Determination of the solute removal index for urea by using a partial spent dialysate collection method

In 22 hemodialysis patients, during a dialysis session, the solute removal index (SRI) for urea obtained from the use of a partial spent dialysate collection method was compared with that derived from the use of a total spent dialysate collection technique. The partial spent dialysate collection method was used to harvest a small representative sample of the total spent dialysate. The volumes of spent dialysate collected by the partial and the total spent dialysate collection methods were 1.7 +/- 0.4 L and 129.6 +/- 15.3 L, respectively. The total amount of urea nitrogen removed by dialysis as estimated by the partial spent dialysate collection method was similar to that determined by the total spent dialysate collection approach. As a result, the SRI value for urea obtained by the partial spent dialysate collection method (namely, 63% +/- 8%) correlated very well (r = 0.95, P < 0.001) with that derived by the total spent dialysate collection technique (namely, 62% +/- 8%). Our data suggest that it is feasible to use a simple partial spent dialysate collection method to obtain SRI results in patients treated with hemodialysis.     

An NMR-based metabonomic investigation on effects of milk and meat protein diets given to 8-year-old boys

The objective of the study was to investigate the ability of an NMR-based metabonomic approach, applied to biofluids, to explore and identify overall exogenous and endogenous biochemical effects of a short-time high intake of milk protein or meat protein given to prepubertal children, the aim being to compare relative differences and not an absolute quantification. A total of twenty-four 8-year-old boys were asked to take 53 g protein as milk (n 12) or meat daily (n 12). At baseline and after 7 d, urine and serum samples were collected and high-resolution 1H NMR spectra were acquired on these using a 800 MHz spectrometer. The milk diet reduced the urinary excretion of hippurate, while the meat diet increased the urinary excretion of creatine, histidine and urea. The NMR measurements on serum revealed minor changes in the lipid profile, which most probably should be ascribed to an increase in the content of SCFA in the blood after consumption of the milk diet. The meat diet had no effect on the metabolic profile of serum. The study for the first time demonstrates the capability of proton NMR-based metabonomics to identify the overall biochemical effects of consumption of different animal proteins. The urine metabolite profile is more susceptible to perturbations as a result of short diet interventions than the serum metabolite profile. The milk diet-induced reduction in urinary excretion of hippurate suggests alterations in gut microflora, which may be useful information for further studies elucidating the effects of bioactive components in milk.     

B-cell hybridoma as intraperitoneal tumor model: correlation between tumor growth and monoclonal antibody production.

Murine B-cell hybridoma cells producing an immunoglobulin G1 (K13), specific for human immunoglobulin kappa chains were inoculated intraperitoneally in mice. After intraperitoneal injection of 10(6) K13 hybridoma cells, superficial intraperitoneal implants and ascites developed, resulting in death after 10 +/- 3 days (mean +/- SD). An immunoradiometric assay was developed to measure K13 in murine blood, ascites and culture supernatant. The assay utilized polymer beads coated with human immunoglobulin G. The amount K13 bound to the particles was measured with a 125I-labelled monoclonal rat antibody (LO-MG1-13) specific for mouse IgG1. The assay could be used over a wide working range (2-500 micrograms/l). Kinetic studies suggested that about 10(5) secreting cells were required for detection of K13 in blood. After injection of 10(6) cells, K13 was measurable in blood 1 day later in all animals. Nine of 33 mice injected with 10(5) or less cells survived, and initially showed rising K13 blood levels followed by decreasing blood levels. In conclusion, a close relationship was established between i.p. growth of the hybridoma K13 cell line and the MAb blood levels. The basic concepts of this assay can readily be adopted for other clones with the limitation that pure antigen is needed for solid phase extraction of the MAb from mouse blood.     

Transferrin receptor and B-lymphoblast antigen — their relationship to DNA synthesis,histology and survival in B-cell lymphomas

The reactivity of two monoclonal antibodies indentifying antigens related to B-cell activation, B3/25 (the transferrin receptor) and BB-1 (the B-lymphoblast-1-antigen), was examined on cell suspensions from 75 cases of monoclonal B-cell lymphomas. The expression of B3/25 antigen was correlated to DNA synthesis as measured by spontaneous ³H-thymidine incorporation (p= 0.0003) and histopathologically high-grade malignancy (p= 0.00003). Furthermore, B3/25 expression was associated with survival since the patients with B3/25-negative tumors survived longer than those with B3/25-positive tumors (p= 0.018). B3/25 expression also defined a larger group of patients with shorter survival than did histopathology alone, 28 cases versus 16 cases, respectively. On the other hand, the BB-1 antigen did not reveal an association with DNA synthesis, high-grade malignancy or survival. However, the findings indicated that BB-1 may be related to B-cell maturation/differentiation.     

Cerebellar tuberculoma: a rare disease in an industrialized country

A nine-year-old Somalian boy was treated in Denmark for a posterior fossa tumor, which proved to be a tuberculoma. This disease is virtually unknown in our highly industrialized country, which emphasizes the fact that due to increased international traveling, knowledge of endemic diseases in other parts of the world is necessary. The treatment of tuberculoma and their diagnostic features are reviewed.