, so seed yield losses were proportional to disease incidence. Plants infected with stem smut were often stunted. Tissues in the smutty stem often became sunken and stems became twisted and thinner than normal due to the propagation of sori in the stem over time. Stem smut has been reported on crested wheatgrass and slender wheatgrass in other parts of Canada (2) and on T. intermedium in the United States (3). This is the first report of stem smut affecting commercial grass seed production in Alberta, Canada. This disease could also have a significant impact on the seed production of intermediate wheatgrass elsewhere. References: (1) G. W. Fischer. 1953. Manual of the North American Smut Fungi. Ronald Press, New York. (2) B. D. Gossen and D. Regnier. Can. Plant Dis. Surv. 71:88-89, 1991. (3) J. F. Karn and J. M. Krupinsky. Phytopathology 73:1152-1155, 1983.

Responses of giant freshwater prawn (Macrobrachium rosenbergii) to challenge by two strains of Aeromonas spp

The virulence of two Aeromonas strains (A. veronii and A. caviae) isolated from the hepatopancreas of apparently healthy giant freshwater prawns (Macrobrachium rosenbergii) was compared using a challenge by injections. For the A. veronii strain, challenge with 3.7 x 10(5) cells/g of body weight led to 100% mortality; for the A. caviae strain, 3.8 x 10(6) cells/g produced 100% mortality. The 50% lethal doses (LD50) were 2.0 x 10(3) cells/g for A. veronii and 51.2 x 10(3) cells/g for A. caviae. Use of different culture media (trypticase soy broth vs prawn muscle extract) did not significantly affect the virulence of A. veronii. Injection of a sublethal dose (1 x 10(3) cells/g) of A. veronii led to a significant decrease in the total hemocyte count (THC) between 4 and 24 h after injection. Saline injections also caused a similar though less decrease in THC. In the first 24 h after injection of A. veronii (1 x 10(3) cells/g), the change in the percentages of granulocytes (both granular cells and semigranular cells) in the hemolymph was significantly different. After a significant initial increase, the percentage of hyaline cells fell by a factor of 4, from 9 to 2%. Phenoloxidase activity increased fourfold immediately after injection and returned to preinjection levels at 24 h.

First Report of Botrytis Blight, Caused by Botrytis cinerea, on Coneflowers

Coneflowers (Echinacea purpurea (L.) Moench and E. pallida (Nutt.) Nutt. var. angustifolia (DC.) Cronq.) are popular medicinal herbs in North America and Europe. In May 1997, a previously undescribed disease was observed in a commercial field of 3-year-old E. pallida var. angustifolia plants in Vernon, British Columbia, Canada. Diseased plants had small to large, brown or black lesions on leaves and stems. Botrytis cinerea Pers.:Fr. (1,2) was consistently isolated from affected tissues. The pathogen appeared to infect leaves along the margins and tips, and occasionally on other parts of the blade as well. Lesions expanded rapidly under cool, humid conditions. Once the pathogen had invaded the midrib or veins, it advanced rapidly to the petiole and stem, which resulted in collapse of the leaf. The pathogen produced profuse conidia and mycelia on the surface of dead and dying leaves, stems, and blossoms, which resulted in a moldy gray appearance. Under dry conditions, the disease developed slowly or even became quiescent. Large lesions often split and formed holes in leaves. The average size of the conidia produced on naturally infected leaves ranged from 5.5 to 10.5 × 6.8 to 18.3 μm (average 8.1 × 13.0 μm), and on potato dextrose agar (1-month-old culture) ranged from 5.5 to 10.0 × 7.5 to 16.3 μm (average 7.4 × 11.3 μm) based on 100 spore measurements, respectively. Microsclerotia were round, spherical or irregular in shape, and ranged from 1.1 to 3.6 × 1.0 to 3.0 mm. Koch's postulates were verified by spraying potted, 3-month-old, narrow-leaved coneflower (E. pallida var. angustifolia) and 2-year-old purple coneflower (E. purpurea) plants with a spore suspension (4 × 10⁵ conidia/ml). Inoculated plants were enclosed in transparent plastic bags for 7 days at 15/22°C (night/day) with a 12-h photoperiod. Typical symptoms were produced 2 to 7 days after inoculation. Some infected leaves quickly twisted and dried after removal of the plastic bags. Botrytis cinerea was reisolated from the affected tissues. This is the first report of Botrytis blight on Echinacea spp. Although B. cinerea does not usually kill coneflower plants, it often heavily infects disc flowers and young shoots. Therefore, Botrytis blight could have a significant impact on the establishment and productivity of this crop in both the field and greenhouse, especially under cool, wet, growing conditions. References: (1) J. R. Coley-Smith et al. 1980. The Biology of Botrytis. Academic Press, New York. (2) D. J. Morgan. Trans. Br. Mycol. Soc. 56:319, 1971.

Molecular identification and relatedness of potato witches'-broom phytoplasma isolates from four potato cultivars

Four isolates of potato witches'-broom phytoplasma, designated as PW1, PW2, PW3 and PW4, were established on four potato cultivars. The identity of each isolate was confirmed by PCR using two universal primer pairs and one specific primer set derived from phytoplasma of 16S rDNA sequences. The four isolate samples formed similar RFLP patterns after digestion of 1.2 kb PCR products with restriction endonucleases AluI, HhaI, RsaI and Sau3A. The direct DNA sequencing with the specific primer pair showed that there are no differences in the base sequences among PW1, PW2, and PW3 phytoplasma isolates and that PW4 is closely related to them. Thus, the four isolates were identified as members of the clover proliferation group.

First Report of Sclerotinia sclerotiorum on Coneflower

Purple coneflower (Echinacea purpurea (L.) Moench; Asteraceae), a perennial herb originating from North America, is used as a garden ornamental and is grown commercially for use in medicinal preparations as an immunostimulant. In October 1996, a previously undescribed stem rot disease was observed in a research plot of 6-month-old echinacea plants at Brooks. Seedlings had been raised in small rockwool cubes (2 × 2 × 5 cm³) in a greenhouse, then transplanted into the field in early June. By late August, dead and dying plants were observed throughout the stand. They had dark brown to black stem lesions above and at the soil level and dead leaves with bleached petiole lesions that extended ca. 15 cm above the axil. Diseased stems and petioles often disintegrated, leaving only fibrous tissues intact. Roots were rotted and black. Superficial white mycelium developed over the basal part of affected stems. Black, oblong to irregular-shaped sclerotia, 5.1 to 17.6 mm in size, formed externally on the crown areas after plant death. Sclerotinia sclerotiorum (Lib.) de Bary (1) was isolated from the diseased plants. Five isolates were selected to fulfill Koch's postulates with 3-month-old echinacea seedlings grown in 12-cm pots of soilless mix. Sclerotia from wilted, field-grown echinacea plants were transferred onto potato dextrose agar medium for 2 days at 20°C. Agar disks were cut with a 1-cm cork borer and two plugs containing sclerotial and mycelial tissues were inserted into the soilless mix 0.5 cm deep and 0.5 cm from the opposite sides of stems of test plants. Inoculated plants were enclosed in transparent plastic bags for 5 days and incubated in a growth chamber at 15/18°C (night/day) with a 12-h photoperiod. One to four lower leaves per plant wilted within 1 week after inoculation and aerial mycelia appeared on the petioles. Infected leaves quickly withered, dried, and dropped off the plant after the bags were removed. Plants often died 3 weeks after inoculation and S. sclerotiorum was reisolated from infected crown tissues. This disease was also found on 3-year-old plants of E. pallida (Nutt.) Nutt. var. angustifolia (DC.) Cronq. in Vernon, British Columbia, Canada, in May 1997. This is the first report of sclerotinia stem rot on Echinacea spp., a disease that could have a significant impact on the longevity and productivity of this crop in the field and greenhouse. Reference: (1) L. H. Purdy. Phytopathology 69:875, 1979.

First Report of Stevia as a Host of Sclerotinia sclerotiorum

Stevia (Stevia rebaudiana Bertoni; Asteraceae), an annual plant originating from Paraguay, contains glucosides of a diterpenoid (2), which is used as a low-caloric sweetener in some South American and southeast Asian countries. The main active ingredient, stevioside, is 100 to 300 times as sweet as sucrose. Stevia has been experimentally grown under field conditions in central and western Canada and has the potential to become a commercially viable alternative crop. In August 1996, a previously undescribed stem rot disease was observed on stevia plants at the Crop Diversification Centre South, Brooks, Alberta. The disease was found in research plots where 4-month-old plants were growing in loam soil. Diseased stems showed dark brown lesions above and at soil level when plant height reached approximately 30 cm. Under dry conditions, mild stem lesions caused plant stunting with lower leaves turning black and curling downward. Wilted leaf symptoms gradually spread upward in affected plants. Partial wilting symptoms appeared when girdling was restricted to branches. The entire plant collapsed when girdling of the crown and roots occurred. Superficial white mycelium developed over the basal part of affected stems under moist conditions, especially after rainy periods. Black, round to oblong sclerotia, 3.5 to 10.1 mm in size, formed externally on the crown areas after plant death. Sclerotinia sclerotiorum (Lib.) de Bary (1) was consistently isolated from the diseased plants. To confirm pathogenicity, 4-week-old stevia seedlings were obtained from shoot cuttings and grown in 12-cm pots of soilless mix. Sclerotia produced on potato dextrose agar were inserted into the mix 0.5 cm deep and 0.5 cm from the stems of test plants. Plants were placed in a growth chamber at 22°C with a 12-h photoperiod and 95% relative humidity. Two weeks after soil infestation, plants wilted and S. sclerotiorum was reisolated from the diseased crown tissues. This is the first report on stevia of sclerotinia stem rot, a disease that could significantly reduce foliar growth and stevioside production in field plantings. References: (1) L. H. Purdy. Phytopathology 69:875, 1979. (2) T. Robinson. 1991. The Organic Constituents of Higher Plants: Their Chemistry and Interrelationships. 6th ed. Cordus Press, North Amherst, MA.

Metobromuron/metolachlor ingestion with late onset methemoglobinemia in a pregnant woman successfully treated with methylene blue

Metobromuron, a substituted urea herbicide, is widely used for control of grasses and broad-leaved weeds in Taiwan. Major systemic toxicity has not been reported following poisoning. A 22-year-old woman at 36 weeks of gestation was admitted to the emergency department three hours after ingestion of a mixture of 25% metobromuron and 25% metolachlor. Though stable initially, she developed central cyanosis 12 hours later. Emergent cesarean section was considered but administration of intravenous methylene blue readily reversed the cyanosis and prevented the operation. Recurrent cyanosis did not develop. Normal vaginal delivery occurred 17 days after the poisoning. Follow-up for four years revealed normal growth of the child. Metobromuron poisoning, like other urea herbicides, may cause methemoglobinemia via its hydrolysis products. Administration of methylene blue is effective treatment and should be considered in the treatment of methemoglobinemia following urea herbicide poisoning.

Termination of pathological pregnancy in second and early third trimesters with extraamniotic instillation of 16-phenoxy-omega-tetranor prostaglandin E2 methylsulfonylamide

OBJECTIVES

To evaluate the efficacy, safety and influence on subsequent fertility of sulprostone, a prostaglandin E2 analog, in terminating pathological pregnancies via the extraamniotic route.

METHODS

Forty pregnant women with intrauterine fetal death or major congenital anomalies were enrolled. Sulprostone was instilled into the extraamniotic space through a silicon Foley catheter. The instillation rate was 0.5-1 microgram/min. Instillation was discontinued when the catheter was expelled or when rupture of the membranes occurred. The duration of instillation and the time interval to completion of abortion was recorded. Information about subsequent fertility was collected by telephone or at outpatient clinic visits.

RESULTS

The mean duration of instillation was 7.0 h and the mean dose of sulprostone was 314.8 micrograms. The mean induction-to-abortion interval (IAI) was 17.0 h. In two of the 40 patients, the cervix was not adequately ripened after 48 h and these pregnancies were ultimately terminated by alternative methods. The success rate of termination in 48 h was 92.5% (37/40). No severe side effects were encountered.

CONCLUSION

To the best of our knowledge, this is the first report in the English literature of administration of sulprostone by extraamniotic instillation for termination of pathological pregnancies. The method is effective and safe and has an insignificant influence on subsequent fertility.

Prenatal diagnosis of placental chorioangioma: contribution of color Doppler ultrasound

A case of placental chorioangioma was diagnosed at 35 weeks' gestation using color Doppler ultrasound. Color flow imaging showed an intraplacental hypoechoic mass fed directly by the anomalous chorionic tumor vessels arising from the insertion of the umbilical cord. Hypervascularization was present in some areas of the tumor. The diagnosis of typical 'angiomatous' type was confirmed by histopathological examination following delivery.

Uptake of low density lipoproteins by rat tissues. Special emphasis on the luteinized ovary

The aim of this study was to determine how luteal cells of the hormone-primed (luteinized) ovary process low density lipoproteins (LDL). Ovary uptake of perfused 125I-LDL was assessed by tissue levels of radioactivity; the distribution of LDL protein in cells was assessed on autoradiograms of the fixed tissue; and the level of stimulation of steroidogenesis, as well as degradation of LDL protein, was assessed on effluent perfusion samples. Human LDL ligand used in these studies was rigorously defined biochemically and physiologically. Homologous (rat) LDL was used as a special ligand control. Other tissue controls included the use of perfused or in vivo-infused luteinized ovaries from animals pretreated to reduce circulating lipoprotein levels, perfused ovaries from a second hormone-primed model, perfused liver from estrogen-treated rats, and isolated and cultured cells from the same ovarian tissues used in the perfusion experiments. The results show that perfused LDL promptly stimulates steroidogenesis. However, the labeled protein moiety of the LDL is not interiorized by the luteal cells, nor is there evidence of LDL protein degradation in the effluent samples. In contrast, internalization of the ligand occurs when luteal cells are incubated with the ligand in vitro. We have observed also that uptake of the 125I-LDL by the ovary can be displaced equally well by excess unlabeled LDL or HDL3. Overall, these experiments suggest that in the intact luteinized ovary, LDL binds to the same sites on the cell surface where HDL "binds," and that LDL cholesterol must be obtained by these steroid hormone-producing cells by a mechanism that does not require internalization of the intact lipoprotein particle.

Effects of antimicrotubule agents on phospholipid metabolism in rat hepatic subcellular membranes

Treatment of animals with antimicrotubule drugs has been shown to cause a perplexing variety of cellular changes which, theoretically, could be the result of changes in endomembrane biosynthesis, composition or flow. In the current study we have focused on this possibility by identifying antimicrotubule drug-induced changes in the phospholipid metabolism of hepatic subcellular membranes. Young adult rats were pretreated with radiolabeled [32 P]orthophosphate for 12 hr, and subsequently given saline, colchicine (2.5 mg/kg body wt) or vinblastine (20 mg/kg body wt) for 4 additional hr. Afterwards, the livers were homogenized, and separate microsomal and Golgi membrane fractions were prepared and subjected to phospholipid extraction and identification using two-dimensional thin-layer chromatography. The results show that colchicine and vinblastine given in vivo caused specific, rapid and in some cases, dramatic changes in phospholipid turnover in different membrane fractions of rat liver. The drugs specifically increased labeling of phosphatidylinositol-4-monophosphate and phosphatidylinositol-4,5-biphosphate and decreased the radioactivity associated with phosphatidylcholine, phosphatidylethanolamine and phosphatidylinositol in all fractions examined. In contrast, the antimicrotubule drugs produced a differential effect on the labeling pattern of sphingomyelin and lysophosphatidylcholine, i.e. they stimulated labeling of these phospholipids in microsomes, produced no changes in heavy Golgi fractions, and markedly increased their labeling in light Golgi fractions. These data suggest that antimicrotubule drugs restrict the incorporation of certain precursor phospholipids into forming membranes but do not affect the subsequent metabolism of these phospholipids. At the same time, the drugs appear to retard the flow of membranes from one cellular compartment to another.

Effect of antimicrotubule agents on terminal glycosyltransferases and other enzymes associated with rat liver subcellular fractions

Previous studies have shown that anti microtubule agents disrupt Golgi complexes in hepatocytes and other cells, causing breakdown or vesiculation of Golgi cisternal membranes. Whether this change in the structure of the Golgi membranes is associated with changes in Golgi membrane function is not known. The present study was initiated to investigate this issue; i.e., to determine whether anti-microtubule agents that cause structural changes in Golgi membranes in vivo would, at the same time, affect characteristic enzyme functions of Golgi membranes. To this end, colchicine was given to young rats in vivo and various hepatic subcellular membranes were subsequently isolated and utilized for enzyme assays. Initially it was shown that colchicine (2.5 mg/kg body wt.) given for 5h significantly decreased the activities of the Golgi membrane associated enzymes galactosyl-, sialyl- and N-acetylglucosaminyl-transferases. More detailed experiments indicated that low doses of colchicine (0.8 mg/kg body wt.), although less effective than higher doses, decreased the activities of the terminal glycosylating enzymes maximally at 5h, with partial and complete recovery at 12 and 24h respectively. Treatment in vivo of rats with vinblastine (20 mg/kg body wt.) for 5h mimicked the action of colchicine. Two microsomal glycosylating enzymes (mannosyl and N acetylglucosaminyl transferases) were unaffected by the treatment with colchicine, as were various hepatic 'marker' enzymes such as 5' nucleotidase, glucose 6 phosphatase and succinate: 2-(p iodophenyl)-3-(p nitrophenyl)-5-phenyltetrazolium reductase (succinate dehydrogenase; EC 1.3.99.1), which were found to be enriched in plasma membrane, endoplasmic-reticulum and mitochondrial-membrane fractions respectively. These results show that anti-microtubule agents specifically suppress the activity of Golgi-associated glycosyltransferases in liver. Although it seems likely that these changes are related to the previously observed structural changes in hepatocyte Golgi complexes after colchicine treatment, to what extent the results are linked to the interaction of colchicine with microtubule protein remains to be clarified.