Multiple-crystal acute polyarthritis

A patient with acute polyarthritis due to crystal-positive simultaneous gout and pseudogout affecting different joints is described. The case emphasises the importance of aspirating more than one involved joint and carefully searching for crystals in patients with acute arthritis involving 2 or more joints, particular those in whom the diagnosis of multiple crystalline joint disease is considered.

Ultrafiltrable calcium and magnesium in ultrafiltrates of serum prepared with the Amicon MPS-1 system

We evaluated the Amicon micropartition system (MPS-1) for preparing ultrafiltrates of serum for use in evaluating ultrafiltrable Ca and Mg. We found no adsorption of either to the filter and 99.6% retention of serum proteins on the membrane. Ultrafiltrate volumes recovered (100-450 microL) varied with centrifugation time (10-30 min) and temperature. Centrifugation time did not affect the measured concentration of ultrafiltrable calcium and magnesium, and pH change in the 1-mL serum specimen during a 30-min centrifugation at room temperature was negligible. There was an inverse relationship between temperature and ultrafiltrable Ca and Mg concentrations. The precision (CV) between filters ranged from 1.2 to 5.1% for ultrafiltrable Ca and 1.5 to 2.7% for ultrafiltrable Mg. The correlation between ultrafiltrable Ca (y) and ionized Ca (x) in samples from 115 patients with calcium-related metabolic disorders was good (y = 1.04x + 0.18; r = 0.9128). We find the MPS-1 to be a simple and convenient tool for the rapid production of serum ultrafiltrates.

Ultrafiltrable calcium and magnesium in ultrafiltrates of serum prepared with the Amicon MPS-1 system

We evaluated the Amicon micropartition system (MPS-1) for preparing ultrafiltrates of serum for use in evaluating ultrafiltrable Ca and Mg. We found no adsorption of either to the filter and 99.6% retention of serum proteins on the membrane. Ultrafiltrate volumes recovered (100-450 microL) varied with centrifugation time (10-30 min) and temperature. Centrifugation time did not affect the measured concentration of ultrafiltrable calcium and magnesium, and pH change in the 1-mL serum specimen during a 30-min centrifugation at room temperature was negligible. There was an inverse relationship between temperature and ultrafiltrable Ca and Mg concentrations. The precision (CV) between filters ranged from 1.2 to 5.1% for ultrafiltrable Ca and 1.5 to 2.7% for ultrafiltrable Mg. The correlation between ultrafiltrable Ca (y) and ionized Ca (x) in samples from 115 patients with calcium-related metabolic disorders was good (y = 1.04x + 0.18; r = 0.9128). We find the MPS-1 to be a simple and convenient tool for the rapid production of serum ultrafiltrates.

Adrenal and hepatic calcium stearate crystal deposits in dogs fed a thiamine-deficient diet

The nature and histologic environment of birefringent crystals found incidentally at necropsy in the liver and adrenal glands of dogs fed a thiamine-deficient diet were studied. The crystals were identified as calcium stearate by ultrastructural and x-ray microdiffraction techniques. Crystals were observed intracellularly within cytoplasmic vacuoles and extracellularly within sinusoids. Generally, crystals were also observed in pair-fed controls that were given a purified diet (equal in weight to that consumed by the thiamine-deficient animals) plus supplemental thiamine. Crystal deposits were found in trace amounts in a few of the ad libitum-fed controls. Although thiamine deficiency may be involved in promoting crystal deposition in the adrenal cortex, calcium stearate crystal formation within the adrenal glands and the liver appears unrelated to dietary thiamine deficiency per se, but is probably related to deficiency of an unidentified nutrient in the purified thiamine-deficient diet.

The effect of calcium and magnesium ions on calcium pyrophosphate crystal formation in aqueous solutions

Calcium pyrophosphate crystal formation has been associated clinically with hypercalcemic states (hyperparathyroidism) and hypomagnesemia. We studied aqueous solutions at pH 7.4, 37 degrees C, [Na+] = 140 nM over a range of calcium chloride/magnesium chloride/sodium pyrophosphate concentrations to determine the effect of calcium and magnesium ions on crystal formation. We found that CPPD(T) and CPPD(M) could form under different ionic conditions. Low [Mg++] and [PPi] favoured CPPD(T) whereas higher [Mg++] and [PPi] favoured CPPD(M). At [Mg++] = 1.0 mM a calcium magnesium pyrophosphate crystal phase designated CMPP2 formed. As [Mg++] affects the crystal phase formed more than equimolar [Ca++], we conclude that ionic magnesium deficiency may be a clinically important determinant in calcium pyrophosphate dihydrate crystal formation.

Calcium pyrophosphate crystal formation in model hydrogels. II. Hyaline articular cartilage as a gel

We studied calcium pyrophosphate crystal formation in an in vitro cartilage system. Two parallel troughs were excavated in tibial plateau articular cartilage obtained postmortem. One well was filled with solid sodium pyrophosphate, the other with calcium chloride. After incubation for 24 h at either 10 degrees C or 37 degrees C the precipitate band between the troughs was analyzed for the size and nature of crystals present. In subsequent experiments, the cartilage was pretreated by laceration, contusion, trypsin or hyaluronidase denaturation. We found that cartilage denaturation resulted in formation of larger crystals but that the crystal product in all experiments was identical, alpha CaNa2P2O7.4H2O a nonphysiologic crystal.

Cholesterol crystals in osteoarthritic joint effusions

Cholesterol crystals were demonstrated in synovial fluids from 4 patients with knee osteoarthritis and recurrent synovial effusions. Large crystals (10-80 micros) were readily identifiable by their characteristic plate-like morphology. Some fluids also contained numerous smaller (1-5 microns) irregular, rod and needle shaped crystals. Identification of these crystals as cholesterol was established by x-ray diffraction analysis (2 fluids) and by ultrastructural studies (1 fluid). This study documents the occurrence of cholesterol crystals in osteoarthritic effusions, but their precise pathogenetic significance remains unclear.

Calcite sputum lith. Characterization by analytic scanning electron microscopy and X-ray diffraction

The chemical identification by x-ray diffraction and analytic scanning electron microscopy of a sputum lith weighing 1 mg is described. These technics demonstrated that the lith was composed of rhombohedral calcium carbonate (calcite). Since different crystal species form under different chemical conditions, these precise, nondestructive analytic technics should have wide application in the investigation not only of a bronchial liths but also of other microcrystalline tissue deposits.

Calcium pyrophosphate crystal formation in aqueous solutions

Pseudogout is characterized by the deposition of calcium pyrophosphate dihydrate, triclinic [CPPD(T)] and calcium pyrophosphate dihydrate, monoclinic [CPPD(M)] crystals in articular connective tissues. We studied aqueous solutions over a range of calcium chloride/sodium pyrophosphate concentrations to determine the ionic conditions under which these particular salts form. At 37 degrees C, CPPD(T) forms when [PPi]t greater than or equal to 10(-4), while formation of CPPD(M) occurs at 10(-3) M < [PPi]t less than or equal to 10(-2) M. When [Na+]t > 120 mM, calcium disodium pyrophosphates precipitate. With 1 mM Mg++, CPPD(M) forms at [PPi]t > 10(-3) M, mixed with a calcium magnesium pyrophosphate at [PPi]t greater than or equal to 10(-2) M. We conclude that CPPD(T) and CPPD(M) crystals form in a restricted ratio and range of [Ca++]t and [PPi]t and that other ions, particularly Mg++ and Na+, affect the nature of the crystal products formed.

Effect of a dorsal dermal surgical wound on the chemical response of rat abdominal skin to chronic administration of sodium diphenylhydantoin

A dorsal dermal surgical wound inflicted five days before excision of abdominal skin from young rats that were under treatment with daily injections of sodium diphenylhydantoin (100 or 50 mg/ kg) greatly modified the dermal chemical response to this drug that was observed in unwounded animals. Sodium diphenylhydantoin failed to increase wound rupture strength.