Considerations for utilizing medullary sponge kidney allografts in pediatric patients

BACKGROUND

Medullary sponge kidney (MSK) disease predisposes patients to recurrent nephrolithiasis, which affects one in every 5000 people in the United States.

METHODS

We report a rare case of a pediatric recipient of a living donor MSK transplant and discuss considerations when discussing risks and benefits of accepting MSK allografts for this population.

RESULTS

The recipient was admitted due to concerns for nephrolithiasis, hydronephrosis, and urinary tract infection at 1-month post-transplant. The hydronephrosis was resolved by surgical removal of an encrusted ureteral stent; this was followed by supplementation with oral medications to prevent future episodes of nephrolithiasis. The recipient did not have any further episodes after this as seen at a 1-year follow-up. The donor has remained well through this period.

CONCLUSIONS

With increasing organ shortages, the use of variety of donors may need to be considered to enlarge the organ pool.

Pleurotus Eous mushroom lectin (PEL) with mixed carbohydrate inhibition and antiproliferative activity on tumor cell lines

A novel Pleurotus eous mushroom lectin (PEL) having mixed binding specificity was purified to homogeneity from the fruitbodies of P. eous. The lectin showed monomer weight of 16 kDa and was a glycoprotein having a 9% neutral sugar content. The antiproliferative activity of PEL was tested on four human tumor cell lines. A 50% inhibition of proliferation was demonstrated in MCF-7, K562 and Hep2 cell lines at the lowest concentration (2 microg/ml) of lectin tested. SK-N-MC cell line showed 50% inhibition at 50 microg/ml of PEL. The inhibitory activity of PEL was not associated with toxicity to cell lines.

Characterisation of agglutination properties of myelin basic protein

Myelin basic protein (MBP) from one month old rat brain was purified by CM-52 cellulose chromatography and heparin sepharose chromatography. It's lectin properties were studied and conditions for optimum agglutination were observed. MBP behaved likea heparin binding lectin. Carbohydrade binding specificity studies showed that on molar basis MBP was feebly inhibited by lactose and strongly inhibited by heparin. Inhibition due to heparin was not due to electrostatic forces as evidenced by no inhibition due to other glycosaminoglycans. Argine and lysine residues were involved in the agglutination activity of MBP.

Novel 29 kDa heparin-binding lectin from human foetal brain

Heparin inhibitable lectins are physiologically important because of their interactions with extracellular matrix and with other cell surface glycoconjugates. However, due to the unstable nature of these animal lectins, it becomes necessary to purify them in the shortest possible time. In the present study, a chromatographic procedure was developed to separate heparin inhibitable lectin activity. Lectin activities from human foetal brain were separated on a Q-Sepharose column employing different equilibration conditions. When proteins were loaded on to a phosphate-buffered saline (PBS) equilibrated column and eluted with salt gradient, only one lectin peak was obtained. However, when proteins were loaded on to a hypotonic equilibrated column and eluted with a salt gradient, four lectin peaks were obtained. The lectin peak obtained from the PBS equilibrated column was characterized as heparin inhibitable lectin. On SDS-PAGE analysis, it gave a single band of 29 kDa. For optimum lectin activity, a pH of around 7.0 was required. Lectin activity was stimulated by Mn++; amino acid composition was different from other known lectins. The lectin was particularly rich in acidic amino acids. Regional distribution of 29 kDa lectin in different foetal brain regions gave the highest content in the cerebral cortex, showing a caudoroastral distribution. Determination of the subcellular distribution of the lectin in the foetal cerebral cortex gave the highest value with a mitochondrial fraction.

Lactose- and heparin-inhibitable agglutinin from human fetal brain

An agglutinin activity which was sensitive to lactose and heparin was estimated during prenatal brain development. The agglutinin showed higher specific activities in cerebral cortex and midbrain. There was an increase in lectin specific activity in all the brain regions with development. In addition to brain, other fetal organs also showed the presence of developmentally regulated agglutinin. Cerebral cortical agglutinin was purified by Sepharose CL-6B gel filtration and asialofetuin- and heparin-Sepharose affinity chromatography. Purified agglutinin was strongly inhibited by lactose, asialofetuin, and heparin. It showed no requirement for divalent cations and was maximally active at pH 8.0. Electrophoretic characterization showed the aggregate nature of the agglutinin, and sodium dodecyl sulfate-polyacrylamide gel electrophoresis gave subunit molecular weights of 58,000, 45,000, and 24,000.

Cathepsin D and 2',3'-cyclic nucleotide 3'-phosphohydrolase in developing human foetal brain

Three peaks of proteinases were observed with hemoglobin, bovine serum albumin and casein as substrates at the pH of 3.5, 6.5 and 8.5, in prenatal human cerebral cortex. Cathepsin D (EC 3.4.23.5) was the most prominent, with hemoglobin as the preferred substrate. The enzyme was partially purified by Concanavalin A - Sepharose affinity chromatography and the nature of the active site was assessed with proteinase inhibitors. Inhibitor studies showed that similar to pepstatin A, benzethonium chloride was also strongly inhibitory to the enzyme. The distribution of cathepsin D, a neuronal marker, and 2',3'-cyclic nucleotide 3'-phosphohydrolase (EC 3.1.4.37), a oligodendroglial marker in foetal brain regions with increasing gestation revealed that neurogenesis and gliogenesis occur concomitantly from earlier periods of gestation. Glial marker acquisition was particularly high in medulla and in spinal cord between 20 and 25 weeks of gestation.

Succinate dehydrogenase, monoamine oxidase and glutamine synthetase in developing human foetal brain regions

In human foetal brain ontogeny the cerebral activity of succinate oxidoreductase (EC 1.3.99.1), i.e. succinate dehydrogenase (SDH), is higher than the cerebellar activity. With rise in foetal body weight the activity in all the brain regions gradually declines. SDH in all the brain regions shows two high-activity periods, one at 20-35 g and another at 110-220 g body weight. The enzyme exhibits a craniocaudal pattern of development. At all times of gestation, L-glutamate:ammonia ligase (EC 6.3.1.2), i.e. glutamine synthetase, activity in the spinal cord and medulla is higher than in the other three regions. At 190 g body weight glutamine synthetase shows an activity peak in all brain regions. Monoamine:oxygen oxidoreductase (EC 1.4.3.4). i.e. monoamine oxidase (MAO), is present much before the onset of electrical activity. It develops caudocranially and exhibits a biphasic pattern of development in all the regions. It increases considerably in the medulla and the spinal core towards late gestational periods.