Bacterial trans‐acyltransferase polyketide synthases (trans‐AT PKSs) are modular megaenzymes that employ unusual catalytic domains to assemble diverse bioactive natural products. One such PKS is ...responsible for the biosynthesis of the oximidine anticancer agents, oxime‐substituted benzolactone enamides that inhibit vacuolar H+‐ATPases. Here, we describe the identification of the oximidine gene cluster in Pseudomonas baetica and the characterization of four novel oximidine variants, including a structurally simpler intermediate that retains potent anticancer activity. Using a combination of in vivo, in vitro and computational approaches, we experimentally elucidate the oximidine biosynthetic pathway and reveal an unprecedented mechanism for O‐methyloxime formation. We show that this process involves a specialized monooxygenase and methyltransferase domain and provide insight into their activity, mechanism and specificity. Our findings expand the catalytic capabilities of trans‐AT PKSs and identify potential strategies for the production of novel oximidine analogues.
The anticancer agent oximidine I and three novel variants were discovered as products of a cryptic trans‐AT PKS/NRPS in Pseudomonas baetica. By manipulating the biosynthetic pathway, a key intermediate was identified that retains potent anticancer properties. A combination of bioinformatics analysis and genetic and biochemical experiments illuminated the oximidine biosynthetic pathway, including a novel mechanism for O‐methyloxime formation.
Bacterial trans‐acyltransferase polyketide synthases (trans‐AT PKSs) are modular megaenzymes that employ unusual catalytic domains to assemble diverse bioactive natural products. One such PKS is ...responsible for the biosynthesis of the oximidine anticancer agents, oxime‐substituted benzolactone enamides that inhibit vacuolar H+‐ATPases. Here, we describe the identification of the oximidine gene cluster in Pseudomonas baetica and the characterization of four novel oximidine variants, including a structurally simpler intermediate that retains potent anticancer activity. Using a combination of in vivo, in vitro and computational approaches, we experimentally elucidate the oximidine biosynthetic pathway and reveal an unprecedented mechanism for O‐methyloxime formation. We show that this process involves a specialized monooxygenase and methyltransferase domain and provide insight into their activity, mechanism and specificity. Our findings expand the catalytic capabilities of trans‐AT PKSs and identify potential strategies for the production of novel oximidine analogues.
The anticancer agent oximidine I and three novel variants were discovered as products of a cryptic trans‐AT PKS/NRPS in Pseudomonas baetica. By manipulating the biosynthetic pathway, a key intermediate was identified that retains potent anticancer properties. A combination of bioinformatics analysis and genetic and biochemical experiments illuminated the oximidine biosynthetic pathway, including a novel mechanism for O‐methyloxime formation.
Abstract
Objective
Multiple endocrine neoplasia type 1 (MEN1) is a hereditary disease characterized by a high risk of developing primary hyperparathyroidism, duodenopancreatic neuroendocrine tumors, ...and pituitary tumors (PITs). It is unclear if having MEN1 leads to psychological distress because of fear of disease occurrence (FDO), thereby potentially affecting quality of life.
Design
A cross-sectional study was performed using the Dutch MEN1 cohort. All patients received the Cancer Worry Scale (a score ≥14 reflects high FDO), the Medical Outcomes Study 36-item Short-Form Health Survey (SF-36), and questions on sociodemographic and medical history.
Results
A total of 227 of 285 (80%) eligible patients with MEN1 completed the questionnaire. The mean (± standard deviation) age was 47 ± 15 years. Overall, patients experienced an FDO of 15.1 ± 4.7, with 58% of patients having a score ≥14. This is higher than reported in previous studies assessing fear of cancer recurrence in different cancer populations (31% to 52%). Adjusted for age and sex, the FDO score was negatively associated with almost all SF-36 subscales. In multivariable analysis, the diagnosis of a PIT, a pancreatic neuroendocrine tumor, and not being employed were associated with FDO (P < 0.05). Patients had higher FDO scores for their family members than for themselves.
Conclusion
The majority of patients with MEN1 have FDO for themselves and even more for their relatives. This psychological distress is associated with a lower health-related quality of life. Therefore, in the medical care for MEN1, emphasis should also be placed on FDO and quality of life.
The majority of patients with MEN1 have high fear of disease occurrence. This psychological distress is associated with a lower health-related quality of life.
Purpose
To assess the impact of an
18
FFDG-PET/CT-driven diagnostic workup to rule out malignancy, avoid futile diagnostic surgeries, and improve patient outcomes in thyroid nodules with ...indeterminate cytology.
Methods
In this double-blinded, randomised controlled multicentre trial, 132 adult euthyroid patients with scheduled diagnostic surgery for a Bethesda III or IV thyroid nodule underwent
18
FFDG-PET/CT and were randomised to an
18
FFDG-PET/CT-driven or diagnostic surgery group. In the
18
FFDG-PET/CT-driven group, management was based on the
18
FFDG-PET/CT result: when the index nodule was visually
18
FFDG-positive, diagnostic surgery was advised; when
18
FFDG-negative, active surveillance was recommended. The nodule was presumed benign when it remained unchanged on ultrasound surveillance. In the diagnostic surgery group, all patients were advised to proceed to the scheduled surgery, according to current guidelines. The primary outcome was the fraction of unbeneficial patient management in one year, i.e., diagnostic surgery for benign nodules and active surveillance for malignant/borderline nodules. Intention-to-treat analysis was performed. Subgroup analyses were performed for non-Hürthle cell and Hürthle cell nodules.
Results
Patient management was unbeneficial in 42% (38/91 95% confidence interval CI, 32–53%) of patients in the
18
FFDG-PET/CT-driven group, as compared to 83% (34/41 95% CI, 68–93%) in the diagnostic surgery group (
p
< 0.001).
18
FFDG-PET/CT-driven management avoided 40% (25/63 95% CI, 28–53%) diagnostic surgeries for benign nodules: 48% (23/48 95% CI, 33–63%) in non-Hürthle cell and 13% (2/15 95% CI, 2–40%) in Hürthle cell nodules (
p
= 0.02). No malignant or borderline tumours were observed in patients under surveillance. Sensitivity, specificity, negative and positive predictive value, and benign call rate (95% CI) of
18
FFDG-PET/CT were 94.1% (80.3–99.3%), 39.8% (30.0–50.2%), 95.1% (83.5–99.4%), 35.2% (25.4–45.9%), and 31.1% (23.3–39.7%), respectively.
Conclusion
An
18
FFDG-PET/CT-driven diagnostic workup of indeterminate thyroid nodules leads to practice changing management, accurately and oncologically safely reducing futile surgeries by 40%. For optimal therapeutic yield, application should be limited to non-Hürthle cell nodules.
Trial registration number
This trial is registered with ClinicalTrials.gov: NCT02208544 (5 August 2014),
https://clinicaltrials.gov/ct2/show/NCT02208544
.
Objective This study assessed the health-related quality of life (HRQoL) in patients undergoing 2-18Ffluoro-2-deoxy-D-glucose (FDG)-PET/CT for an indeterminate (Bethesda III/IV) thyroid nodule. ...FDG-PET/CT accurately rules out malignancy and prevents 40% of futile diagnostic surgeries in these nodules. Design Secondary analyses of HRQoL data from a randomised controlled multicentre trial (NCT02208544) in 126 patients from 15 hospitals in the Netherlands were done. Methods Longitudinal HRQoL assessment was performed using the EuroQol 5-dimension 5-level (EQ-5D-5L), the RAND 36-item Health Survey v2.0 (RAND-36), and the Thyroid Patient-Reported Outcome (ThyPRO) questionnaire on baseline, 3, 6, and 12 months, relative to the date of the FDG-PET/CT scan. Results Patients who were randomised to active surveillance following an FDG-negative nodule instead of diagnostic surgery reported stable HRQoL scores throughout the year. Univariate analysis indicated better HRQoL for patients undergoing surveillance than surgical patients with benign histopathology on multiple physical and psychosocial domains. Univariate within-group analysis suggested both temporary and continued HRQoL deteriorations in patients with benign histopathology over time. Multivariate within-group analysis demonstrated no significant longitudinal HRQoL changes in patients undergoing active surveillance. In contrast, in patients with benign histopathology, worse HRQoL was observed with regard to ThyPRO cognitive impairment (P = 0.01) and cosmetic complaints (P = 0.02), whereas goitre symptoms (P < 0.001) and anxiety (P = 0.04) improved over time. In patients with malignant histopathology, anxiety also decreased (P = 0.05). Conclusions The reassurance of a negative FDG-PET/CT resulted in sustained HRQoL throughout the first year of active surveillance. Diagnostic surgery for a nodule with benign histopathology resulted in more cognitive impairment and physical problems including cosmetic complaints, but improved goitre symptoms and anxiety. Anxiety was also reduced in patients with malignant histopathology.
Acute pancreatitis is a severe disease with unpredictable course and outcomes. It is especially hard to identify early those patients who will have a fulminant course. In a prospective observational ...study, we tested the hypothesis that the CT Severity Index (CTSI), established within 48hours after admission, is prognostic for morbidity and mortality and can predict the necessity for admission to an ICU.
From January 1994 to October 2002, all patients with the diagnosis of first time acute pancreatitis underwent spiral CT with intravenous contrast within 48hours of admission. The extent of inflammation and necrosis was assessed to define the CTSI. Patients were initially managed in an ICU in a standardized fashion. Complications and mortality were registered in a systematic manner.
Seventy-nine patients were admitted with acute pancreatitis. The overall complication rate was 57%; mortality was 9%. In patients with a CTSI of 0 to 3, these rates were 42% and 2%, respectively; in those with CTSI of 4 to 6, 81% and 19%, respectively; and in those with CTSI of 7 to 10, 100% and 33%, respectively. Outcomes of subsequent CT scans did not alter the initial prognosis. Early CTSI correlated well with the incidence of complications, sepsis, mortality, and necessity for ICU admission.
Acute pancreatitis is associated with marked morbidity and mortality. Initial admission to an ICU and standardized conservative treatment are justified for all patients. Early establishment of the CTSI is an excellent prognostic tool for complications and mortality. Patients with a CTSI of 0 to 3 can safely be discharged from the ICU.
Background
Rapid genetic counseling and testing (RGCT) in newly diagnosed high‐risk breast cancer (BC) patients may influence surgical treatment decisions. To successfully integrate RGCT in practice, ...knowledge of professionals’, and patients’ attitudes toward RGCT is essential.
Methods
Between 2008 and 2010, we performed a randomized clinical trial evaluating the impact of RGCT. Attitudes toward and experience with RGCT were assessed in 265 patients (at diagnosis, 6‐ and 12‐month follow‐up) and 29 medical professionals (before and after the recruitment period).
Results
At 6‐month follow‐up, more patients who had been offered RGCT felt they had been actively involved in treatment decision‐making than patients who had been offered usual care (67% vs 48%, P = 0.06). Patients who received DNA‐test results before primary surgery reported more often that RGCT influenced treatment decisions than those who received results afterwards (P < 0.01). Eighty‐seven percent felt that genetic counseling and testing (GCT) should preferably take place between diagnosis and surgery. Most professionals (72%) agreed that RGCT should be routinely offered to eligible patients. Most patients (74%) and professionals (85%) considered surgeons the most appropriate source for referral.
Conclusions
RGCT is viewed as helpful for newly diagnosed high‐risk BC patients in choosing their primary surgery and should be offered routinely by surgeons.
Female breast cancer patients carrying a BRCA1/2 mutation have an increased risk of second primary breast cancer. Rapid genetic counseling and testing (RGCT) before surgery may influence choice of ...primary surgical treatment. In this article, we report on the psychosocial impact of RGCT.
Newly diagnosed breast cancer patients at risk for carrying a BRCA1/2 mutation were randomized to an intervention group (offer of RGCT) or a usual care control group (ratio 2:1). Psychosocial impact and quality of life were assessed with the Impact of Events Scale, Hospital Anxiety and Depression Scale, Cancer Worry Scale, and the EORTC QLQ-C30 and QLQ-BR23. Assessments took place at study entry and at 6- and 12-month follow-up visits.
Between 2008 and 2010, 265 patients were recruited into the study. Completeness of follow-up data was more than 90%. Of the 178 women in the intervention group, 177 had genetic counseling, of whom 71 (40%) had rapid DNA testing and 59 (33%) received test results before surgery. Intention-to-treat and per-protocol analyses showed no statistically significant differences between groups over time in any of the psychosocial outcomes.
In this study, RGCT in newly diagnosed breast cancer patients did not have any measurable adverse psychosocial effects.
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