Free radical reactions with alpha-tocopherol and N-stearoyl tryptophan methyl ester in micellar solutions

The rate constants have been measured for one-electron oxidation by N3. and Br2-. of N-stearoyl tryptophan methyl ester (STME) and alpha-tocopherol (alpha-T) in micelles of sodium dodecyl sulphate (SDS) or tetradecyl trimethyl ammonium bromide (TTAB). Compared with analogous reactions of tryptophan and Trolox C in aqueous solution, the rate constants for oxidation in micellar solution by N3. are reduced by 30-70%. The micellar charge increased the rate of oxidation of STME by Br2-. in TTAB micelles by almost an order of magnitude, compared with the reaction of Br2-. with tryptophan in aqueous solution. In SDS micelles the rate of oxidation of STME by Br2-. was reduced more than 30-fold. Quenching of fluorescence from STME in micelles by acrylamide confirmed the accessibility of the indole ring to the aqueous solvent. The rate of repair of the neutral STME radical by alpha-T in TTAB micelles was found to be accelerated by a factor of at least 27, compared with the similar reaction between Trolox C and tryptophan radicals in aqueous solution.

Fluorescent substances in uremic and normal serum

We measured the fluorescence, at various excitation (Ex) and emission (Em) wavelengths, of serum ultrafiltrates and fractions of serum resolved by chromatography on Sephadex G15, studying both normal subjects and patients in chronic renal failure requiring hemodialysis. We found hitherto undescribed fluorescence at Ex 380 nm/Em 440 nm and Ex 400 nm/Em 460 nm, the intensity being greatly increased in patients with chronic renal failure in comparison with normal subjects (p less than 0.005). This fluorescence persisted unaltered when serum was filtered through membranes having cutoffs ranging from 10 000 to 500 Da. Each serum fraction resolved by gel chromatography demonstrated a characteristic fluorescence, which was generally much more intense in uremics. The most intense fluorescence (Ex 380 nm/Em 440 nm and Ex 400 nm/Em 460 nm) was emitted in the higher-Mr fractions.

Fluorescent substances in uremic and normal serum

We measured the fluorescence, at various excitation (Ex) and emission (Em) wavelengths, of serum ultrafiltrates and fractions of serum resolved by chromatography on Sephadex G15, studying both normal subjects and patients in chronic renal failure requiring hemodialysis. We found hitherto undescribed fluorescence at Ex 380 nm/Em 440 nm and Ex 400 nm/Em 460 nm, the intensity being greatly increased in patients with chronic renal failure in comparison with normal subjects (p less than 0.005). This fluorescence persisted unaltered when serum was filtered through membranes having cutoffs ranging from 10 000 to 500 Da. Each serum fraction resolved by gel chromatography demonstrated a characteristic fluorescence, which was generally much more intense in uremics. The most intense fluorescence (Ex 380 nm/Em 440 nm and Ex 400 nm/Em 460 nm) was emitted in the higher-Mr fractions.

The morphological features of bovine meshwork cells in vitro and their synthetic activities

The morphological characteristics of 3rd-passage cultured bovine meshwork cells were investigated, as were some of their synthetic activities. Growing meshwork cells had the ultrastructural characteristics of metabolically active cells whereas postconfluent cells formed gap junctions at their lateral borders and were closer in their fine structure to meshwork cells in vivo. The incorporation of 3H proline and 3H glucosamine was significantly greater in growing than postconfluent cultures. The normal bovine outflow system was rich in type I collagen but type V collagen and fibronectin was also evident. The 3rd-passage cells were shown to synthesize type I collagen, type V collagen and fibronectin. However, ultrastructural studies of the extracellular matrix which was produced in vitro demonstrated the presence of small fibrils with no distinctive banding pattern, unlike the larger collagen fibrils with a 640 A banding pattern seen in vivo.

Surgery of pelviureteric obstruction in the first year of life

Twenty-nine out of 108 patients (26%) were under 1 year of age at the time of surgery for congenital pelviureteric obstruction. The clinical features and diagnosis, management, follow-up and results in these patients are reviewed. Clinical presentation was usually with an abdominal mass or urinary infection but an increasing number of cases were diagnosed after maternal ultrasonography had shown hydronephrosis. Ultrasonography, together with renal nuclide scan, were considered to be the most appropriate imaging modalities to define anatomy, determine function and document obstruction. Pyeloplasty was carried out successfully in 28 patients (two bilateral) and one patient had a nephrectomy. Sixteen pyeloplasties were managed by a nephrostomy (with or without a stent), the tubes usually being removed 10-12 days postoperatively. Fourteen pyeloplasties were managed by a wound drain only but one required a secondary nephrostomy although eventual recovery was satisfactory. Renal nuclide scan was found to be the most appropriate follow-up test and the overall results of surgery were satisfactory.

Inhibition of platelet function by uremic middle molecules

To further define the platelet abnormality responsible for uremic bleeding, we studied platelet aggregation with adenosine diphosphate, ristocetin, and collagen in serum fractions obtained by Sephadex G-15 chromatography. We found that uremic patients had considerable inhibition in several peaks of middle molecular range, but the findings were inconsistent and not clearly related to the degree of uremia.

Prolapsed single system ureterocele in a girl

Ureteroceles in childhood usually are associated with ureteral duplication. A 7-year-old girl with a single system ureterocele is described. The patient presented clinically with urinary infection and prolapse of the ureterocele, causing urinary retention.

Urological anomalies in the caudal regression syndrome

Two cases of unusual urological anomalies seen in association with the caudal regression syndrome are reported. One patient had bilateral single ectopic ureters with unilateral renal agenesis and the other a megalo-ureter secondary to a ureteric valve.

Fetal urinary tract abnormalities detected on maternal ultrasound

Twenty-one cases of fetal urinary tract abnormalities were detected on maternal ultrasound in a 5 year period. Six fetuses died and 13 of the 15 surviving cases have had corrective urological surgery, usually during the neonatal period. Maternal ultrasound provides advanced warning of major urinary tract abnormalities in the newborn. Therefore, appropriate investigations and medical management can be instituted early and potentially destructive urological lesions can be corrected as soon as possible. As yet, antenatal intervention does not seem to be warranted as the most common cause of bilateral upper tract dilatation in the surviving cases in this series was primary reflux, and in the cases that died the urinary abnormalities were not salvagable.

Repair of amino acid radicals by a vitamin E analogue

Free radicals derived from one-electron oxidation of the amino acids tryptophan, tyrosine, methionine and histidine have been found to be rapidly (k = 10(7) -10(9) dm3 mol-1 s-1) and efficiently repaired by Trolox C, a vitamin E analogue. The reactions form a relatively stable phenoxyl radical of Trolox C (lambda max = 440 nm; epsilon = 5.4 X 10(3) mol dm-3 cm-1). The radical cation of tryptophan is more rapidly repaired than the neutral tryptophan radical. Repair of tryptophanyl radicals in the enzyme lysozyme has also been observed. The results suggest that a function of alpha-tocopherol in membranes may be the repair of radicals of integral membrane proteins.

Superficial bladder cancer: progression and recurrence

The tumors in 249 patients presenting initially with stages Ta and T1 bladder cancer were analyzed for tumor progression and recurrence. Only transurethral resection and/or fulguration was used before the first recurrence. Patients who received intravesical chemotherapy after the first tumor recurrence were excluded from an analysis of progression. Progression according to stages Ta and T1, and grades I, II and III was 4, 30, 2, 11 and 45 per cent, respectively. All differences were statistically significant. Progression also correlated with nontumor dysplasia and size. High tumor grade, lamina propria invasion, atypia elsewhere in the bladder, positive urinary cytology, tumor multiplicity and large tumors were associated with shorter intervals free of disease.

Urethral ectopic ureter with a ureteric valve

An unusual case of a urethral ectopic ureter in a girl is reported. Only the upper half of the ureter was a megaloureter, the distal half being stenosed. The appearances were consistent with the presence of a ureteric valve.

The effect of beta-galactosides on the protonmotive force and growth of Escherichia coli

The effect of three beta-galactosides on the components membrane potential (delta psi) and pH gradient (delta pH) of protonmotive force and growth of Escherichia coli has been examined. A good correlation between the reduction of the protonmotive force and growth inhibition was observed. Thus some galactosides had little effect on either the protonmotive force or growth while lactose diminished the protonmotive force and caused growth inhibition. This effect of lactose was dependent on the ionic composition of the growth media. In Medium A (77 mM-Na+, 85 mM-K+) lactose diminished delta psi but had no effect on delta pH. Growth inhibition was transient at an external pH 6.0 but complete at pH 7.5. In medium KA (approximately 1 mM-Na+, 162 mM-K+) delta pH was diminished and delta psi was not affected and consequently growth inhibition was complete at pH 6.0. In medium NA (163 mM-Na+, 20 mM-K+) lactose had little effect on delta psi, delta pH or growth. These data support Skulachev's hypothesis of buffering of the protonmotive force by K+ and Na+ gradients.

The use of valinomycin, nigericin and trichlorocarbanilide in control of the protonmotive force in Escherichia coli cells

Valinomycin, nigericin and trichlorocarbanilide were assessed for their ability to control the protonmotive force in Escherichia coli cells. Valinomycin, at high K+ concentrations, was found to decrease the membrane potential delta phi and indirectly to decrease the pH gradient delta pH. Nigericin was found to have two modes of action. At low concentrations (0.05-2 microM) it carried out K+/H+ exchange and decreased delta pH. At higher concentrations (50 microM) it carried out a K+-dependent transfer of H+, decreasing both delta phi and delta pH. In EDTA-treated cells only the latter mode of action was evident, whereas in a mutant sensitive to deoxycholate both types of effect were observed. Trichlorocarbanilide is proposed as an alternative to nigericin for the specific control of delta pH, and it can be used in cells not treated with EDTA.

Application of the pull-through technique of transverse advancement ureteral reimplantation

In the pull-through technique of ureteral reimplantation the ureter is divided at the hiatus and pulled through into the bladder. It is then advanced transversely as described previously for megaloureter but the technique also may be used for routine cases. The technique is particularly suitable for ureteral reimplantation in patients with urethral valves and neurogenic bladder. Pull-through ureteral reimplantation also may be used to reimplant the orthotopic ureter in complete ureteral duplication with ectopic ureterocele or with orthotopic reflux.