Pediatric chest-abdomen-pelvis and abdomen-pelvis CT images with expert organ contours.

Purpose: Organ autosegmentation efforts to date have largely been focused on adult populations, due to limited availability of pediatric training data. Pediatric patients may present additional challenges for organ segmentation. This paper describes a dataset of 359 pediatric chest-abdomen-pelvis and abdomen-pelvis Computed Tomography (CT) images with expert contours of up to 29 anatomical organ structures to aid in the evaluation and development of autosegmentation algorithms for pediatric CT imaging.

Extracellular nucleotides and apyrases regulate stomatal aperture in Arabidopsis.

This study investigates the role of extracellular nucleotides and apyrase enzymes in regulating stomatal aperture. Prior data indicate that the expression of two apyrases in Arabidopsis (Arabidopsis thaliana), APY1 and APY2, is strongly correlated with cell growth and secretory activity. Both are expressed strongly in guard cell protoplasts, as determined by reverse transcription-polymerase chain reaction and immunoblot analyses.

Characterization of tubular functional capacity in humans using para-aminohippurate and famotidine.

Background: Renal drug excretion by glomerular filtration and active tubular secretion may be altered by factors such as acute and chronic renal disease, nephrotoxins, and drug interactions. Thus, accurate and reproducible methods for quantitation of glomerular filtration rate (GFR) and tubular functional capacity are critical.

Methods: We utilized a four-step sequential infusion method to characterize anionic [para-aminohippurate (PAH)] and cationic (famotidine) tubular functional capacity in healthy volunteers.

Denitration of nitroaromatic compounds by arylnitrile radical cations.

Substituted nitrobenzenes react with substituted benzonitrile radical cations in an ion trap mass spectrometer by a novel ion/molecule reaction involving NO2 elimination. Formation of an arylated nitrile, Ar1+N identical to CAr2 (where Ar1, Ar2 = aryl), is indicated by collision induced dissociation and comparison with the behavior of the authentic ion. Ab initio calculations (MP2/6-31G*/ /HF/6-31G*) show the reaction of the unsubstituted compounds (Ar1, Ar2 = phenyl) to be exothermic by 48 kcal/mol, consistent with the experimental observation that the reaction rate decreases as the collision energy is increased.

Comparison of iothalamate clearance methods for measuring GFR.

Study Objective: To evaluate the bias and precision of three methods of measuring glomerular filtration rate (GFR) relative to a standard method.

Design: Prospective, outpatient study.

Setting: University-affiliated general clinical research center.

Impact of acute renal failure on mortality in end-stage liver disease with or without transplantation.

Background: Acute renal failure (ARF) is traditionally considered a poor prognostic factor in end-stage liver disease and is associated with a mortality approaching 90%. While the increased use of orthotopic liver transplantation (OLTX) has changed the outcome for patients with end-stage liver disease (ESLD), it is not clear whether this has affected the outcome of patients with ESLD and ARF.

Methods: We prospectively followed the course of ARF in 177 patients with ESLD being evaluated for OLTX.

Disposition of foscarnet during peritoneal dialysis.

Objective: To report the disposition of foscarnet in a patient undergoing peritoneal dialysis.

Case Summary: A 34-year-old man with AIDS received foscarnet for the treatment of esophageal cytomegalovirus. We characterized the clearance of foscarnet in this patient during continuous cyclic peritoneal dialysis (CCPD) and continuous ambulatory peritoneal dialysis (CAPD).

Malfunctioning peritoneal dialysis catheter repaired by laparoscopic surgery.

Objectives: To review peritoneal dialysis catheter failures and to describe a technique of repairing malpositioned catheters.

Design: Two prospective case reports utilizing this technique are reported.

Setting: A tertiary care hospital.

Cell lines for the production of recombinant adeno-associated virus.

Adeno-associated virus (AAV) is a replication-defective parvovirus that is being developed as a vector for human gene transfer. However, a major obstacle to commonplace usage of AAV vectors is the production of recombinant virions (rAAV) in sufficient quantities for not only human trials, but also for preclinical studies of basic biology, toxicology, and efficacy. Unfortunately, current methods for large-scale production are cumbersome and expensive.

Evaluation of platelet hyperfunction in hemodialysis patients receiving recombinant human erythropoietin.

There are data suggesting that recombinant human erythropoietin (rHuEPO) may induce thromboses in hemodialysis patients, possibly due to alterations in platelet function. In an earlier study, we found evidence of platelet hyperfunction in several patients 4 to 8 weeks following the start of rHuEPO therapy, which was begun shortly after hemodialysis was initiated. Studies were performed to examine the effects of rHuEPO on whole blood platelet aggregation and adenosine triphosphate (ATP) release independent of changes in hematocrit or the uremic state.

Desmopressin (d-DAVP) effects on platelet rheology and von Willebrand factor activities in uremia.

Bleeding times, von Willebrand activities, and platelet retentions were examined before and following d-DAVP in 13 uremic patients. Shortening of the bleeding time from 16.6 +/- 2.

Sustained remission of membranous glomerulonephritis after cyclophosphamide and prednisone.

Objective: To determine the effect of cyclophosphamide and prednisone on progressive renal failure and on nephrotic features in patients with membranous glomerulonephritis.

Design: Prospective, nonrandomized time series.

Setting: Outpatient clinic at a university medical center.

Ibuprofen-associated lipoid nephrosis without interstitial nephritis.

A report of ibuprofen-associated lipoid nephrosis without interstitial nephritis is presented. Previous reported cases had incomplete biopsy descriptions or concurrent interstitial disease. The patient responded to withdrawal of ibuprofen.

Long-term follow-up of aggressively treated idiopathic rapidly progressive glomerulonephritis.

Purpose: We wanted to examine the long-term effects of aggressively treating idiopathic rapidly progressive glomerulonephritis (RPGN), with a particular focus on clinically characterizing the patient population, assessing the short- and long-term effects of therapy on renal function, and determining complications of the therapy.

Patients And Methods: Twenty-three consecutive patients with RPGN were treated and followed from one to 11 years. On renal biopsy, 13 had immune complexes, eight had no immune complexes, and two had antiglomerular basement membrane deposits.

The effect of serum potassium on theophylline-induced seizures.

Generalized seizures may be associated with therapeutic or intentional theophylline overdose. Toxic levels of theophylline are also associated with a fall in potassium which could potentiate theophylline-induced seizures. To evaluate the role of serum potassium concentration in theophylline-induced seizures we investigated the seizure threshold in normokalemic and hyperkalemic rats during theophylline infusion to toxic levels.

Rupture of ovarian cyst: massive hemoperitoneum in continuous ambulatory peritoneal dialysis patients: diagnosis and treatment.

Two women on continuous ambulatory peritoneal dialysis (CAPD) developed recurrent episodes of hemoperitoneum while in the reproductive age group. Initially, both were thought to have mechanical problems with the peritoneal catheter system. A laparotomy was performed in the first patient, and a bleeding ovarian cyst was identified.

A rat model for hyperkalemia.

It is often necessary to have a small animal model for hyperkalemia for use in electrolyte and acid base experiments. In reviewing the literature, we found a paucity of such animal models, especially for acute hyperkalemia. We have had difficulty in inducing acute hyperkalemia in rats using potassium chloride alone either intravenously or intraperitoneally and felt the need for an easily reproducible small animal model for hyperkalemia.

Genital edema in patients on continuous ambulatory peritoneal dialysis. Report of 3 cases and review of the literature.

Severe genital edema is a well-described complication of continuous ambulatory peritoneal dialysis (CAPD). Leakage of dialysate fluid from defects in the peritoneum may occur from clinically detectable and undetectable inguinal hernias, defects at the catheter insertion site, or other defects in the peritoneal membrane. We describe 3 patients (who underwent five surgical procedures), illustrating the complexity of the problem.

Autosomal dominant polycystic kidney disease: presentation, complications, and prognosis.

Fifty-three symptomatic adults with autosomal dominant polycystic kidney disease were studied retrospectively for a mean follow-up of 12 years (range 10 months to 33 years). Diagnosis was confirmed by either x-ray, ultrasound, laparotomy, or autopsy. Commonest presenting clinical findings were flank pain (30%), hypertension (21%), symptomatic urinary tract infection (UTI) (19%), gross hematuria (19%), and palpable masses (15%).

Relationship of phosphate-dependent glutaminase activity to ammonia excretion in potassium deficiency and acidosis.

Ammonia production and excretion are elevated in potassium depletion alkalosis, although normally they are reduced in alkalosis and elevated in acidosis. Studies were conducted with or without acute acid loading in normokalemic rats or rats made chronically hypokalemic with deoxycorticosterone acetate and a potassium-deficient diet to examine the role of phosphate-dependent glutaminase (PDG) in regulating ammonia excretion. Renal cortical PDG rose fourfold, and urinary ammonia excretion (UAE) doubled in potassium depletion compared to potassium-repleted controls.

The use of streptokinase to treat renal artery thromboembolism.

The effects of streptokinase are difficult to determine. Furthermore, it has toxic side effects, and renal function may not recover from its use. However, because of favorable experiences with this drug in the early treatment of venous thromboembolism and following myocardial infarction, as well as the favorable findings with early perfusion in the dog model, the use of local streptokinase may be justified if the infusion is begun early, preferably within four to six hours.

Plasmapheresis as sole therapy in a patient with essential mixed cryoglobulinemia.

An 82-year-old woman with essential mixed cryoglobulinemia type II (IgM K IgG) presented with moderate renal failure and nephritic syndrome. Mesangiocapillary glomerulonephritis with mesangial and subendothelial granular deposits containing IgG, IgM, and C3 in conjunction with small-vessel vasculitis was seen on renal biopsy. Renal symptomatology preceded by a period of 10 months the development of leg ulcers and purpura.

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.