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Inherited Abnormalities in Thyroid Hormone Transport Proteins
Published in Geraldo Medeiros-Neto, John Bruton Stanbury, Inherited Disorders of the Thyroid System, 2019
Geraldo Medeiros-Neto, John Bruton Stanbury
Refetoff2 defines complete TBG deficiency when the serum concentration of TBG is less than 0.5 μg/dl. This is the current limit of detection by the most sensitive assays.15 It affects individuals from all races and ethnic backgrounds and the incidence is around 1 to 15,000 newborn males. Heterozygous females (two X chromosomes) usually express the defect partially by having approximately half the normal concentration of TBG (Figure 1). None of the subjects with TBG-CD belonging to 16 unrelated families had detectable TBG in serum.2
Radiation Detection and Measurement
Published in Shaheen A. Dewji, Nolan E. Hertel, Advanced Radiation Protection Dosimetry, 2019
The lower limit of detection, is the lowest quantity of a value that can be distinguished from the absence of that value within a stated confidence limit. An estimate of the lower limit of detection for a dosimetric measurement can be given by evaluating the mean dose equivalent values from unirradiated and irradiated dosimeters, denoted as and , respectively. Standard deviations for these quantities and are calculated and the lower limit of detection is computed using:
Development and Evaluation
Published in Joseph Chamberlain, The Analysis of Drugs in Biological Fluids, 2018
Because most drugs developed today are administered in very small doses, the analyst is continually being challenged to devise methods of detection and measurement of very small concentrations of drug. As explained in Chapter 1, for pharmacokinetic studies, it is at the low level of drug that the quantitation becomes extremely important. Thus the limit of detection obtained using a particular method is of prime importance in such studies. Many reports use the term sensitivity for this parameter; however, sensitivity is also used to describe the slope of a concentration-response line (i.e., a measure of how sensitive the end point is to the change in concentration). Thus the author recommends that the term limit of detection is more appropriate in this context. Of all the parameters used to characterize a method, it is probably the one that has the most varied treatment from analysts, so that a statement that “the sensitivity is x ng ml−1,” should only be accepted in the context of the definition given by the author of that particular paper or its description.
COVID-19 subphenotypes at hospital admission are associated with mortality: a cross-sectional study
Published in Annals of Medicine, 2023
Kathryn Dubowski, Giovanna T. Braganza, Anne Bozack, Elena Colicino, Nicholas DeFelice, Laura McGuinn, Duncan Maru, Alison G. Lee
We obtained clinical and laboratory data from the first 24 h of the patient’s first hospitalization that met inclusion criteria. Only variables with data available from at least 60% of participants or variables with a strong biological basis based on prior studies [erythrocyte sedimentation rate (ESR), interleukin 6 (IL-6), interleukin 1 beta (IL-1B)] were included. For variables with repeated observations, we identified the worst value recorded within 24 h of admission. Clinical variables included lowest oxygen saturation, lowest systolic and diastolic blood pressure, highest heart rate, and highest temperature within the first 24 h. Laboratory variables examined included inflammatory markers [C-reactive protein (CRP), ESR, IL-6, IL-1B, lactate dehydrogenase (LDH), procalcitonin, ferritin]; hematologic markers [white blood cell (WBC), hemoglobin, platelets, d-dimer, fibrinogen, prothrombin time (PT), partial thromboplastin time (PTT)); cardiac markers (troponin, brain natriuretic peptide (BNP)]; and renal and hepatic markers (alanine transaminase (ALT), aspartate aminotransferase (AST), albumin, total bilirubin, sodium, potassium, calcium, bicarbonate, blood urea nitrogen (BUN), creatinine, anion gap, glucose. Laboratory values above the laboratory-defined limit of detection were assigned the value at the limit of detection.
Development and validation of HPLC method for simultaneous determination of Leflunomide and folic acid in the nanoparticulate system by reversed-phase HPLC
Published in Drug Development and Industrial Pharmacy, 2023
Bazla Siddiqui, Haroon Ahmed, Ihsan-ul- Haq, Asim.ur. Rehman, Naveed Ahmed
A facile reversed phase HPLC technique was developed to simultaneously detect and analyze both LEF and FA from the nanocarriers for the first time. In addition to the novelty of method to simultaneously detect both components in less retention time, the method is also simple, fast, robust, sensitive, precise, and produced reproducible results in accordance with the ICH guidelines. The response of the detector was found to be linear for both of the components at a wider concentration range. Moreover, the lower value of limit of detection enabled this technique to analyze the samples at relatively lower concentrations. No interference of the formulation matrix was observed, and method was successfully employed for determination of entrapment efficiency and loading capacity. Another advantage of the proposed developed method was the utilization of same mobile phase for determination of both components from the nanocarriers. In comparison to the previously developed method of Leflunomide detection, the method produced precise results at a relatively shorter time period. Hence, the method can be recommended for evaluation of further parameters of the prepared nanocarriers, e.g. dissolution studies, release studies. In future, the method can also be utilized for evaluating the concentration of both agents in serum and plasma for in vivo drug analysis and for monitoring pharmacokinetic drug profile.
Evaluation of association between parameters related to penetration into cerebrospinal fluid and the microbiological efficacy of vancomycin in patients with bacterial meningitis
Published in Journal of Chemotherapy, 2022
Masayuki Ishikawa, Masashi Uchida, Shingo Yamazaki, Yuki Shiko, Yohei Kawasaki, Takaaki Suzuki, Yasuo Iwadate, Itsuko Ishii
VMser and VMCSF were measured by a chemiluminescence immunoassay with an ARCHITECT® analyzer (Abbott Laboratories, Irving, TX). The method was fully validated over a concentration range of 3.0–100.0 μg/mL. The lower limit of quantification and the lower limit of detection were 3.0 μg/mL and 0.24 μg/mL, respectively. SA concentrations were measured by the bromocresol green or bromocresol purple method. The SA value measured by the bromocresol green method is known to be about 0.3 mg/dL higher than that measured by the bromocresol purple method. Therefore, if the SA was measured by the bromocresol green method, we subtracted 0.3 mg/dL from the measured value based on the guidelines [14]. CSF proteins and CSF glucose concentrations were measured by the pyrogallol red and hexokinase methods, respectively. CSF cell counts were performed manually. The MIC for bacteria was determined via the broth microdilution method of the Clinical and Laboratory Standards Institute. Creatinine clearance was calculated by the Cockcroft–Gault formula, using actual body weight [15].