Setting up regional diagnostic reference levels for pediatric interventional cardiology in Latin America and the Caribbean countries: preliminary results and identified challenges

The goal of the present study was to propose a set of preliminary regional diagnostic reference levels (DRLs) for pediatric interventional cardiology (IC) procedures in Latin America and the Caribbean countries, classified by age and weight groups. The study was conducted in the framework of the Optimization of Protection in Pediatric Interventional Radiology in Latin America and the Caribbean program coordinated by the World Health Organization and the Pan American Health Organization in cooperation with the International Atomic Energy Agency. The first step of the program was focused on pediatric IC. Dose data from diagnostic and therapeutic procedures were collected between December 2020 and December 2021. Regional DRLs were set as the third quartile of patient dose data (kerma area product) collected in 18 hospitals from 10 countries in an initial sample of 968 procedures. DRLs were set for four age bands and five weight ranges. The values obtained for the four age bands (<1 yr, 1 to <5 yr, 5 to <10 yr and 10 to <16 yr) were 2.9, 6.1, 8.8 and 14.4 Gy cm²for diagnostic procedures, and 4.0, 5.0, 10.0 and 38.1 Gy cm²for therapeutic procedures, respectively. The values obtained for the five weight bands (<5 kg, 5 to <15 kg, 15 to <30 kg, 30 to <50 kg and 50 to <80 kg) were 3.0, 4.5, 8.1, 9.2 and 26.8 Gy cm²for diagnostic procedures and 3.7, 4,3, 7.3, 16.1 and 53.4 Gy cm²for therapeutic procedures, respectively. While initial data were collected manually as patient dose management systems (DMSs) were not available in most of the hospitals involved in the program, a centralized automatic DMS for the collection and management of patient dose indicators has now been introduced and is envisaged to increase the sample size. The possibility of alerting on high dose values and introducing corrective actions will help in optimization.

First report of group A rotavirus and bovine coronavirus associated with neonatal calf diarrhea in the northwest of Argentina

Group A rotavirus (RVA) and bovine coronavirus (BCoV) are the two main viral enteropathogens associated with neonatal calf diarrhea. The aim of the present survey was to investigate the epidemiology and the role of RVA and BCoV in the presentation of dairy and beef calf diarrhea in Lerma Valley of Salta province, within the Northwest region of Argentina. Stool samples of calves with or without diarrhea younger than 2 months of age were collected from 19 dairy farms and 20 beef farms between the years 2014 and 2016. Stool samples were screened for RVA and BCoV detection by ELISA. Heminested multiplex RT-PCR was used for RVA typing and RT-PCR to confirm BCoV. Positive samples were submitted to sequencing analysis. Bovine RVA and BCoV were circulating in 63% (12/19) and 10.52% (2/19) of the dairy farms, respectively, where 9.5% (46/484) of the calves were positives to RVA and 0.4% (2/484) to BCoV. In beef herds, RVA was detected in 40% (8/20) of the farms and in 6.75% (21/311) of the calves, without positives cases of BCoV. Molecular analysis showed that in dairy farms, G6P[11] and G10P[11] were the prevalent RVA strains, while in beef farms, G10P[11] was the prevalent. The main finding was the detection for the first time of a G15P[11] causing diarrhea in beef calves of Argentina that represents a new alert to be consider for future vaccine updates. Analysis of detected BCoV showed that it is related to the other circulating strains of Argentina.

Radiologic assessment of gastric emptying of water-soluble contrast media: New data security from a longitudinal study

BACKGROUND AND OBJECTIVES

Practice guidelines for preoperative fasting have not clearly established the fasting time needed after oral administration of water-soluble contrast media. The aim of this study was to determine the time required for the gastric emptying during the water-soluble contrast media in patients with acute abdominal pain.

METHODS

This prospective longitudinal study included sixty-eight patients older than 18 years of age with acute abdominal pain, who required a water-soluble contrast media enhanced abdominal computed tomography study. Plain radiographs were obtained hourly until complete the gastric emptying. Patients with probable bowel obstruction were not included in the study.

RESULTS

A total of 31 (45,6%), 54 (79,4%), and 64 (94,1%) patients achieved a complete gastric clearance of barium in 1, 2 and 3 hours, respectively. All patients achieved complete emptying of water-soluble contrast media within 6 hours. Gastric emptying time was not associated with gender (P=0,44), body mass index (P=.35), fasting time prior to water-soluble contrast media intake (P=0,12), administration of opioids in the emergency room (P=0,7), and the presence of comorbidities (P=0,36).

CONCLUSION

Ninety-four percent of the patients with acute abdominal pain achieved complete gastric emptying within 3hours after the administration of water-soluble contrast media. All of them achieved complete gastric emptying within 6hours. The results suggested 6hours after oral intake of the contrast media is enough to complete transit of water-soluble contrast media through the stomach and avoid unnecessary risks.

Comparison of two angiographic systems in paediatric interventional cardiology

The aim of this work was to analyse the radiation dose for patients and staff between X-ray systems, a new biplane with flat-panel detectors (FDs) and a conventional system equipped with image intensifier (II). Entrance surface air kerma (ESAK) and scatter doses were measured on polymethyl methacrylate (PMMA) phantoms of different thicknesses (from 4 to 16 cm). The ESAK values for the different acquisition modes and PMMA thicknesses were higher for the II in comparison with FDs. For the II, the scatter dose rates ranged from 0.67 to 12.2 mSv h(-1) at the eye position of the cardiologist during fluoroscopy and cine modes. At the lower extremities, these values were 1.11 and 24.24 mSv h(-1). In the case of the FDs, these values ranged from 0.24 to 0.67 mSv h(-1) for eye lens and from 0.73 to 2.01 mSv h(-1) for the position of cardiologist's ankle. The newly installed X-ray system showed an average reduction factor of up to 9.7 times for ESAK values. For the staff with an average reduction factor of 15.9 times at the eye position during fluoroscopy and cine modes, no protective tools are used. At the lower extremities, this value was 7.6 times.

An update on the use of melatonin as a stroke therapeutic

Delivery of melatonin and targeting melatonin receptors pose as neuroprotective strategies for stroke therapy. The potential of melatonin-based therapeutics for clinical application in stroke patients requires translational research to guide the conduct of clinical trials. We review recent preclinical and clinical data that support the use of melatonin for stroke.

Bcl-2 and CCND1/CDK4 expression levels predict the cellular effects of mTOR inhibitors in human ovarian carcinoma

Molecular markers enabling the prediction of sensitivity/resistance to rapamycin may facilitate further clinical development of rapamycin and its derivatives as anticancer agents. In this study, several human ovarian cancer cell lines (IGROV1, OVCAR-3, A2780, SK-OV-3) were evaluated for susceptibility to rapamycin-mediated growth inhibition. The differential expression profiles of genes coding for proteins known to be involved in the mTOR signaling pathway, cell cycle control and apoptosis were studied before and after drug exposure by RT-PCR. In cells exposed to rapamycin, we observed a dose-dependent downregulation of CCND1 (cyclin D1) and CDK4 gene expression and late G1 cell cycle arrest. Among these cell lines, SK-OV-3 cells resistant to both rapamycin and RAD001 were the sole to show the expression of the anti-apoptotic gene Bcl-2. Bcl-2/bclxL-specific antisense oligonucleotides restored the sensitivity of SK-OV-3 cells to apoptosis induction by rapamycin and RAD001. These results indicate that baseline Bcl-2 expression and therapy-induced downexpression of CCND1 and CDK4 may be regarded as molecular markers enabling the prediction and follow-up of the cellular effects on cell cycle and apoptosis induction of rapamycin in ovarian cancer. Furthermore, strategies to down regulate Bcl-2 in ovarian cancer may prove useful in combination with rapamycin or RAD001 for ovarian cancer.

mTOR-targeted therapy of cancer with rapamycin derivatives

Rapamycin and its derivatives (CCI-779, RAD001 and AP23576) are immunosuppressor macrolides that block mTOR (mammalian target of rapamycin) functions and yield antiproliferative activity in a variety of malignancies. Molecular characterization of upstream and downstream mTOR signaling pathways is thought to allow a better selection of rapamycin-sensitive tumours. For instance, a loss of PTEN functions results in Akt phosphorylation, cell growth and proliferation; circumstances that can be blocked using rapamycin derivatives. From recent studies, rapamycin derivatives appear to display a safe toxicity profile with skin rashes and mucositis being prominent and dose-limiting. Sporadic activity with no evidence of dose-effect relationship has been reported. Evidence suggests that rapamycin derivatives could induce G1-S cell cycle delay and eventually apoptosis depending on inner cellular characteristics of tumour cells. Surrogate molecular markers that could be used to monitor biological effects of rapamycin derivatives and narrow down biologically active doses in patients, such as the phosphorylation of P70S6K or expression of cyclin D1 and caspase 3, are currently evaluated. Since apoptosis induced by rapamycin is blocked by BCL-2, strategies aimed at detecting human tumours that express BCL-2 and other anti-apoptotic proteins might allow identification of rapamycin-resistant tumours. Finally, we discuss current and future placements of rapamycin derivatives and related translational research into novel therapeutic strategies against cancer.