Kidney transplantation in Canada, 1981-84.

The Canadian Renal Failure Register was established in 1980. Data have been collected annually for all Canadian patients in whom irreversible kidney failure developed and who required dialysis or transplantation. The authors present actuarial patient and graft survival rates for 1981-84. In 1984, patients with a functioning renal graft accounted for 43.9% of the patients with end-stage renal disease. The number of transplants performed increased from 482 in 1981 to 662 in 1984; however, 1,022 patients undergoing dialysis (25.2%) were on an active waiting list for a transplant at the end of 1984. Greater effort is needed to increase the transplantation rate.     

Sexual differentiation of rat liver carbonic anhydrase III

Using radioimmunoassay, the concentration of carbonic anhydrase III in the livers of adult male rats was found to be approx. 30-times greater than that observed in mature females. Castration of male rats led to a marked reduction in liver carbonic anhydrase III concentrations which could be partially restored to control levels by testosterone replacement. Administration of testosterone to ovariectomised female rats induced about a 5-fold increase in liver carbonic anhydrase III concentration. Immunoprecipitation analysis of the products of liver mRNA translation in vitro with antiserum specific for carbonic anhydrase III showed that hormonal control of the levels of carbonic anhydrase III in liver is mediated by changes in the amount of translatable carbonic anhydrase III mRNA. Marked changes in liver carbonic anhydrase III concentrations were also observed in developing and ageing male rats.     

Chicken lens delta-crystallin gene expression and methylation in several non-lens tissues.

RNA sequences coding for the most abundant chicken lens proteins, delta-crystallin, were detected at very low levels in day old post hatch chick lung, heart, kidney and liver, and in 6 day embryo headless bodies. The pattern of cytosine methylation within the CCGG sequences of the delta-crystallin genes was also examined and shown to vary in several non-lens tissues, from several stages of development. Embryonic neural retina, which expresses a higher level of delta-crystallin RNA than the above tissues, is no less methylated in the sites studied than the tissues which have no association with the eye, and is actually more heavily methylated than the kidney. Thus no obvious correlation was found between undermethylation and gene expression.     

Some metabolites of 1-bromobutane in the rabbit and the rat

1. Rabbits and rats dosed with 1-bromobutane excrete in urine, in addition to butylmercapturic acid, (2-hydroxybutyl)mercapturic acid, (3-hydroxybutyl)mercapturic acid and 3-(butylthio)lactic acid. 2. Although both species excrete both the hydroxybutylmercapturic acids, only traces of the 2-isomer are excreted by the rabbit. The 3-isomer has been isolated from rabbit urine as the dicyclohexylammonium salt. 3. 3-(Butylthio)lactic acid is formed more readily in the rabbit; only traces are excreted by the rat. 4. Traces of the sulphoxide of butylmercapturic acid have been found in rat urine but not in rabbit urine. 5. In the rabbit about 14% and in the rat about 22% of the dose of 1-bromobutane is excreted in the form of the hydroxymercapturic acids. 6. Slices of rat liver incubated with S-butylcysteine or butylmercapturic acid form both (2-hydroxybutyl)mercapturic acid and (3-hydroxybutyl)mercapturic acid, but only the 3-hydroxy acid is formed by slices of rabbit liver. 7. S-Butylglutathione, S-butylcysteinylglycine and S-butylcysteine are excreted in bile by rats dosed with 1-bromobutane. 8. Rabbits and rats dosed with 1,2-epoxybutane excrete (2-hydroxybutyl)mercapturic acid to the extent of about 4% and 11% of the dose respectively. 9. The following have been synthesized: N-acetyl-S-(2-hydroxybutyl)-l-cysteine [(2-hydroxybutyl)mercapturic acid] and N-acetyl-S-(3-hydroxybutyl)-l-cysteine [(3-hydroxybutyl)mercapturic acid] isolated as dicyclohexylammonium salts, N-toluene-p-sulphonyl-S-(2-hydroxybutyl)-l-cysteine, S-butylglutathione and N-acetyl-S-butylcysteinyl-glycine ethyl ester.     

Microporosity of the substratum regulates differentiation of MDCK cells in vitro

Summary We have analyzed the ability of the physical substratum to modulate both the ultrastructural and protein synthetic characteristics of the Madin-Darby canine kidney (MDCK) renal cell line. When MDCK cells were seeded on Millipore Millicell CM microporous membrane cell culture inserts they demonstrated a more columnar organization with an increase in cell density sixfold greater than the same cells seeded on conventional plastic substrata. After 1 wk postseeding on the microporous membrane a partial basal lamina was noted, with a contiguous basement membrane being apparent after 2 wk. One-dimensional sodium dodecyl sulfate gel electrophoresis was used to analyze detergent-solubilized proteins from MDCK cells maintained on plastic substrata vs. microporous membranes. When proteins were pulse-labeled with [³⁵S]methionine, a 55 kDa protein was evident in the cytosolic extract of cells grown on collagen, laminin, and nontreated plastic substrata; but this labeled protein was not evident in similar extracts from cells grown on collagen and laminin-coated microporous membranes. To test if the polarized, basement-membrane secreting phenotype of the MDCK cells could be generated on a microporous membrane without pretreatment with any extracellular matrix (ECM) components, cells were seeded on the Millipore Millicell HA (cellulosic) microporous membrane. This type of substrata does not need a coating of ECM components for cell attachment. A partial basement membrane was formed below cells where the basal surface of the cell was planar, but not in areas where the cell formed large cytoplasmic extensions into the filter. This led us to the conclusion that the microporous nature of the substrata can dictate both ultrastructural and protein synthetic activities of MDCK cells. Furthermore, we suggest that both the planar nature of the basal surface and the microporosity of the substrate are corequisites for the deposition of the basement membrane.     

Receptor inactivation by dye-neuropeptide conjugates. 3. Comparative binding of dye-neuropeptide conjugates to FMRFamide receptors of Helix aspersa and Loligo pealei

Three neuropeptide analogues of FMRFamide (FMRFa) were covalently attached to a tethered derivative of methylene blue to form dye-neuropeptide conjugates. The comparative binding of the latter to FMRFa receptors was subsequently examined in both Helix aspersa (circumesophageal ganglia) and squid (optic lobe membrane). In Helix, the FMRFa analogue CFMRFamide (CFMRFa) inhibited the specific binding of the FMRFa ligand [¹²⁵I]daYFnLRFa in a dose-dependent manner. Az-CFMRFa, one of the dye-neuropeptide conjugates, also dose-dependently inhibited the specific binding of [¹²⁵I]daYFnLRFa. Moreover, their potencies equaled or exceeded that of FMRFamide. In squid, the binding of CFMRFa and FMRFa was similar. However, the dye-neuropeptide conjugate (IC₅₀ of 14 nM) was about 44-fold less potent than FMRFa. The conjugates were synthesized as part of a study seeking to target and inactivate preselected receptors with heretofore unattainable selectivity and permanence.