First report of Agrobacterium tumefaciens causing crown gall disease of roselle (Hibiscus sabdariffa L.) in Taiwan.

Roselle (Hibiscus sabdariffa L.) plants, whose calyces are used for production of beverages or jams, are mainly cultivated in Taitung County of eastern Taiwan. Since 2016, large crown galls were observed on the roselle plants in the commercial plantations at Taimali and Jinfong Townships of Taitung County. A follow-up survey in July and August of 2017 revealed spreading of this disease to the neighboring areas including Beinan and Dawu Townships. Disease incidence was estimated to be 0.6-10%. Galls of varying sizes (2-15 cm in diameter) were usually found on the roots and crowns of the roselle plants, starting with small swellings at the infection sites. Galls were light-colored, and smooth and tender in texture at the early stage, but later turned dark-colored, and appeared rough and woody. In some cases, adventitious roots extruding from the larger crown galls could be seen. Isolation of the causal agent was performed by quadrantally streaking bacterial suspension made from surface-sterilized, macerated galls on trypticase soy agar (TSA). After incubating at 28°C for 5 days, single colonies were transferred onto new TSA plates for further cultivation at 28°C. Finally, circular, convex, viscous and milky white colonies with smooth surface similar to colony morphology of Agrobacterium tumefaciens C58 were obtained for further identification. First, all six candidate isolates (TZ-1, TL1-2, TL2-1, TD1-1, TD1-24 and TD2-1) were identified as Agrobacterium spp. using the partial sequences of the 16S rRNA gene (accession numbers MW205820 to MW205825 in the GenBank database). The selected isolates also showed some biochemical and physiological characteristics similar to A. tumefaciens, including oxidase positive, growth at 35°C and in 2% NaCl, and alkalinity from litmus milk. Moreover, they were tested negative for utilization of citrate and acid production on potato dextrose agar (PDA) supplemented with calcium carbonate. Under a transmission electron microscope, the bacterium was rod-shaped and possessed peritrichous flagella. By means of multiplex PCR using primers designed for differentiation of Agrobacterium rubi, Agrobacterium vitis and Agrobacterium biovars 1 and 2, a 184 bp product was detected in all six isolates, indicating that they all belong to Agrobacterium biovar 1. Furthermore, the recA allele of each isolate was PCR amplified using primers F2898/F2899, and recA sequence analysis assigned all six isolates to A. tumefaciens genomospecies G7 (GenBank accession numbers MZ570905-MZ570910). Pathogenicity assay was carried out by inoculating the stems of 2-week-old roselle seedlings through wounds made with a sterile needle with bacteria on it. The inoculated seedlings were kept in plastic bags to maintain high humidity. Symptoms similar to those observed in the field developed at the inoculation sites after 7 days, and Koch's postulates were fulfilled when the bacteria re-isolated from the galls were also identified as A. tumefaciens genomospecies G7 using recA gene sequence analysis. To our knowledge, this is the first report of crown gall disease caused by A. tumefaciens on Hibiscus sabdariffa in Taiwan. This disease may potentially damage the roselle industry if no action is taken to stop its spreading. Identification of the causal agent of roselle crown gall disease could help us further investigate its ecology and develop integrated pest management strategies for prevention of this disease in the future.

Myocardial injury was associated with neurological sequelae of acute carbon monoxide poisoning in Taiwan.

BACKGROUND: Carbon monoxide (CO) poisoning has recently become a serious health problem in some Asian countries, including Taiwan. The aims of this study are to evaluate the changing trend of CO poisoning and to demonstrate the association between myocardial injury and neurological sequelae of CO poisoning in Taiwan between 1990 and 2011. METHODS: This retrospective cohort study included all eligible patients with acute CO poisoning reported to the Taiwan National Poison Control Center during the study period. The changing trend of CO poisoning and its impacts on the primary outcomes, i.e., persistent neurological sequelae (PNS) and delayed neurological sequelae (DNS), were then assessed. RESULTS: 786 CO poisoned cases were reported. Among them, 467 cases were intentional. Intentional CO exposure started to become the major cause of CO poisoning in Taiwan in 2002. Increase in the number of intentional CO poisoning significantly correlated with the increase in the overall number of CO poisoning (r = 0.972, p < 0.001). Patients who took tranquilizer (OR = 3.89; 95% CI:1.94-7.77), had myocardial injury (OR = 1.70; 95% CI:1.03-2.82), had been stayed in intensive care unit (OR = 2.03; 95% CI:1.13-3.62), presented with GCS less than 9 (OR = 4.05; 95% CI:2.32-7.08) and had abnormal brain image (OR = 14.46; 95% CI:5.83-35.83) had a higher risk of PNS. Moreover, patients who were older age (OR = 1.04; 95% CI:1.02-1.07), had psychiatric disorder history (OR = 2.82; 95% CI:1.35-5.89), had myocardial injury (OR = 1.33; 95% CI:1.16-1.53), and presented with GCS less than 9 (OR = 3.23; 95% CI:1.65-6.34) had a higher risk of DNS. CONCLUSION: The pattern of CO poisoning had changed markedly during the study period, with a significant increase in both the numbers of intentional and overall CO poisoning. Moreover, intentional CO poisoning was associated with a higher risk of neurological sequelae, which was mediated by various indicators of poisoning severity such as myocardial injury and GCS less than 9.

The role of adjuvant chemotherapy in stage II colorectal cancer patients.

PURPOSE: Adjuvant chemotherapy use in stage II colorectal cancer (CRC) is debated. We evaluated the prognostic significance of clinicopathological features recommended by most guidelines for identifying high-risk stage II CRC and adjuvant chemotherapeutic response. METHODS: We enrolled 1,039 stage II CRC patients who underwent curative surgery at Taipei Veterans General Hospital from January 2005 to December 2010. Seventy-seven patients who received radiotherapy were excluded. The endpoint was disease-free survival. RESULTS: Of 962 patients, 37 had stage T4 tumors; 50, lymphovascular invasion; 39, poor differentiation; 249, preoperative carcinoembryonic antigen (CEA) levels >5 ng/mL; and 53 underwent emergent operations. One hundred ninety-four patients received 5-fluorouracil-based adjuvant chemotherapy. During a median follow-up period of 60.2 months, recurrence developed in 110 patients (11.4 %). The 5-year disease-free survival (DFS) was 87.6 %. In multivariate analysis, preoperative CEA >5 ng/ml (p = 0.001), emergent operation for obstruction/perforation (p = 0.008), lymphovascular invasion (p = 0.014), and T4 disease (p = 0.030) were significantly associated with poor DFS. High-risk stage II patients (n = 484) benefited from adjuvant chemotherapy (5-year DFS with and without adjuvant chemotherapy, 87.3 vs. 78.9 %; p = 0.028). CONCLUSIONS: Adjuvant chemotherapy improved DFS in high-risk stage II CRC patients, but not in low-risk patients.

Assessment of the value of carcinoembryonic antigen reduction ratio as a prognosis factor in rectal cancer.

BACKGROUND: Carcinoembryonic antigen (CEA) is the most widely used tumor marker for colorectal cancer. This study aimed to investigate the role of CEA reduction ratio after preoperative chemoradiotherapy (CRT). METHODS: We enrolled 284 patients who underwent preoperative CRT followed by radical surgical resection. Patients were divided into 3 groups: serum CEA levels before CRT (pre-CRT CEA) less than 5 ng/mL (group 1); pre-CRT CEA of 5 ng/mL or more with CEA reduction ratio of 50% or more (group 2); and pre-CRT CEA of 5 ng/mL or more with CEA reduction ratio less than 50% (group 3). RESULTS: The 5-year disease-free survival (DFS) rate was not different between groups 1 (71.8%) and 2 (69.4%) but was significantly lower in group 3 (49.5%). CEA group, lymph node status after CRT (ypN) stage, and histologic type were independent prognostic factors for DFS on multivariate analysis. CONCLUSIONS: CEA reduction ratio might be an independent prognostic factor for DFS in rectal cancer patients treated with preoperative CRT and radical surgery.

Concurrent chemoradiotherapy followed by metastasectomy converts to survival benefit in stage IV rectum cancer.

BACKGROUND: To investigate the impact of concurrent chemoradiotherapy (CCRT) on stage IV rectum cancer. METHODS: Between 2000 and 2011, 297 consecutive patients diagnosed with stage IV rectum cancer (synchronous metastasis) were enrolled. Cox proportional hazard analyses were used for prognostic factors determination, and the Kaplan-Meier method was used for survival analyses. Propensity scores with the one-to-one nearest-neighbor matching model were used to select matched patients for validation studies. RESULTS: In total, 63 patients received CCRT and 234 did not. The patients in the CCRT group were younger, had more low-lying lesions, and had more T4 lesions, lung metastases, metastasectomies, and oxaliplatin-based upfront chemotherapy. Before propensity-score matching, a younger age (HR = 0.662, P = 0.016), lower carcinoembryonic antigen (CEA) level (≤20 ng/ml) (HR = 0.531, P = 0.001), no metastasectomy (HR = 3.214, P < 0.001), and no CCRT (HR = 1.844, P = 0.019) were independent prognostic factors after controlling for other confounding factors. After matching, only CEA and metastasectomy, but not CCRT, were independent prognostic factors. The survival benefit of CCRT was restricted to patients who undergo subsequent metastasectomy. CONCLUSIONS: Upfront CCRT only provided a survival benefit in patients with stage IV rectum cancer who undergo subsequent metastasectomy.

Aconitine intoxication mimicking acute myocardial infarction.

INTRODUCTION: Cardiotoxicity in acute aconitine intoxication is well known; however, elevation of troponin I level and abnormal scintigraphy findings had not previously been reported. CASE REPORT: A 60-year-old man developed chest tightness, syncope and convulsion after ingesting processed Aconitum carmichaeli (Chuanwu) extract for treatment of headache. Electrocardiogram showed first degree atrioventricular (AV) block. Troponin I level was elevated at 14.8 ng/mL 13 hours post-ingestion. Creatine kinase was also increased to 414 U/L. However, echocardiography did not show any abnormal cardiac wall motion. Tc-99m-PYP scintigraphy revealed diffusely increased uptake in the myocardium, suggesting the presence of myocardial necrosis or myocarditis. DISCUSSION: Aconitine poisoning can mimic acute myocardial infarction with chest tightness and elevated cardiac enzymes. Increased cardiac markers and myocardial insult seen in this patient were likely to be related to the toxicity of aconitine. Care should be taken in making the diagnosis in such instances. Management is primarily supportive.

Acute severe chromium poisoning after dermal exposure to hexavalent chromium.

Severe acute chromium poisoning related to dermal involvement has rarely been reported in the literature. We report a case of acute severe chromium poisoning through skin exposure as a result of a chemical burn of 15% of the body surface area and multiple organ failure after short-term exposure. Medical interventions, including mechanical ventilation, continuous venovenous hemofiltration, and plasmapheresis were performed. In addition, a chelating agent, dimercaptopropane sulfonic acid, was infused intravenously, combined with intravenous N-acetylcysteine and ascorbic acid as adjuvant therapy. The patient was discharged on day 33 without long-term sequelae. The consequence of transdermal exposure of hexavalent chromium should not be overlooked.