Nucleation and aggregation of calcium oxalate in whole urine; spectrophotometric sedimentation analysis: a new approach to study the aggregation of calcium oxalate dihydrate.

Spectrophotometric and scanning electron microscopic (SEM) studies of oxalate-induced crystallization have been performed in whole urine with and without continuous magnetic stirring and before and after millipore filtration of urine. With continuous stirring, preferential nucleation was observed and this followed second order kinetics. Important crystal aggregation only occurred after an oxalate load above 1 mmol/l and without stirring. Under these conditions and at an ionic calcium concentration of 2 mmol/l, single crystals and aggregates of calcium oxalate dihydrate and monohydrate of well defined sizes were produced. Single dehydrates, their aggregates and the other particles could be distinguished by their significantly different sedimentation rates. From sedimentation curves an aggregation ratio for calcium oxalate dihydrate (aggregated/total dihydrate particles) was extrapolated. Millipore filtration removing important urinary macromolecules increased this aggregation ratio as well as the size of the aggregates on SEM pictures.

Association between immunity and prognostic factors in early stage breast cancer patients before adjuvant treatment.

OBJECTIVE: The association of known prognostic factors with immune cell counts and beta2-microglobulin and soluble IL-2 receptor (sIL-2r) serum levels as markers of activation of the immune system was investigated in breast cancer. METHODS: Two hundred thirty five operated stage I and II breast cancer patients to receive adjuvant treatment in IBSCG trials were assessed in a cross-sectional study immediately before the first treatment. Leukocytes, lymphocytes and lymphocyte subset counts, beta2-microglobulin and sIL-2r serum levels were assessed as immunological parameters. Prognostic factors were tumor load, receptor status, patient characteristics, and contextual factors of the immune assessment (such as time of the day, time since surgery, type of surgery, concomitant medication, co-morbidity). RESULTS: In an operated early stage breast cancer patient population, tumor load was not associated with immune cell counts, beta2-microglobulin, or sIL-2r before adjuvant treatment. There was a pattern of association of prognostically favorable factors such as estrogen receptor (ER) positive tumor and older age with higher NK cell counts or with beta2-microglobulin or sIL-2r. In addition, immune cell counts and the markers of activation of the immune system were affected by several contextual factors, such as diurnal variability, time since surgery, type of surgery, and the intake of concomitant medication. CONCLUSIONS: The association of NK cell counts and beta2-microglobulin or sIL-2r serum levels with prognostically favorable factors such as ER positive tumor and older age supports the assumption that the immune system plays a role in the course of early breast cancer. The exact nature of this role requires further study.

Interaction of tamoxifen with concurrent cytotoxic adjuvant treatment affects lymphocytes and lymphocyte subsets counts in breast cancer patients.

The effects and interaction of endocrine and cytotoxic adjuvant treatment on measures of cellular immunity were assessed in 41 stage I-II breast cancer patients from International Breast Cancer Study Group trials. Counts of lymphocytes and lymphocyte subsets [(T, T4, T8, B, natural killer (NK) and activated T (AT) cells] were assessed by flow cytometry immediately before adjuvant therapy at baseline and on day 1 of the 3rd cycle. Twenty-two patients received cyclophosphamide, methotrexate and 5-fluorouracil (CMF), 7 CMF and tamoxifen (TAM), and 12 TAM alone. On day 1 of the 3rd cycle the counts of total lymphocytes (P = 0.003) and all lymphocyte subsets (P<0.05) except AT cells were significantly lower than baseline in the CMF treatment group. There was no significant change in the CMF+TAM or in the TAM treatment group. The combination of CMF and TAM resulted in less pronounced decrease in lymphocyte and subset counts from baseline to day 1 of the 3rd cycle. It seems possible that there is an interaction between TAM with CMF that affects lymphocyte and lymphocyte subset counts during cytotoxic treatment.

Measurement of metastability, growth and aggregation of calcium oxalate in native urine. A new approach for clinical and experimental stone research.

Nucleation, growth and aggregation are thought to be the most important crystallization processes in stone formation. Since crystallization properties change with urinary dilution, centrifugation and filtration, crystallization should always be studied in freshly voided and not pretreated urine. Recently we developed an automated method where calcium oxalate crystallization is induced in native urine by an exogenous oxalate load and nucleation and growth are monitored by an ion-selective calcium electrode. The method has now been supplemented with the spectrophotometric measurement of crystal aggregation. Repeated experiments in the same urine with different oxalate loads enable the determination of the critical oxalate additionable to induce crystallization (metastable limit) and the calculation of an oxalate load-independent growth rate constant. Preliminary results obtained in the native urine of healthy controls showed an extremely high limit of metastability and a complete absence of crystal aggregation. These findings may explain why, despite frequent urinary calcium oxalate supersaturation, healthy people do not form stones.

Automated and computer-controlled method for the measurement of the crystallization of calcium oxalate monohydrate in urine.

Monitoring of crystallization of calcium salts with ion-selective electrodes has turned out to be a very sensitive method. The difficulties of handling these electrodes in native whole urine and other biological fluids have been eliminated by new calcium analyzers, which clean and calibrate the electrodes after each measurement. To study crystallization kinetics, repeated calcium ion measurements have to be performed at regular intervals. For this purpose we have developed a special sampler and software. The sampler brings a thermostat-controlled crystallization chamber to the analyzer at preselected intervals. The computer directs and coordinates the sampler and the analyzer, stores the received results and prints out growth curves. Furthermore it calculates the half-time (h) and the maximum decrease of ionic calcium at infinite incubation time (delta Ca2+ infinity). Both values are shown to characterize the growth of calcium oxalate monohydrate in urine. Results are obtained within 40 min.

Utilization of galactose in cultured brain cells of neonatal mice.

Metabolism of galactose was examined in dissociated brain cells from neonatal mice after 10-13 days in culture. Consumption of galactose at levels up to 26 mM was much less than consumption of glucose at corresponding concentrations. Lactate was consumed from the media at all galactose levels, in contrast to experiments with glucose in which lactate was formed and released into the media. Generation of CO2 from 4 mM glucose was 9-fold greater than from an equimolar level of galactose. Relatively low concentrations of glucose could reduce uptake of galactose, whereas galactose at levels up to 11.6 mM failed to inhibit consumption of glucose or formation of lactate. In glucose-deficient states, galactose supplementation of the media led to a marked increase in sulfatide synthesis by oligodendrocytes in the culture with a maximum effect at 2.3 mM. Under these conditions, [1-14C]galactose was incorporated directly into the carbohydrate portion of sulfatide, although most of the label was found in phospholipids and in the nonlipid fraction of the cellular homogenate. These data suggest that galactose is poorly metabolized by brain cells, but does not exhibit toxic effects.

Vesicular transport of sulfatide in the myelinating mouse brain. Functional association with lysosomes?

Sulfatide synthesis and its subcellular distribution kinetics was followed in the myelinating brain of 17-day-old mice. Pulse-labeling-chasing conditions were achieved by an intraperitoneal injection of (35S)sulfate followed 2 h later by a second injection of a high dose of unlabeled sulfate. At 1, 2, 3, 4, and 6 h after the (35S)sulfate injection, the brains were removed, homogenized, and subcellular fractions were obtained by differential and discontinuous sucrose gradient centrifugation (Eichberg, J., Whittaker, V. P., and Dawson, R. M. (1964) Biochem. J. 92, 91-100). The microsomal membranes were further subfractionated (Siegrist, H. P., Burkart, T., Wiesmann, U. N., Herschkowitz, N. N., and Spycher, M. A. (1979) J. Neurochem. 33, 497-504) into light myelin, plasma membranes, Golgi vesicles, endoplasmic reticulum membranes, and heavy vesicles associated with acid hydrolase activities. The [35S]sulfatide-labeling kinetics was measured in all subcellular fractions. The results indicate that sulfatides are synthesized in the Golgi-endoplasmic reticulum complex and transferred in vesicles at least partially associated with lysosomes to the myelin membranes. The association of sulfatides with lysosomes could explain the existence of the previously described labile pool of newly synthesized sulfatides (Burkart, T., Hofmann, K., Siegrist, H. P., Herschkowitz, N. N., and Wiesmann, U. N. (1981) Dev. Biol. 83, 42-48) and also could be a form of vesicular transport to the myelin.

Abnormal growth kinetics and 5'-nucleotidase activities in cultured skin fibroblasts from patients with Duchenne muscular dystrophy.

The experiments reported herein compare growth kinetics and biochemical properties of cultured skin fibroblasts from patients with Duchenne muscular dystrophy (DMD) and matched normal controls. On day 7 after plating (6000 cells/cm2) cell number and DNA per dish are significantly reduced (P less than 0.0001) in the cultures from DMD patients (n = 14), compared to those from controls (n = 10). Moreover DMD cells contain less lipids and proteins per dish but more per cell than normal fibroblasts (not significant). Variations of media (McCoy's medium instead of Eagle's minimum essential medium) resulted in the same differences between DMD and control cells. Cell kinetic experiments (plating density: 2000 cells/cm2) show increased doubling times of DMD fibroblasts (P less than 0.001; nDMD = 5; ncontrols = 4) whereas plating efficiency is equal for both DMD and controls. On day 7 activity of the membrane bound enzyme 5'-nucleotidase either per mg protein or per microgram DNA is significantly elevated in cells from DMD patients (P less than 0.0005; nDMD = 8; ncontrols = 9) independent of cell density. Thus all findings in cultured DMD fibroblasts: increased doubling time, tendency to more voluminous cells, and elevated 5'-nucleotidase activity per cell suggest, that the DMD cells behave similar to prematurely aging cells. Until now we were not able to check whether any alterations of the plasma membrane are inducing early senescence or, reversely, premature aging is the cause of the postulated membrane alterations. If these findings were to be confirmed in cultured amniotic cells from DMD fetuses, thay could serve as a potential prenatal diagnosis of the disease.

Relative changes in the amount of galactocerebroside during development as observed in mouse brain cell cultures.

Relative changes in the amount of galactocerebroside (GC) during development were measured in mouse brain cell cultures at different stages of development. For this purpose we used an 125I-labelled protein A indirect assay modified in the respect that the total amount of cellular proteins was evaluated before counting the radioactivity. The amount of GC greatly increased between the 10th and the 14th day of culture, then a steady state was reached between the 14th and the 20th day of culture. This change correlates well with the dynamics of the number of oligodendrocytes we observed earlier. These data suggests that the increase of the GC amount in culture during development corresponds to the increase in the number of GC-positive oligodendrocytes rather than to the increase in the number of GC molecules per cell.

Expression of antigenic markers during the development of oligodendrocytes in mouse brain cell cultures.

The expression of myelin basic protein (MBP) and galactocerebroside (GC), two antigenic markers for oligodendrocytes, was checked on 7-, 14-, 21- and 28-day-old dissociated mouse brain cell cultures (BCC) by using the indirect immunofluorescence method with double staining. The number of GC positive cells increased between the 7th and the 14th day of culture before a steady state was reached. In contrast to this, the MBP-positive cells appeared only on the 14th day of culture, and their number increased with the age of the culture. In double staining, the serum produced against isolated oligodendrocytes shows the same picture as the anti-GC serum, while only a part of GC-positive cells showed also the presence of MBP. Our data suggest that the GC appears very early on the membrane of the oligodendrocytes during development while cells exhibiting both GC and MBP probably represent a more differentiated oligodendrocyte population.

Net sulfatide synthesis, galactosylceramide sulfotransferase and arylsulfatase A activity in the developing cerebrum and cerebellum of normal mice and myelin-deficient jimpy mice.

Net sulfatide synthesis, galactosylceramide sulfotransferase (EC 2.8.2.11) and arylsulfatase A (EC 3.1.6.1) activities were measured in two brain regions, cerebrum and cerebellum, of normal and jimpy mice during postnatal development. In normally myelinating mice, two phases of increasing rates of net sulfatide synthesis were observed, the first coinciding with oligodendrocyte proliferation and the second with myelination. Net sulfatide synthesis was quantitatively higher in the cerebellum than in the cerebrum. In both brain regions, the developmental patterns of net sulfatide synthesis were related to the activity patterns of both galactosylceramide sulfotransferase and arylsulfatase A. In jimpy mice, a neurological mutant showing hypomyelination in brain, the first phase of net sulfatide synthesis was preserved in both brain regions and galactosylceramide sulfotransferase and arylsulfatase A activities were normal up to 12 days. However, during the phase in which myelination occurred in controls, the net sulfatide synthesis in both brain regions of jimpy mice was zero or even negative. The sulfatide deficit was larger in the cerebellum than in the cerebrum. In both mutant brain parts, galactosylceramide sulfotransferase activity increased up to 12 days showing about 50% of the maximal activities observed in normal brain regions. Thereafter up to 15 days, enzyme activity decreased to about 25% of that of controls and remained low in both brain regions. The developmental patterns and the activities of arylsulfatase A were, however, normal in the cerebrum and cerebellum of jimpy mice. These results suggest that the enzyme activities and the developmental patterns of galactosylceramide sulfotransferase and arylsulfatase A as measured in vitro reflect to a high degree their functional activity in vivo. Furthermore, sulfatide degradation by arylsulfatase A seems to be important in regulating net sulfatide synthesis during normal and impaired myelination.

Immunological properties of bulk isolated mouse oligodendrocytes.

Mouse oligodendrocytes were isolated in bulk. These cells were 95% galactocerebroside-positive. Rabbit anti-mouse oligodendrocyte antisera reacted in radioimmunoassay and in indirect immunofluorescence with mouse oligodendrocytes in suspension or in culture. The activity of the sera was not blocked by adsorption with galactocerebroside or by preincubation of cells with anti-galactocerebroside serum, although it cross-reacted with galactocerebroside in a serological test. The staining was not impaired by the pretreatment of cells with trypsin, neuraminidase or acetone, nor by adsorption of serum with myelin basis protein.

Synthesis of lipids in mouse brain cell cultures during development.

Several metabolic activities in dissociated cultures of newborn mouse brain were compared to the situation in vivo. The developmental activity pattern of cerebroside-sulfotransferase, cyclic nucleotide phosphohydrolase, and beta-hydroxy-beta-methyl glutaryl-coenzyme A-reductase and the synthesis and deposition of sulfatide and cholesterol in culture were estimated. The enzyme activity patterns in vivo and in culture are the same. Since the cultures show very little myelin formation, the parallel increase of enzyme activities necessary for myelination in vivo and in culture suggest the existence of intrinsic factors regulating the biochemical differentiation. In addition, the formation of the products, determined in culture, follows the patterns of the enzyme activities. Dissociated brain cell cultures are therefore a valid model for the study of biochemical parameters related to the synthesis of brain lipids during development.

Abnormal metabolism of 35SO4-sulfatide in jimpy brains expressed in brain organotypic cultures.

Cerebroside-sulfotransferase (CST), creatine-phosphokinase (CPK), and 3-hydroxy-3-methylglutaroyl CoA (HMG CoA) reductase activity, protein, and DNA content were measured in an easy-to-perform organotypic culture system of newborn normal and jimpy brains. The defective sulfatide synthesis which has been shown in vivo in jimpy brains could also be demonstrated in organ cultures of jimpy mice in the form of lowered CST activity in the homogenate as well as reduced 35SO4 incorporation into 35SO4-sulfatide. HMG CoA reductase was reduced to 60% of that found in 16-day-old normal cultures, similar to the findings in vivo. DNA of jimpy cultures was significantly lower than that in normal cultures, suggesting the possibility of an arrest in the differentiation or increased cellular death of presumptive oligodendrocytes, as was found in vivo. Organ cultures of jimpy mouse brain can serve as an appropriate model for further study of the primary defect in this animal mutant.

Theophylline reduces the activity of cerebroside-sulfotransferase, a key enzyme in myelination, in cell cultures from newborn mouse brain.

Theophylline, a drug used in neonatology for the treatment of apnea, affects cholesterol synthesis if administered in concentrations of 10(-4) M (a concentration found in serum of treated patients) for 24 hr to dissociated brain cell cultures. The rate-limiting enzyme of cholesterol synthesis, beta-hydroxy-beta-methylglutaryl-coenzyme A reductase (EC 1.1.1.34), is lowered to 45% 48 hr after removal of theophylline. At the same time, cholesterol content of the cells is lowered to 73%. Inasmuch as the phospholipid content of the cells remains stable, the treatment changes the cholesterol phospholipid ratio. Concomitant to this effect, the activity of cerebroside-sulfotransferase (EC 2.8.2.11) is lowered to 60% of control values. We postulate that these two effects are linked to each other by means of modulation of the cerebroside-sulfotransferase activity by membrane lipids.

Progressive somatofugal activation of cerebroside sulfotransferase in the developing chick optic fibers.

A myelination parameter of the chick optic pathway has been investigated: the activity of cerebroside sulfotransferase. Evidence is presented for a somatofugal progression of the enzyme activity peak along the optic nerve, chiasm, optic tract, tectum anterior, and tectum posterior. The enzyme activity appears on the fifteenth embryonic day and reaches a maximum in the nerve two days before hatching. One day after hatching, the peak is found in the chiasm, and three days after that in the optic tract. The peak is found in the tectum anterior on the tenth day. The results suggest a somatofugal progression of myelination.