A comprehensive survey on the occurrence of mycotoxins in maize dried distillers' grain and solubles sourced worldwide

As cereal and protein sources suffer a price increase worldwide, the use of alternative ingredients in feeds has become increasingly appealing to the animal industry. Dried distillers' grain and solubles (DDGS) have been one of the ingredients which demand has dramatically increased over the last few years. In fact, the supply of maize DDGS is expected to increase to about 38.6 mmt by 2019-2020. The presence of mycotoxins in these by-products has been a matter of concern raised by their ubiquitous use. A rule of thumb typically used in the field is that the concentration of mycotoxins in the final by-product is about three times higher than that of the original raw material, which may be scientifically backed up by the fact that the remaining portions within the by-product are those which had a higher concentration of mycotoxins (outer portions of the grain). This paper is the outcome of a five-year study during which a total of 409 maize DDGS samples sourced worldwide were analysed for the mycotoxins of major importance which cause the great negative impacts in animal performance and health: aflatoxins (a sum of aflatoxin B1, B2, G1, G2), zearalenone, deoxynivalenol, a sum fumonisins B1 and B2 and ochratoxin A. From the total of samples tested, only 2% of the analysed DDGS showed contamination levels below the limit of detection (negative samples). 6% of samples had the presence of 1 mycotoxin only and the majority (92% of the samples) was contaminated with 2 or more mycotoxins.

Propofol sedation in patients undergoing colonoscopy in Jamaica

BACKGROUND

Propofol sedation is increasingly used for colonoscopy and may be associated with increased satisfaction and efficiency in diagnostic and therapeutic endoscopy. However propofol has a relatively narrow therapeutic window as it frequently produces deep sedation, and can precipitate respiratory depression.

AIM

To determine the efficacy, safety and patient satisfaction with propofol sedation in patients undergoing colonoscopy at the University Hospital of the West Indies (UHWI).

METHODS

Patients undergoing outpatient colonoscopy at the UHWI who were sedated with propofol were studied. Boluses of 10 - 20 mg of propofol at intervals of 2 - 5 minutes, as needed for adequate sedation, were administered after initial induction. Continuous monitoring of the pulse rate, and oxygen saturation were performed and the blood pressure checked every 2 - 5 minutes. All patients received supplemental oxygen (4 L/min). The following observations were recorded: the endoscopist recorded the ease of the procedure, the anaesthetist recorded the comfort of the patient throughout the procedure and at the time of discharge, and the patient stated the degree of satisfaction with the procedure. Any unusual events were recorded.

RESULTS

Sixty consecutive patients sedated with propofol were studied. There were 28 (46.7%) males, with a mean age of 58.3 years and 32 (53.3%) females, with mean age of 59.5 years. Most were normal healthy patients (56.6%). Comorbid illnesses were present in 43.4%, with hypertension being most common (23.3%). All patients were classified as ASA class 1 and 2. The average dose of propofol used was 180 mg (range 50 - 355 mg). The mean duration of colonoscopy was 19.5 minutes. The mean recovery period (able to stand) was 29.6 minutes. There were no documented cases of significant hypotension, bradycardia, or hypoxaemia during the procedure. Transient apnoeic episodes during the initial stages of sedation occurred in 12 (20%) patients. The majority of patients (91.7%) rated the experience as being extremely good or excellent. The majority could not recall the actual colonoscopy and there were minimal subjective reports of nausea or discomfort during the procedure.

CONCLUSIONS

Propofol sedation was associated with quick recovery and excellent satisfaction by patients and is a suitable alternative for sedation for colonoscopy in Jamaica.

Cooperative interactions of PTEN deficiency and RAS activation in melanoma metastasis

Mitogen-activated protein kinase (MAPK) and AKT pathways are frequently co-activated in melanoma through overexpression of receptor tyrosine kinases, mutations in their signaling surrogates, such as RAS and BRAF, or loss of negative regulators such as PTEN. As RAS can be a positive upstream regulator of PI3-K, it has been proposed that the loss of PTEN and the activation of RAS are redundant events in melanoma pathogenesis. Here, in genetically engineered mouse models of cutaneous melanomas, we sought to better understand the genetic interactions between HRAS activation and PTEN inactivation in melanoma genesis and progression in vivo. We showed that HRAS activation cooperates with Pten+/- and Ink4a/Arf-/- to increase melanoma penetrance and promote metastasis. Correspondingly, gain- and loss-of-function studies established that Pten loss increases invasion and migration of melanoma cells and non-transformed melanocytes, and such biological activity correlates with a shift to phosphorylation of AKT2 isoform and E-cadherin down-regulation. Thus, Pten inactivation can drive the genesis and promote the metastatic progression of RAS activated Ink4a/Arf deficient melanomas.

Pten and p53 converge on c-Myc to control differentiation, self-renewal, and transformation of normal and neoplastic stem cells in glioblastoma

Glioblastoma (GBM) is a highly lethal primary brain cancer with hallmark features of diffuse invasion, intense apoptosis resistance and florid necrosis, robust angiogenesis, and an immature profile with developmental plasticity. In the course of assessing the developmental consequences of central nervous system (CNS)-specific deletion of p53 and Pten, we observed a penetrant acute-onset malignant glioma phenotype with striking clinical, pathological, and molecular resemblance to primary GBM in humans. This primary, as opposed to secondary, GBM presentation in the mouse prompted genetic analysis of human primary GBM samples that revealed combined p53 and Pten mutations as the most common tumor suppressor defects in primary GBM. On the mechanistic level, the "multiforme" histopathological presentation and immature differentiation marker profile of the murine tumors motivated transcriptomic promoter-binding element and functional studies of neural stem cells (NSCs), which revealed that dual, but not singular, inactivation of p53 and Pten promotes cellular c-Myc activation. This increased c-Myc activity is associated not only with impaired differentiation, enhanced self-renewal capacity of NSCs, and tumor-initiating cells (TICs), but also with maintenance of TIC tumorigenic potential. Together, these murine studies have provided a highly faithful model of primary GBM, revealed a common tumor suppressor mutational pattern in human disease, and established c-Myc as a key component of p53 and Pten cooperative actions in the regulation of normal and malignant stem/progenitor cell differentiation, self-renewal, and tumorigenic potential.

RTOG 0315: A randomized, double-blind, placebo-controlled phase III study to determine the efficacy of octreotide acetate in preventing or reducing the severity of chemoradiation-induced diarrhea in patients with anal or rectal cancer

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Background: Diarrhea is a common side effect of chemoradiation for pelvic malignancies. Octreotide acetate has been shown to control grade 3–4 chemotherapy-induced diarrhea in >90% of patients. The primary objective of this randomized placebo-controlled phase III study was to determine the efficacy of long acting octreotide acetate in preventing the onset of grade 2–4 diarrhea. Secondary objectives were to assess the impact of diarrhea on chemoradiation delivery and medical resource utilization. Methods: Eligible patients (pts) with primary anal or rectal cancer, and scheduled to receive concurrent chemoradiation to a minimum dose of 45 Gy using pelvic field sizes greater than 10x10cm, were enrolled. Pts with history of pelvic radiotherapy, chronic bowel disease, diarrhea of grade ≥2, or colostomy were excluded from the study. Pts were stratified by RT dose (<50 Gy and ≥50 Gy), chemotherapy (bolus and continuous) and gender. Pts were randomized to receive two 30 mg intramuscular injections of octreotide acetate (Sandostatin LAR® Depot) or placebo. Injections were given between day -7 and day -4 and on day 22 (± 3 days) of RT. The primary endpoint was incidence of grade 2, 3, or 4 diarrhea (CTCAE v3.0). Assuming a 45% placebo incidence rate, a one-sided chi-square test (alpha 0.05) would require 226 pts to detect a 42% reduction in incidence due to octreotide acetate. Results: The study accrued 233 pts (215 analyzable), 106 pts in the placebo arm and 109 pts in the octreotide acetate arm. The majority of pts (80%) on each arm had rectal cancer. There was no statistically significant difference in incidence of grade 2+ diarrhea (p=0.21) with 52 (49%) and 48 (44%) in the placebo and octreotide acetate treatment arms, respectively. There was also no statistically significant difference between the treatment arms in chemoradiation delivery or medical resource utilization. Conclusions: Prophylactic use of octreotide acetate was not shown to significantly reduce the incidence of mild, moderate or severe diarrhea.

No significant financial relationships to disclose.

Common and contrasting genomic profiles among the major human lung cancer subtypes

Lung cancer is the leading cause of cancer mortality worldwide. With the recent success of molecularly targeted therapies in this disease, a detailed knowledge of the spectrum of genetic lesions in lung cancer represents a critical step in the development of additional effective agents. An integrated high-resolution survey of regional amplifications and deletions and gene expression profiling of non-small-cell lung cancers (NSCLC) identified 93 focal high-confidence copy number alterations (CNAs), with 21 spanning less than 0.5 Mb with a median of five genes. Most CNAs were novel and included high-amplitude amplification and homozygous deletion events. Pathogenic relevance of these genomic alterations was further reinforced by their recurrence and overlap with focal alterations of other tumor types. Additionally, the comparison of the genomic profiles of the two major subtypes of NSCLC, adenocarcinoma (AC) and squamous cell carcinoma (SCC), showed an almost complete overlap with the exception of one amplified region on chromosome 3, specific for SCC. Among the few genes overexpressed within this amplicon was p63, a known regulator of squamous cell differentiation. These findings suggest that the AC and SCC subtypes may arise from a common cell of origin and they are driven to their distinct phenotypic end points by altered expression of a limited number of key genes such as p63.

Gamma Knife stereotactic radiosurgery in the treatment of brain metastases from breast cancer

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Background: Outcomes of gamma knife stereotactic radiosurgery (GK-SRS) for patients with brain metastases specifically from breast cancer have not been well-defined. This study was undertaken to report the long-term experience with GK-SRS in this subset of patients. Methods: From 1995 to 2005, 75 patients with 162 brain lesions were treated with GK-SRS at the University of Maryland Medical Center. Complete follow-up data were available in 65 patients. Additional whole brain radiation therapy (WBRT) was administered to 53 (81.5%) patients. The median WBRT dose was 36.75 Gy (30.0–45.0 Gy). The median number of lesions treated with GK-SRS was 2 (1–8 lesions). The median follow-up, age, and KPS were 7.2 months (0.4–75.7 months), 53.5 years (23–81 years), and 90 (40–100), respectively. The factors included in the univariate and multivariate analyses for overall survival (OS) and progression free survival (PFS) were age, Karnofsky Performance Status (KPS), tumor histology, estrogen receptor status, Her-2-neu status, number of intracranial lesions, and presence of systemic disease. Results: Median PFS and OS from GK-SRS were 5.3 months (0.4–33.2 months) and 8.1 months (0.4–75.7 months), respectively. The 6, 12, and 24 month actuarial PFS were 47.8%, 24.9%, and 9.6% respectively. The 6, 12, and 24 month actuarial OS were 60.7%, 39.1%, and 18.1% respectively. The tumor local control after WBRT and GK-SRS was 87.7%. Radiation necrosis was a complication in 10.8% of patients. Forty-seven (72.3%) patients had neurological symptoms prior to gamma knife treatment. Seven (14.9%) and 9 (19.1%) of these patients experienced symptom resolution and significant symptomatic improvement, respectively. Multivariate and univariate analysis did not reveal any of the prognostic factors in question to be significantly associated with OS nor PFS. Conclusions: This relatively large cohort of patients experienced poor survival outcomes despite aggressive therapy with WBRT and GK-SRS. However, GK-SRS can provide significant symptomatic relief, with acceptable complication rates. More research is required to improve the survival of breast cancer patients with intracranial metastases.

No significant financial relationships to disclose.