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Bone marrow of chickens of different ages was labelled locally in vivo with small amounts of ³H.thymidine directly into the bone marrow. Using autoradiography and a radiochemical technique, bone marrow-derived cells were demonstrated in the thymic medulla, the bursa of Fabricius, the splenic red pulp, and the cecal tonsil and in the bone marrow from locations other than the labelled ones. Considerable numbers of bone marrow cells were found in the bursa of chickens labelled on the day of hatching, but hardly ever in older animals. Therefore, these cells probably demonstrate traffic of progenitor cells for the bursal cell line, No bone marrow-derived cells could be localized in the germinal centers of the spleens or the cecal tonsils. [ABSTRACT FROM AUTHOR]

Background: This study compares glomerular filtration rate (GFR) equations in children based on standardized cystatin C (CYSC) and creatinine (CREA) and their combinations with renal clearance of inulin (C-inulin)., Methods: A total of 220 children with different renal disorders were referred for C-inulin (median 84 ml/min/1.73 m(2)). Bias, precision (interquartile range, IQR), and accuracy (percentage of estimates ±30 % of C-inulin; P30) were evaluated for two cystatin C equations, CAPACYSC and BergCYSC, for creatinine equations, SchwartzCREA and GaoCREA, the arithmetic mean of CAPACYSC and SchwartzCREA (MEANCAPA+Schwartz), BergCYSC and SchwartzCREA (MEANBERG+SCHWARTZ) and the composite equation ChehadeCYSC+CREA., Results: Overall results of CAPACYSC, BergCYSC, SchwartzCREA, GaoCREA, MEANCAPA+Schwartz, MEANBERG+SCHWARTZ and ChehadeCYSC+CREA were: median bias -7.6/-4.9/-3.7/-2.3/-4.6/-4.0/-10.1 %, IQR 20.0/19.9/21.7/22.4/21.0/20.9/23.3 ml/min/1.73 m(2) and P30 86/86/80/83/89/91/83 %. The cystatin C equations, MEANCAPA+Schwartz and MEANBERG+SCHWARTZ had a more stable performance across subgroups compared with SchwartzCREA, GaoCREA and ChehadeCYSC+CREA., Conclusions: Cystatin C was the preferred filtration marker for GFR estimation in children, while the benefit of combining cystatin C and creatinine deserves further investigations.

Background: Very few studies have been published that compare plasma clearance of iohexol (Cio) with renal clearance of inulin (Cin)., Study Design: Diagnostic test study., Setting & Participants: 60 children aged 11.6 ± 4.5 years with different kidney disorders were investigated., Index Test: Plasma Cio calculated from the slope and a single point., Reference Test: Renal Cin with continuous infusion during water diuresis. Results were compared with the correlation coefficients, bias and precision, accuracy percentage, root mean square error, and intraclass correlation., Other Measurements: Measured creatinine clearance and estimated glomerular filtration rate based on serum creatinine level and height., Results: Mean Cin was 70.7 ± 41.3 (SD) mL/min/1.73 m². Mean differences between Cio and Cin were 2.65 and 2.00 mL/min/1.73 m² for the slope and single-point methods, respectively. Precision was ±16 mL/min/1.73 m² and intraclass correlation was 0.92 in both methods. Proportions of Cio within 30% of Cin were 83.3% and 86.7% for the slope and single-point methods, respectively., Limitations: A limited number of patients; no adults were studied., Conclusions: Plasma Cio shows good agreement with renal Cin., (Copyright © 2010 National Kidney Foundation, Inc. Published by Elsevier Inc. All rights reserved.)

Background: An accurate method to assess albuminuria in pregnancy is mandatory to diagnose pre-eclampsia. Twenty-four-hour urine collection is still the only universally accepted method. This is, however, a cumbersome and inconvenient method. Therefore, the present study aimed at assessing the accuracy of a spot urine albumin/creatinine ratio in pregnant women with hypertension., Material and Methods: In 54 pregnant women with blood pressure >or=140/90 mmHg, 24-h albumin excretion and subsequent albumin/creatinine ratio on morning spot urine were analyzed in the individual patients. Altogether 75 paired samples were included. Receiver operating characteristic curves, relating different albumin/creatinine ratio cut-off values to 24-h albumin excretion >300 mg were constructed. Correlations were assessed by Spearman rank correlation tests., Results: The area under the receiver operating characteristic curve was 0.985. At the optimal cut-off albumin/creatinine ratio value of 27 mg/mmol the sensitivity, specificity, positive and negative predictive value for detecting albuminuria >300 mg/24 h were: 95, 100, 100 and 86% respectively. There was a close correlation between albumin/creatinine ratio and 24-h albumin excretion values (r=0.95; p<0.001)., Conclusions: It is suggested that in most cases the more cumbersome 24-h urine collection can be replaced by the more convenient albumin/creatinine ratio on spot urine.

Background and Objectives: The anemia of low-risk myelodysplastic syndromes (MDS), refractory anemia (RA) and RA with ringed sideroblasts (RARS), may respond to treatment with hematopoietic growth factors (GF)); erythropoietin (Epo) +/- granulocyte colony-stimulating factor (G-CSF). The present study was designed to assess whether functional iron deficiency may develop in MDS patients receiving these treatments., Design and Methods: Erythrocyte scattergrams from 34 patients with RA and RARS (untreated, transfused, or GF-treated with partial or complete erythroid response) were analyzed with Bayer-Advia equipment., Results: In untreated RARS, the proportion of hypochromic erythrocytes (Hypo-e, median 6.2%, range 1.1-8%) and hypochromic reticulocytes (Hypo-r, median 45%, range 22-48%), as well as mean corpuscular volume (MCV, median 101 fL) were significantly elevated compared to corresponding values in controls. These values increased further after GF-treatment (median 11%, 57%, and 105 fL, respectively), in spite of improved hemoglobin values and adequate body iron stores. The values observed in untreated RA patients largely fell within the normal range, and there was no significant influence of GF treatment. Notably, the hemoglobin content of reticulocytes (MCHr) did not differ between MDS and controls, and was not influenced by GF treatment., Interpretation and Conclusions: The red cell population in RARS shows morphological abnormalities in terms of varying but overall increased size, and reduced hemoglobin concentration. The proportion of abnormal cells increases after successful pro-erythroid GF treatment, indicating that GF promote erythroblast survival, and maturation into erythrocytes. Hence, the finding of hypochromic red cells should not routinely be interpreted as a marker for Epo-induced functional iron deficiency in MDS.

Both iron deficiency and malaria are common in much of sub-Saharan Africa, and the interaction between these conditions is complex. To investigate the association between nutritional iron status, immunoglobulins, and clinical Plasmodium falciparum malaria, we determined the incidence of malaria in a cohort of children between the ages of 8 months and 8 years who were living on the Kenyan coast. Biochemical iron status and malaria-specific immune responses were determined during 2 cross-sectional surveys. We found that the incidence of clinical malaria was significantly lower among iron-deficient children (incidence-rate ratio [IRR], 0.70; 95% confidence interval [CI], 0.51-0.99; P<.05), that the incidence of malaria was significantly associated with plasma ferritin concentration (IRR for log ferritin concentration, 1.48; 95% CI, 1.01-2.17; P<.05), and that iron status was strongly associated with a range of malaria-specific immunoglobulins. We conclude that iron deficiency was associated with protection from mild clinical malaria in our cohort of children in coastal Kenya and discuss possible mechanisms for this protection.

3H-deoxycytidine, 3H-thymidine and 125I-deoxyuridine were injected intravenously into different groups of chickens and mice, and lymphoid organs and intestine of the animals sampled one hour later. Incorporation of the isotopes into proliferating cells was evaluated after nucleic acid extraction and determination of specific activity of the isotopes in counts per minute per microgram of DNA (cpm/mug DNA). Labelled deoxycytidine was incorporated much better into bursal cells than the other isotopes, indicating that this isotope may preferentially label bursal lymphocytes, or a subpopulation of them.