Conversion factors for determining organ doses received by paediatric patients in high-resolution single slice computed tomography with narrow collimation

Estimations of organ doses D_T received during computed tomographic examinations are usually performed by applying conversion factors to basic dose indicators like the computed tomography dose index (CTDI) or the dose-length-product (DLP). In addition to the existing conversion factors for beam apertures of 5 mm or 10 mm, we present new DLP-D_T conversion factors adapted to high-resolution CT (HRCT) examinations of infants and young children with beam apertures of the order of 1 mm and under consideration of bow tie filtration. Calculations are performed on mathematical MIRD phantoms for an age range from 0, 1, 5, 10, 15 up to (for comparison) 30 years by adapting PCXMC, a Monte Carlo algorithm originally developed by STUK (Helsinki, Finland) for dose reconstructions in projection radiography. For this purpose, each single slice CT examination is approximated by a series of corresponding virtual planar radiographies comprising all focus positions. The transformation of CT exposure parameters into exposure parameters of the series of corresponding planar radiographies is performed by a specially developed algorithm called XCT. The DLP values are evaluated using the EGSRay code. The new method is verified at a beam aperture of 10 mm by comparison with formerly published conversion factors. We show that the higher spatial resolution leads to an enhanced DLP-D_T conversion factor if a small organ (e. g. thyroid gland, mammae, uterus, ovaries, testes) is exactly met by the chosen CT slice, while the conversion factor is drastically reduced if the chosen CT slice is positioned above or below the organ. This effect is utilized for dose-saving examinations with only a few single slices instead a full scan, which technique is applied in about 10% of all paediatric chest CT examinations.     

Lymph node 8a as a prognostic marker for poorer prognosis in pancreatic and periampullary carcinoma

Objectives: An investigation of patients with pancreatic carcinoma aims to identify those who will benefit from surgery. Physical examination, radiology and laboratory findings are helpful. Most prognostic markers, such as lymph node status, micro metastasis and tumour differentiation, are not preoperatively accessible. Metastatic disease in lymph node 8a (Ln8a) in patients operated for pancreatic carcinoma has been reported to be a predictor of shorter overall survival (OS). This lymph node can be assessed preoperatively through resection (possibly even with laparoscopy) and subsequent histopathology. The value of the procedure is disputed. The aim of this study is to investigate whether metastatic disease in Ln8a is a predictor of decreased OS.

Materials and methods: In patients with suspected pancreatic or periampullary carcinoma, who were operated with pancreatoduodenectomy (PD), Ln8a was separately resected and analysed with standard and immuno-histochemical methods. Patients with or without metastasis in Ln8a were compared regarding OS.

Results: Between 2008 and 2011, 122 consecutive patients were eligible and 87 were resected and had LN8a analysed separately. Sixteen patients were Ln8a?+?and 71 were Ln8a-. Patients with Ln8a?+?had a significantly reduced median OS as compared to patients with Ln8a– (0.74 (95% CI 0.26–1.26) versus 5.91 years (95% CI 2.91–), p?Conclusion: Ln8a?+?was associated with a marked reduction of OS, indicating a possible role in the future preoperative workup in patients with a suspicion of pancreatic cancer.     

Evaluation of a disease risk index for adult patients undergoing umbilical cord blood transplantation for haematological malignancies

A disease risk index (DRI) has been defined for stratifying heterogeneous cohorts of patients undergoing allogeneic haematopoietic stem cell transplantation (HSCT). This index defines 4 distinct groups with different outcomes, dividing patients by disease type and status and considering cytogenetics for acute myeloid leukaemia and myelodysplastic syndromes (MDS). Recently, the DRI has been refined to include rare diseases and improve MDS stratification by blast percentage and response to prior therapy. Previous reports on DRI include only a small number of UCBT recipients. The current study aims to determine the applicability of the DRI for patients undergoing unrelated cord blood transplantation (UCBT). We retrospectively analysed 2530 adults receiving UCBT between 2004 and 2014. Diagnosis was acute leukaemia (AL) in 66% of the cases. Overall survival (OS) at 2 years was 56 ± 3% for patients with low DRI (n = 352), 46 ± 1% for intermediate DRI (n = 1403), 28 ± 2% for high (n = 489) and 20 ± 4% for very high DRI (n = 109) (P < 0·001). In the multivariate model, DRI remained an independent risk factor for OS. Similar findings were observed for PFS and DRI. Our results show the applicability of DRI for stratifying UCBT recipients and confirm the prognostic value of this simple and robust tool in this setting.     

中医药方法整合西医药指标相关问题讨论

中医方法整合西医指标的可行性及必要性以及整合的内容、步骤、对象、方法等相关问题的讨论。     

Glycemic index and phenolics of partially-baked frozen bread with sourdough

Different lactic acid bacteria starters were used to prepare sourdough to make partially-baked frozen wholemeal wheat bread. The sourdough was prepared with a pure culture of Lactobacillus plantarum or with commercial starters containing Lactobacillus brevis combined with Saccharomyces cerevisiae var. chevalieri (LV4), Lactobacillus fermentum (PL1), or Lactobacillus fermentum with phytase (PL3). We determined the acetic and lactic acid concentrations in sourdough, bread chemical composition, total phenolics content and glycemic index (GI) in vivo. Depending on the starter, the lactic to acetic acid ratio in the sourdough was significantly different. The GI of control bread without sourdough (70) was significantly higher than that of bread containing sourdough prepared with LV4 starter (50), PL1 starter (56) or PL3 starter (56), but not from bread with L. plantarum sourdough (60). The addition of 10% sourdough with a lower molar ratio of lactic to acetic acid ( ≤ 4) and higher total phenolics content is preferable for generating bread with medium and low GI.     

Some nutritional properties of the seeds of three Mucuna species

The seeds of Mucuna nivea, M. pruriens and M. utilis showed ash 4.3-5.1%, oil 4.9-5.5%, protein 25.9-27.5%, L-dopa 3.6-4.2%, trypsin 28.5-39.7 mg/g and chymotrypsin inhibitor activity 19.3-24.6 mg/g. The trypsin and chymotrypsin inhibitor activity increased in pod hull and seeds while the amount of protein increased in seeds and decreased in pod hull with maturity. The essential amino acid profile was comparable to the FAO pattern (lysine 6.0-6.4%). The fatty acid composition had total unsaturated acids 51.9-55.9%, but were poor in oil contents.