| 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. |
- White, Paul J, et al.
(författare)
-
Identifying the core concepts of pharmacology education: A global initiative.
- 2022
-
Ingår i: British journal of pharmacology. - : Wiley. - 0007-1188 .- 1476-5381. ; 180:9, s. 1197-1209
-
Tidskriftsartikel (refereegranskat)abstract
- In recent decades, a focus on the most critical and fundamental concepts has proven highly advantageous to students and educators in many science disciplines. Pharmacology, unlike microbiology, biochemistry, or physiology, lacks a consensus list of such core concepts.We sought to develop a research-based, globally relevant list of core concepts that all students completing a foundational pharmacology course should master. This two-part project consisted of exploratory and refinement phases. The exploratory phase involved empirical data mining of the introductory sections of five key textbooks, in parallel with an online survey of over 200 pharmacology educators from 17 countries across six continents. The refinement phase involved three Delphi rounds involving 24 experts from 15 countries across six continents.The exploratory phase resulted in a consolidated list of 74 candidate core concepts. In the refinement phase, the expert group produced a consensus list of 25 core concepts of pharmacology.This list will allow pharmacology educators everywhere to focus their efforts on the conceptual knowledge perceived to matter most by experts within the discipline. Next steps for this project include defining and unpacking each core concept and developing resources to help pharmacology educators globally teach and assess these concepts within their educational contexts.
|
|
| 3. |
- Withrow, Diana R., et al.
(författare)
-
Pooled Analysis of Meningioma Risk Following Treatment for Childhood Cancer
- 2022
-
Ingår i: JAMA Oncology. - : American Medical Association (AMA). - 2374-2437. ; 8:12, s. 1756-1764
-
Tidskriftsartikel (refereegranskat)abstract
- Importance: Meningioma is the most common subsequent neoplasm following cranial irradiation among survivors of childhood cancer, but there are still uncertainties regarding the magnitude of the radiation dose-response association, potential modifiers of radiation risks, and the role of chemotherapy. Objective: To evaluate meningioma risk in survivors of childhood cancer following radiotherapy and chemotherapy and identify possible modifying factors of radiation-associated risk. Design, Setting, and Participants: This international case-control study pooled data from 4 nested case-control studies of survivors of childhood cancer diagnosed between 1942 and 2000, followed through 2016. Cases were defined as participants diagnosed with a subsequent meningioma. Controls were matched to cases based on sex, age at first cancer diagnosis, and duration of follow-up. Data were analyzed from July 2019 to June 2022. Exposures: Radiation dose (Gy) to the meningioma site and cumulative chemotherapy doses, including intrathecal and systemic methotrexate doses. Main Outcomes and Measures: The main outcome was subsequent meningioma, assessed using odds ratios (ORs) and excess odds ratios per gray (EOR/Gy). Results: The analysis included 273 survivors of childhood cancer who developed meningioma (cases) and 738 survivors who did not (controls), with a total of 1011 individuals (median [IQR] age at first cancer diagnosis 5.0 [3.0-9.2] years; 599 [59.2%] female). Median (IQR) time since first cancer was 21.5 (15.0-27.0) years. Increasing radiation dose was associated with increased risk of meningioma (EOR/Gy, 1.44; 95% CI, 0.62-3.61), and there was no evidence of departure from linearity (P =.90). Compared with survivors who were not exposed to radiation therapy, those who received doses of 24 Gy or more had more than 30-fold higher odds of meningioma (OR, 33.66; 95% CI, 14.10-80.31). The radiation dose-response association was significantly lower among patients treated at age 10 years or older compared with those treated before age 10 years (EOR/Gy, 0.57; 95% CI, 0.18-1.91 vs 2.20; 95% CI, 0.87-6.31; P for heterogeneity =.03). Risk associated with radiation remained significantly elevated 30 years after exposure (EOR/Gy, 3.76; 95% CI, 0.77-29.15). We found an increased risk of meningioma among children who had received methotrexate (OR, 3.43; 95% CI, 1.56-7.57), but no evidence of a dose-response association or interaction with radiation dose. Conclusions and Relevance: These findings suggest that the meninges are highly radiosensitive, especially for children treated before age 10 years. These results support the reduction in whole-brain irradiation over recent decades and the prioritization of approaches that limit radiation exposure in healthy tissue for children. The persistence of elevated risks of meningiomas for 30 years after cranial radiotherapy could help inform surveillance guidelines..
|
|
| 4. |
- Yang, Muyi, et al.
(författare)
-
Novel loss-of-function variant in DENND5A impedes melanosomal cargo transport and predisposes to familial cutaneous melanoma
- 2022
-
Ingår i: Genetics in Medicine. - : Elsevier BV. - 1098-3600 .- 1530-0366. ; 24:1, s. 157-169
-
Tidskriftsartikel (refereegranskat)abstract
- Purpose: More than half of the familial cutaneous melanomas have unknown genetic predisposition. This study aims at characterizing a novel melanoma susceptibility gene. Methods: We performed exome and targeted sequencing in melanoma-prone families without any known melanoma susceptibility genes. We analyzed the expression of candidate gene DENND5A in melanoma samples in relation to pigmentation and UV signature. Functional studies were carried out using microscopic approaches and zebrafish model. Results: We identified a novel DENND5A truncating variant that segregated with melanoma in a Swedish family and 2 additional rare DENND5A variants, 1 of which segregated with the disease in an American family. We found that DENND5A is significantly enriched in pigmented melanoma tissue. Our functional studies show that loss of DENND5A function leads to decrease in melanin content in vitro and pigmentation defects in vivo. Mechanistically, harboring the truncating variant or being suppressed leads to DENND5A losing its interaction with SNX1 and its ability to transport the SNX1-associated vesicles from melanosomes. Consequently, untethered SNX1-premelanosome protein and redundant tyrosinase are redirected to lysosomal degradation by default, causing decrease in melanin content. Conclusion: Our findings provide evidence of a physiological role of DENND5A in the skin context and link its variants to melanoma susceptibility.
|
|
