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We assessed the impacts of Tanzania's adolescent-focused Cash Plus intervention on depression. In this pragmatic cluster-randomized controlled trial, 130 villages were randomly allocated to an intervention or control arm (1:1). Youth aged 14-19 years living in households receiving governmental cash transfers were invited to participate. The intervention included an intensive period (a 12-session course) and an aftercare period (9 months of mentoring, productive grants, and strengthened health services). We examined intervention impacts on a depressive symptoms scale (10-item Center for Epidemiologic Studies Depression Scale score (range, 0-30)) and rates of depressive symptomatology (score ≥10 points on the scale), recorded at study baseline (April-June 2017), midline (May-July 2018), and endline (June-August 2019). Using intention-to-treat methodology, we employed logistic and generalized linear models to estimate effects for binary and continuous outcomes, respectively. Quantile regression was used to estimate effects across the scale. From 2,458 baseline participants, 941 intervention and 992 control adolescents were reinterviewed at both follow-ups. At endline, the intervention reduced the odds of depressive symptomatology (adjusted odds ratio = 0.67, 95% confidence interval: 0.52, 0.86), with an undetectable mean scale difference (risk difference = -0.36, 95% confidence interval: -0.84, 0.11). Quantile regression results demonstrated an intervention effect along the upper distribution of the scale. Integration of multisectoral initiatives within existing social protection systems shows potential to improve mental health among youth in low-resource settings., (© The Author(s) 2022. Published by Oxford University Press on behalf of the Johns Hopkins Bloomberg School of Public Health.)

We describe an improved enzymatic ultraviolet absorbance method for assaying creatinine in serum, plasma, and urine. Creatinine is hydrolyzed by creatinine iminohydrolase (EC 3.5.4.21) to ammonia and N-methylhydantoin. The ammonia produced combines with 2-oxoglutarate and NADPH in the presence of glutamate dehydrogenase to yield glutamate and NADP+. The consumption of NADPH, measured by a two-point fixed-time assay, is proportional to the amount of creatinine in the sample. The assay is carried out in two steps: The first step eliminates background absorbance in hyperlipemic samples and endogenous ammonia through a "clearing system" and an isocitrate dehydrogenase-based "ammonia scavenger system"; the second step starts creatinine measurement. The method affords a simple, rapid, and sensitive assay with good precision and extended linearity; it employs working solutions stable at least 4 months. Test results compare closely with those of the isotope dilution-mass spectrometry Definitive Method, the HPLC procedure, and the fuller's earth method. The proposed method is not subject to interference from several metabolites or from the 72 drugs tested. Because it is easily automated, the method is suitable for routine work in clinical laboratories.

We assessed the analytical performance of the Axon system (Bayer Diagnostici), according to the European Committee for Clinical Laboratory Standards guidelines, for assay of 12 analytes: cholesterol, creatinine, glucose, total protein, urea, uric acid, alkaline phosphatase, alpha-amylase, aspartate aminotransferase, creatine kinase, sodium, and potassium. The field evaluation lasted approximately 5 months and involved the collection of approximately 10,000 data points with the Axon. The following results were obtained: The highest CVs for controls and human sera at different concentration/activity values were 2.2% for within-run imprecision (n = 60; 3 days, pooled estimate) and 3.5% for the between-day imprecision (n = 20 days). Close correlation was found with results for patients' specimens assayed with comparative instruments (Hitachi 717 for substrates and enzymes, Beckman Synchron EL/E4A for electrolytes). No drift was observed during 8 h of operation. The linearity range was broad, sometimes exceeding the manufacturer's claims. No sample-, reagent-, or cuvette-related carryover was found. Measurement of control sera gave results within +/- 5% of the assigned values. We conclude that good reliability and practicability make the Axon system suitable for laboratories with various needs.

A single reagent, containing cholesterol oxidase, cholesterol esterase, peroxidase, 4-hydroxybenzoate, and 4-aminophenazone, is used in determining serum cholesterol. Analysis time is 15 min, and the standard curve is linear to 6.0 g/liter. Analytical recovery of cholesterol was 100.1 +/- 0.4%. Within-run precision (CV) was less than or equal to 1.4 1.4%, between-run less than or equal to 4.8%. Comparison with results by a Liebermann Burchard method [Clin. Chim. Acta 5, 637 (1960)] gave a linear regression of y = 1.08x--0.05, with a correlation coefficient (r) of 0.985. Comparison with the Roeschlau enzymic method [J. Clin. Chem. Clin. Biochem, 12, 226 (1974)] gave y = 1.02x + 0.01 (r = 0.958). Comparison with the enzymic method of Allain et al. [Clin. Chem. 20, 470 (1974)] gave y = 1.01x--0.00 (r = 0.995). The following substances do not interfere up to the indicated concentrations (mg/liter): hemoglobin (5000), bilirubin (100), reduced glutathione (150), l-cysteine (400), urea (3000), creatinine (200), uric acid (200), d-glucose (10000), L-ascorbic acid (50), acetylsalicylic acid (500), L-DOPA (10), ergothioneine (1000), 2,5-dihydroxybenzoic acid (20), and 3,4-dihydroxybenzoic acid (10). Stored in an amber-colored bottle, the working reagent is stable for three months at 2--8 degrees C and for three weeks at 25 degrees C.

We describe an assay for creatinine in which it is converted by creatinine iminohydrolase (EC 3.5.4.21) into ammonia and N-methylhydantoin. The ammonia is subsequently assayed by use of alpha-ketoglutarate and glutamate dehydrogenase (EC 1.4.1.3). Use of NADPH as coenzyme eliminates all interferences from endogenous reactions. Endogenous ammonia in the sample is eliminated during a preincubation. The reaction reaches the endpoint in 15 min at working temperatures of 20-37 degrees C. No sample blank or reagent blank is needed. The standard curve is linear at least to 884 mumol (100 mg) of creatinine per liter. Average analytical recovery of creatinine in serum and urine is 99%. Within-run and between-run CVs are less than or equal to 2% and less than or equal to 6% for creatinine values of 335 mumol/L (38 mg/L) and 80 mumol/L (0 mg/L), respectively. Results by the described method (y) compare well with those by Jaffé's kinetic test (y = 1.01x -- 12.8), Berthelot/AutoAnalyzer method after treatment with immobilized creatinine iminohydrolase (y = 0.987x -- 13.2), Jaffé's test run on the SMA 12/60 (y = 1.011x -- 5.8), the Wahlefeld method (y = 1.014x -- 0.88), and Jaffé's test after deproteinization and absorption on fuller's earth (y = 0.985x -- 3.08). The method may be suitable for discrete, including centrifugal, automation.

We describe a new colorimetric method for measuring ethanol in plasma by use of a peroxidase-coupled assay system and alcohol oxidase (EC 1.1.3.13) from Pichia species. Absorptivity is low enough to give useful results without sample dilution. The procedure is also applicable to saliva samples and utilizes only one working reagent. The absorbance of the blue dye that is formed is measured at 600 nm. The standard curve for the method is linear for ethanol concentrations up to 4 g/L. Average analytical recovery of ethanol in human plasma exceeded 99%. Within-run and between-run CVs were less than 2.45% and less than 1.92%, respectively. Results correlate very well with those by gas chromatography (r = 0.9977). The method is adaptable to automation.

In this direct colorimetric procedure, serum triglycerides are hydrolyzed by lipase, and the released glycerol is assayed in a reaction catalyzed by glycerol kinase and L-alpha-glycerol-phosphate oxidase in a system that generates hydrogen peroxide. The hydrogen peroxide is monitored in the presence of horseradish peroxidase with 3,5-dichloro-2-hydroxybenzenesulfonic acid/4-aminophenazone as the chromogenic system. The high absorbance of this chromogen system at 510 nm affords useful results with a sample/reagent volume ratio as low as 1:150, and a blank sample measurement is not needed. A single, stable working reagent is used; the reaction is complete in 15 min at room temperature. The standard curve is linear for triglyceride concentrations as great as 13.6 mmol/L. Average analytical recovery of triglycerides in human sera is 100.1%, and within-run and between-run precision studies showed CVs of less than or equal to 1.6 and less than or equal to 3.0%, respectively. The method is suitable for automation.

We describe a new colorimetric method for measuring creatinine in serum and urine. Creatinine hydrolysis is catalyzed by creatinine amidohydrolase, and the creatine so produced is assayed in reactions catalyzed sequentially by creatine amidinohydrolase and sarcosine oxidase in a system that generates hydrogen peroxide. The hydrogen peroxide is measured at 510 nm in a reaction catalyzed by horseradish peroxidase, with 3,5-dichloro-2-hydroxybenzenesulfonic acid/4-aminophenazone as the chromogen. This series of reactions is complete in 30 min at room temperature. A blank sample measurement corrects for endogenous creatine. The standard curve is linear for creatinine concentrations as great as 2.21 mmol/L. Analytical recovery of creatinine in human sera and urine averaged 99.8%. Within-run and between-run precision studies gave CVs of less than or equal to 3.3 and less than or equal to 4.3% for a serum with a creatinine concentration of 69 mumol/L. Results by this method agree well (r greater than 0.99) with those by both the enzymic ultraviolet method of Wahlefeld and the fuller's earth/Jaffé method.

We describe an improved colorimetric method for assays of total and direct bilirubin in serum. Bilirubin reacts with diazotized sulfanilic acid in an acidic medium to form a blue azopigment. Total bilirubin is assayed in the presence of reaction accelerators (caffeine, urea, and citric acid), direct bilirubin in their absence. The azo compound so formed is read at the same wavelength (570 nm) in both assays. A sample blank is run in parallel. Standard curves are linear for total and direct bilirubin concentrations up to 513.0 and 256.5 mumol/L, respectively. The method is characterized by (a) use of the same protocol for both assays, i.e., a one-step procedure with short reaction time (5 min at room temperature), and (b) use of a single working solution, which, refrigerated, is stable for one month. The method is reliable, yields results that compare closely with those of the classical Jendrassik--Gróf method, is suitable for routine use, and lends itself to automation.

We have explored a kinetic colorimetric method for measuring gamma-glutamyltransferase (EC 2.3.2.2) activity in serum, using L-gamma-glutamyl-3,5-dibromo-4-hydroxyanilide and glycylglycine as donor and acceptor substrates. The released product, 3,5-dibromo-4-hydroxyaniline, reacts with 2,5-dimethylphenol to produce a blue quinone monoimine in the presence of ascorbate oxidase (EC 1.10.3.3). This dye has peak absorption at 610 nm, whereas the donor substrate shows negligible absorption throughout the visible spectrum. The reaction can be run with all the reagents in a single working solution with serum as starter, or with the substrate solution as starting reagent. The sample/reagent volume ratio is 1:24. Adaptation of the method to several automated instruments gave good precision in all cases. Comparison with a method in which L-gamma-glutamyl-3-carboxy-4-nitroanilide is the donor substrate showed good correlation of results (r greater than or equal to 0.987). The dynamic range of the method exceeds the upper limits of the reference intervals for men (9-33 U/L) and women (8-25 U/L) by at least 18-fold.

A new direct colorimetric procedure for uric acid assay in serum or urine is described, utilizing a 3,5-dichloro-2-hydroxybenzene sulfonic acid/4-aminophenazone chromogenic system in the presence of horseradish peroxidase and uricase from Aspergillus flavus. This chromogen system has a high absorptivity, affording useful results with sample/reagent volume ratios as low as 0.025. The procedure is applicable to serum, plasma, or diluted urine. A single working reagent is used; the reaction is complete in less than 15 min at room temperature. The red dye formed is measured at 520 nm; a blank sample measurement is not needed. The standard curve for the method is linear for uric acid concentrations up to 1500 mumol/L. Average analytical recovery of uric acid in human sera and urine exceeded 99%; within-run and between-run precision studies showed CV's of less than or equal to 1.2 and less than or equal to 2.2%, respectively. The new procedure correlated well with the uricase/catalase and uricase/ultraviolet methods. The method is suitable for automation.