| 1. |
- Beal, Jacob, et al.
(författare)
-
Robust estimation of bacterial cell count from optical density
- 2020
-
Ingår i: Communications Biology. - : Springer Science and Business Media LLC. - 2399-3642. ; 3:1
-
Tidskriftsartikel (refereegranskat)abstract
- Optical density (OD) is widely used to estimate the density of cells in liquid culture, but cannot be compared between instruments without a standardized calibration protocol and is challenging to relate to actual cell count. We address this with an interlaboratory study comparing three simple, low-cost, and highly accessible OD calibration protocols across 244 laboratories, applied to eight strains of constitutive GFP-expressing E. coli. Based on our results, we recommend calibrating OD to estimated cell count using serial dilution of silica microspheres, which produces highly precise calibration (95.5% of residuals <1.2-fold), is easily assessed for quality control, also assesses instrument effective linear range, and can be combined with fluorescence calibration to obtain units of Molecules of Equivalent Fluorescein (MEFL) per cell, allowing direct comparison and data fusion with flow cytometry measurements: in our study, fluorescence per cell measurements showed only a 1.07-fold mean difference between plate reader and flow cytometry data.
|
|
| 2. |
- Niklasson, Bo, et al.
(författare)
-
Association of zoonotic Ljungan virus with intrauterine fetal deaths
- 2007
-
Ingår i: Birth defects research. Clinical and molecular teratology. - : Wiley. - 1542-0752 .- 1542-0760. ; 79, s. 488-493
-
Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: It has recently been shown that Ljungan virus (LV) is associated with disease in its wild rodent reservoir. In addition, it has been demonstrated that LV causes malformations and perinatal death in a mouse model. The question was therefore raised whether LV is a zoonotic agent in humans. METHODS: Population fluctuations of native rodents in Sweden were compared to the incidence of intrauterine fetal deaths (IUFDs) using the Swedish national hospitalization database. Formalin-fixed tissues from cases of IUFD were investigated using LV-specific immunohistochemistry. RESULTS: Variation in the incidence of IU-FDs closely tracked the fluctuations in native rodent populations. LV was detected in the brain tissue in 4 of 10 cases of IUFDs investigated by immunochemistry. LV was also detected in the placenta in 5 of the 10 IUFD cases, but in none of 20 placentas from normal pregnancies. CONCLUSIONS: LV may play an important role in IUFDs.
|
|
| 3. |
- Schuit, Ewoud, et al.
(författare)
-
Effectiveness of electronic fetal monitoring with additional ST analysis in vertex singleton pregnancies at > 36 weeks of gestation: an individual participant data metaanalysis
- 2013
-
Ingår i: American Journal of Obstetrics and Gynecology. - : Elsevier BV. - 1097-6868 .- 0002-9378. ; 208:3, s. 1-187
-
Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: The purpose of this study was to assess the effectiveness of electronic fetal monitoring (EFM) alone and with additional ST analysis (EFM + ST) in laboring women with a singleton term pregnancy that is in cephalic presentation in the prevention of metabolic acidosis by the application of individual patient data metaanalysis. STUDY DESIGN: We conducted an individual patient data metaanalysis using data from 4 randomized trials, which enabled us to account for missing data and investigate relevant subgroups. The primary outcome was metabolic acidosis, which was defined as an umbilical cord-artery pH <7.05 and a base deficit that had been calculated in the extra cellular fluid compartment >12 mmol/L. We performed 8 explanatory subgroup analyses for 8 different endpoints. RESULTS: We analyzed data from 12,987 women and their newborn infants. Metabolic acidosis was present in 57 women (0.9%) in the EFM + ST group and 73 women (1.1%) in the EFM alone group (relative risk [RR], 0.76; 95% CI, 0.53-1.10). Compared with EFM alone, the use of EFM + ST resulted in a reduction in the frequency of instrumental vaginal deliveries (RR, 0.90; 95% CI, 0.83-0.99) and fetal blood samples (RR, 0.49; 95% CI, 0.44-0.55). Cesarean delivery rates were comparable between both groups (RR, 0.99; 95% CI, 0.91-1.09). Subgroup analyses showed that EFM + ST resulted in fewer admissions to a neonatal intensive care unit for women with a duration of pregnancy of >41 weeks (RR, 0.61; 95% CI, 0.39-0.95). CONCLUSION: EFM + ST does not reduce the risk of metabolic acidosis, but it does reduce the need for instrumental vaginal deliveries and fetal blood sampling.
|
|
