Fenoprofen nephropathy: lipoid nephrosis and interstitial nephritis. A possible T-lymphocyte disorder

Five patients are presented, each of whom had an acute idiosyncratic reaction to fenoprofen calcium (Nalfon) characterized by acute renal failure and marked proteinuria. Renal pathology was similar in all patients. Light microscopy revealed marked lymphocytic inflammatory infiltrates and normal glomeruli. Immunofluorescent staining was minimal or absent. Electron microscopy showed fusion of podocytes in otherwise normal glomeruli. Two patients were studied using T-cell and B-cell specific fluorescent staining, which revealed that the interstitial infiltrates were composed exclusively of T-lymphocytes. This finding is considered in relation to prior experimental and theoretic work. It is suggested that the various clinical and pathologic findings in fenoprofen nephropathy are all manifestations of a disordered cell-mediated immunity.

Bumetanide: potent new "loop" diuretic

Bumetanide, a pharmacologically new diuretic, was evaluated in 27 subjects. Its onset of action was within 30 minutes with a peak at 90 minutes and a total duration of action of about 270 minutes. In a controlled study in oedematous patients it was equipotent with frusemide at one-fortieth the molar dosage and did not differ from frusemide with regard to its pattern of electrolyte excretion. On continuous oral administration for eight days it produced effective diuresis with minimal alteration in biochemical and haematological status. The only adverse effect was gastric discomfort in one patient.

Effects of nonsteroidal antiinflammatory drugs on renal function in sickle cell anemia

Renal hemodynamics and solute and water handling were evaluated in 19 sickle cell patients and 8 matched normal subjects during water diuresis, before and after acute oral administration of a nonsteroidal antiinflammatory drug (NSAID). Baseline GFR and RPF were higher in the patients compared to the normals. In contrast to normals, indomethacin and sulindac induced a 16% and 14% decrease in GFR, respectively. Indomethacin resulted in a slight increase in UOsm in normals, but a substantially greater rise in the patients. Following indomethacin a greater fall in FENa, fractional solute delivery to the diluting segment of the nephron [(CH2O + CNa + K)/GFR], fractional solute reabsorption in the diluting segment [CH2O/GFR] and the fraction of distally delivered solute reabsorbed [CH2O/(CH2O + CNa + K)] was observed in the sickle cell patients than in the normal subjects. A similar trend, but of significantly lesser magnitude than that induced by indomethacin, was observed following sulindac in the sickle cell patient. The data imply that the supranormal GFR observed in the sickle cell patients was prostaglandin-mediated. The effects of NSAID's on renal solute and water handling in the sickle cell patients are compatible with a prostaglandin-dependent decreased salt reabsorption in the medullary thick ascending limb of Henle, together with a hyperfunctioning proximal tubule. The data also imply an additional indomethacin-sensitive antinatriuretic effect in the diluting segment in these patients. Moreover, the results suggest that in sickle cell anemia sulindac may not have a "renal sparing" advantage over other NSAID's.

Acid-base induced alterations in glutamine metabolism and ureogenesis in perfused muscle and liver of the rat

The effects of altered acid-base balance on the production of urea and the metabolism of glutamine were investigated in the isolated perfused liver and hindquarter of the rat. In the isolated perfused rat liver, lowering of perfusate pH without altering bicarbonate concentration significantly reduced urea production and increased net glutamine synthesis, although the converse did not obtain. In the isolated perfused rat hindquarter when perfusate pH and bicarbonate were simultaneously reduced glutamine synthesis was significantly increased. The combined hepatic and muscle increase in glutamine synthesis accounted for 89% of the decrease in hepatic urea synthesis under these experimental conditions. These changes in nitrogen metabolism are interpreted in terms of adaptations which offset the initial alterations in hydrogen ion homeostasis.

T and B lymphocyte subsets in fenoprofen nephropathy

Renal failure due to combined acute interstitial nephritis and minimal-change glomerulopathy is reported in two patients after fenoprofen therapy. In the interstitial infiltrates, T lymphocytes predominated over B lymphocytes in a ratio of four to one. The majority of B lymphocytes present were IgE-bearing cells. Among the T cells, the ratio of cytotoxic/suppressor cells to helper-inducer cells was three to one. Repeated renal biopsy in one patient after steroid-induced clinical remission demonstrated resolution of the inflammatory infiltrate and restoration of normal glomerular foot processes. The theoretic and practical implications of these findings are discussed.

Measuring self-efficacy in gambling: the Gambling Refusal Self-Efficacy Questionnaire

This paper reports on the development and psychometric properties of a Gambling Refusal Self-Efficacy Questionnaire (GRSEQ). Two hundred and ninety-seven gamblers from both normal and clinical populations completed an initial set of 31-items of which 26 were selected for inclusion in the final version of the GRSEQ. A series of factor analyses showed four clear factors accounting for 84% of the variance. These factors can be summarised as situations and thoughts associated with gambling, the influence of drugs on gambling, positive emotions associated with gambling and negative emotions associated with gambling. The GRSEQ total score and factors scores showed high internal consistency (Cronbach's alpha ranging from 0.92 to 0.98). Participants experiencing problems with gambling scored significantly lower on the GRSEQ, and discriminant analyses showed that the scale is able to correctly classify the non-problem (i.e., community and student samples) and problem gamblers (i.e., clinical sample). Furthermore, the GRSEQ showed significant negative relationships with other gambling-related variables (gambling urge and gambling-related cognitions) and negative mood states (depression, anxiety and stress) and was shown to be sensitive to change in treatment of pathological gambling. The results suggest that the GRSEQ is a useful measure of gambling refusal self-efficacy that is suitable for assessment of gamblers from both normal and clinical populations.

Management of chronic peritoneal catheter malfunction

This paper presents a modification of Tenckhoff's insertion procedure for chronic peritoneal dialysis catheters and reviews the results of a technique of management of catheter malfunction by manipulation which obviates the need for catheter replacement. 43 catheters in 33 patients were observed for no less than 1 year. Catheters which malfunctioned within 3 weeks benefited only marginally from manipulation. In those catheters which functioned for more than 3 weeks, manipulation extended mean survival time by 103% (8.5-17.3 months) and overall survival did not differ statistically from catheters not requiring manipulation. The technique is safe and simple and contributes to the effective management of patients undergoing chronic peritoneal dialysis.

Loss of Ikappa B-beta is associated with prolonged NF-kappa B activity in human glial cells

Nuclear factor-kappaB (NF-kappaB) is an inducible transcription factor central in the regulation of expression of a wide variety of genes and synthesis of several proteins involved in the generation of the immune response and inflammatory processes. In resting cells, NF-kappaB is maintained in an inactive state through cytoplasmic retention by IkappaB inhibitors. Stimulation of cells with a wide variety of inducers results in proteolytic degradation of these IkappaB proteins, leading to activation of NF-kappaB. The present study shows that interleukin-1 (IL-1) causes persistent activation of NF-kappaB in glial cells. Stimulation with IL-1 also causes rapid but transient degradation of IkappaB-alpha and IkappaB-epsilon. However, NF-kappaB remains active even after these IkappaB isoforms have returned to control levels. In contrast, the IkappaB-beta isoform fails to reappear following its initial degradation by IL-1, coincident with sustained activation of NF-kappaB. In addition, in vivo overexpression of the various IkappaB isoforms revealed that IkappaB-beta is the only isoform that has the ability to inhibit IL-1-induced NF-kappaB-driven transcription. The findings also suggest that the inability of IkappaB-alpha and IkappaB-epsilon to modulate NF-kappaB activity is due to their modification in vivo. These findings indicate that IkappaB-beta is the key regulator of the activity of NF-kappaB in human glial cells.

Effect of megadoses of ascorbic acid on serum and urinary oxalate

Serum and urinary oxalate was determined in 9 normal subjects, ingesting 8 g of ascorbic acid daily. Serum oxalate levels increased to 310% of control values during supplementation. Plasma ascrobate levels reached a mean value of 3.6 mg% far exceeding the previously reported plateau level of 1.8 mg%. Urinary oxalate gradually increased during ascorbate intake and 7 days post cessation of ascorbate, rose unexpectedly for all subjects into the hyperoxaluric range.

Quantifying Argonaute 2 (Ago2) expression to stratify breast cancer

BACKGROUND

Argonaute-2 (Ago2) is an essential component of microRNA biogenesis implicated in tumourigenesis. However Ago2 expression and localisation in breast cancer remains undetermined. The aim was to define Ago2 expression (mRNA and protein) and localisation in breast cancer, and investigate associations with clinicopathological details.

METHODS

Ago2 protein was stained in breast cancer cell lines and tissue microarrays (TMAs), with intensity and localization assessed. Staining intensity was correlated with clinicopathological details. Using independent databases, Ago2 mRNA expression and gene alterations in breast cancer were investigated.

RESULTS

In the breast cancer TMAs, 4 distinct staining intensities were observed (Negative, Weak, Moderate, Strong), with 64.2% of samples stained weak or negatively for Ago2 protein. An association was found between strong Ago2 staining and, the Her2 positive or basal subtypes, and between Ago2 intensity and receptor status (Estrogen or Progesterone). In tumours Ago2 mRNA expression correlated with reduced relapse free survival. Conversely, Ago2 mRNA was expressed significantly lower in SK-BR-3 (HER2 positive) and BT-20 (Basal/Triple negative) cell lines. Interestingly, high levels of Ago2 gene amplification (10-27%) were observed in breast cancer across multiple patient datasets. Importantly, knowledge of Ago2 expression improves predictions of breast cancer subtype by 20%, ER status by 15.7% and PR status by 17.5%.

CONCLUSIONS

Quantification of Ago2 improves the stratification of breast cancer and suggests a differential role for Ago2 in breast cancer subtypes, based on levels and cellular localisation. Further investigation of the mechanisms affecting Ago2 dysregulation will reveal insights into the molecular differences underpinning breast cancer subtypes.

Renal artery dysplasia with hypertension in neurofibromatosis

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MR imaging of renal transplants

Fifty-six MR studies were obtained in 32 renal transplant patients, by using T1-weighted, spin-echo, and inversion-recovery pulse sequences. The findings, particularly the loss of corticomedullary differentiation, and the extent of vascular penetration into the renal parenchyma, were compared with the clinical and histologic diagnosis of transplant rejection. Thirteen MR studies on 11 patients with clinically normal renal transplants demonstrated normal corticomedullary differentiation. Renal vessels extended into the parenchyma in all 11 patients and to the cortex in 38%. In 37 MR studies on 22 patients with a clinical or histologic diagnosis of acute and/or chronic transplant rejection, the corticomedullary differentiation was normal in 8%, faint in 24%, and absent in 68%. Renal parenchymal vessels were visualized in 32%, but extended to the level of the cortex in only 8%. In 68% of the studies with transplant rejection, no parenchymal vessels were seen. When the corticomedullary differentiation was either faint or absent, the vascular pattern was normal in 6%; in 68% of cases no parenchymal vessels could be identified. We conclude the corticomedullary differentiation and the renal vascular pattern are useful parameters in the evaluation of renal transplant rejection.

Metabolic aspects of the regulation of systemic pH

Catabolism of protein produces CO2, NH4+, and HCO3-. Mammals readily lose CO2 through the lungs, but the bicarbonate produced in metabolism of a typical diet (in humans, approximately 1 mol/day from approximately 100 g of protein) would cause alkalosis if not disposed of. Air-breathing animals solve this problem by incorporating NH4+ into organic compounds in which N is not protonated; thus each NH4+ ion loses a proton in the course of the synthesis. These protons serve to titrate HCO3-. In mammals, ureagenesis is the pathway by which protons are liberated from NH4+. The rate of ureagenesis therefore determines the rate of disposal of bicarbonate, and must be an important factor in the maintenance of pH homeostasis. Ammonium ion that is not needed for urea synthesis is packaged into glutamine by the liver. Hepatic glutamine synthetase is localized in the last rank of cells around the pericentral venule; thus glutamine synthetase cannot compete for NH4+ or interfere with the control of pH by urea synthesis. Ammonium excretion in the urine does not represent excretion of acid, and is not stoichiometrically related to renal generation of bicarbonate. The quantitatively major processes by which the HCO3-/CO2 ratio, and hence the pH, is regulated in blood and interstitial fluid are excretion of CO2 through the lungs and disposal of HCO3- as a consequence of ureagenesis in the liver.

Focal segmental glomerulosclerosis in Hodgkin's disease

Development of Nil disease and focal segmental glomerulosclerosis (FGS) in sequential renal biopsies is reported in a patient with Hodgkin's lymphoma. Although steroid resistance was demonstrated, a complete and sustained clinical remission of the renal lesion followed anti-Hodgkin's chemotherapy. These findings support the hypothesis that Nil disease and FGS are manifestations of the same clinical entity.

Naproxen-induced nephropathy in systemic lupus erythematosus

A 34-year-old female with an 8-month history of systemic lupus erythematosus and intermittent naproxen use presented with acute oliguric renal failure, hypoalbuminemia, 4+ proteinuria, and an active urinary sediment. The clinical picture suggested a rapidly progressive lupus glomerulonephritis. Renal biopsy, however, demonstrated chronic, active interstitial nephritis without evidence of immune deposits by immunofluorescence or electron microscopy. Nonsclerotic glomeruli revealed diffuse foot process fusion without cellular proliferation. These findings were consistent with nonsteroidal anti-inflammatory drug induced nephropathy. Discontinuation of naproxen and institution of corticosteroid therapy was followed by improvement in renal function and remission of nephrotic syndrome. This case represents the first report of nonsteroidal antiinflammatory drug nephropathy associated with systemic lupus erythematosus.

Mechanisms of excretion of some low-molecular-weight bases in the rat

1. The excretion of structural analogues of ammonia in acidic and alkaline urine was investigated. The lipid-soluble compounds n-propylamine, n-butylamine and n-amylamine and the water-soluble compounds hydrazine and methylhydrazine resemble ammonia in being more rapidly excreted in acidic urine. By contrast, the excretion of the water-soluble amines methylamine and ethylamine is unaffected by changes in urinary pH.

2. Arguments are advanced, based on the results, that pH-dependent excretion of ammonia is due to diffusion of the water-soluble un-ionized fraction through the aqueous phase of the cell membrane, and the same applies to the hydrazines. However that of n-propylamine and the higher-molecular-weight alkylamines is due to diffusion through the lipid phase of the cell membrane. The data suggest that this latter form of diffusion is the more rapid one.

3. After injection of glutamyl-γ-methylamide and the corresponding ethylamide, both methylamine and ethylamine excretions are significantly higher in acidosis, rising further in chronic acidosis. This indicates that the glutaminase II pathway of ammonia genesis increases in activity in the acidotic rat in vivo.

Bartter's syndrome - a dilemma of cause and effect

Six interrelated abnormalities of Bartter's syndrome are analyzed-juxtaglomerular hyperplasia, angiotensin resistance, altered kallikrein-kinin system, hyperprostaglandinuria, hypokalemia, and chloride-losing nephropathy. Arguments are advanced that any one of these could be the proximate cause and result in all the others. By the same token, each abnormality could be a consequence of any of the others and, furthermore, modulate the others by negative or positive feedback. Despite many recent insights, available data do not permit a definitive conclusion as to the locus of the primary abnormality. Rather, the syndrome presents as a remarkable biological counterpart to an electronic integrated circuit. The altered physiology of Bartter's syndrome is reviewed and the pathogenesis of the syndrome analyzed in the light of recent literature.