Formulas for Calculated Osmolarity and Osmolal Gap: A Study of Diagnostic Accuracy.

Background: The osmolal gap has been used for decades to screen for exposure to toxic alcohols. However, several issues may affect its reliability. We aimed to develop equations to calculate osmolarity with improved performance when used to screen for intoxication to toxic alcohols.

Acute Kidney Injury and Renal Recovery with the Use of Aminoglycosides: A Large Retrospective Study.

Background: Recent acute kidney injury (AKI) guidelines, based on studies performed a decade ago, recommend avoiding aminoglycosides (AGs) in patients at risk of AKI. Whether present patient characteristics and management have changed this risk is uncertain. We determined the current incidence, risk factors and outcomes of AG-AKI.

Classification and labeling of industrial products with extreme pH by making use of in vitro methods for the assessment of skin and eye irritation and corrosion in a weight of evidence approach.

Classification and labeling of products with extreme pH values (≤ 2 or ≥ 11.5) is addressed in chemicals legislation. Following determination of pH and alkaline/acid reserve, additional in vitro tests are needed, especially to substantiate results less than corrosive.

FSGS permeability factor-associated nephrotic syndrome: remission after oral galactose therapy.

Some cases of nephrotic syndrome in focal and segmental glomerulosclerosis (FSGS) are associated with a circulating factor, the FSGS permeability factor (FSPF). Galactose has a high affinity for FSPF, and experimental data suggest that it could reduce its activity. We describe the case of a 48-year-old male with a nephrotic syndrome found to be resistant to corticosteroids, immunosuppression and plasmaphaeresis.

Mycotoxins in indoor environments.

Exposure to mycotoxins produced by toxigenic molds growing in damp indoor spaces has been difficult to assess. Monitoring methods limit the characterization of inhalation exposure of any bioaerosol, especially that of mycotoxins. Biomarkers promise better ability to determine mycotoxin exposures 1.

Could cytoplasmic concentration gradients for sodium and ATP exist in intact renal cells?

In renal cells, the Na+ pump maintains a transmembrane concentration gradient for sodium ensuring the net reabsorption of sodium with or without cotransported species. This process requires a significant fraction of the ATP turnover of proximal tubules and thick ascending limbs. To understand the potential regulatory influences of Na+ and ATP on the activity of the Na+ pump in these nephron segments, the apparent kinetics of the membrane-bound Na+-K+ ATPase and of the cellular Na+ pump were studied in different preparations of dog proximal tubules and thick ascending limbs (tubular suspensions, tissue homogenates, and basolateral membrane vesicles) obtained from dog kidney cortex and red medulla.

The penetration of oral ciprofloxacin into the aqueous humor, vitreous, and subretinal fluid of humans.

We examined ciprofloxacin levels in the aqueous humor, vitreous, or subretinal fluid in 40 patients undergoing cataract extraction, vitrectomy, or scleral buckling. Ciprofloxacin, 750 mg, was administered orally an average of 17 1/2 and 5 1/2 hours preoperatively. We obtained mean ciprofloxacin levels of 0.

Monitoring of the effects of dysprosium shift reagents on cell suspensions.

The effects of two widely used paramagnetic shift reagents for cationic NMR, dysprosium tripolyphosphate [Dy(PPP)2(7-)] and dysprosium triethylenetetramine hexaacetate [Dy(TTHA)3-], on the cell structure of dog and human erythrocytes, dog kidney cortical tubules and rat hepatocytes were investigated. The effect of shift reagents on cell integrity was monitored by measuring the hematocrit values for erythrocytes, by measuring the lactate dehydrogenase (LDH) release and by electron microscopy for cortical tubules and hepatocytes. The quantitation of the dyprosium penetration inside cells was accomplished by atomic absorption, atomic emission and neutron activation.

Basolateral glucose transport in distal segments of the dog nephron.

The transport of glucose by canine thick ascending limbs (TAL) and inner medullary collecting ducts (IMCD) was studied using tubule suspensions and membrane vesicles. The uptake of D-[14C(U)]glucose by a suspension of intact TAL tubules was reduced largely by phloretin (Pt), moderately by phlorizin (Pz), and completely suppressed by a combination of both agents. A selective effect of Pz on the transport of [14C]alpha-methyl-D-glucoside, but not on 2-[3H]deoxyglucose, was also observed in TAL tubules.

Variable NMR visibility of intracellular sodium induced by Na(+)-substrate cotransport in dog cortical tubules.

The intracellular sodium concentration [( Na+]i) of dog kidney cortical tubules was monitored by flame photometry and 23Na NMR using dysprosium tripolyphosphate as shift reagent. Upon addition of substrates cotransported with sodium, flame photometry showed an increase in [Na+]i while no change (glutamine, glucose) or even a decrease (lactate) in the Na+i NMR signal was observed. This discrepancy could not be explained by a lack of ATP prior to the addition of substrates or by a decrease of NMR visibility of Nai+ induced by binding of substrate to membrane transporters (and pump).

Relationship between intracellular ATP and the sodium pump activity in dog renal tubules.

To examine the potential effect of the cellular ATP concentration and of the phosphate potential on the function of the sodium pump in intact renal cells, the ATP content of dog cortical tubules was first modified by a 30-min preincubation with one of the following effectors: 5 or 10 mM fructose, 2.5 mM adenosine 5'-monophosphate (AMP), or 2.5 mM adenosine in the presence of substrates (10 mM glutamine + 1 mM glutamate with either 10 mM lactate (low ATP) or 10 mM pyruvate (high ATP)).

An incubation system for the NMR study of kidney tubules.

Isolated kidney cortical tubules require a very rapid oxygen supply and mechanical agitation to be optimally functional. A sample chamber in which a tubule suspension is oxygenated by recirculating oxygen gas inside a coil of dialysis fibers to avoid cell loss through bubbling and in which the tubules are agitated by a gas-driven turbine has been designed. In such a system, dog cortical tubules (35-45 mg/ml) were found to be metabolically stable for more than 3 h as indicated by linear lactate consumption and glucose production.