[Fulminant Wilson's disease in Costa Rica. Clinico-pathological study of 7 cases]. / Enfermedad de Wilson fulminante en Costa Rica. Estudio clínico patologico de 7 casos.

In the last eighteen years, from 1972 to 1989, around 150 cases of Wilson's disease have been diagnosed in Costa Rica (6/100.000 inhabitants). In the San Juan de Dios Hospital, 120 cases have been studied during this period, seven of whom died with a picture of acute hepatic insufficiency, hemolytic anemia, encephalopathy, intestinal bleeding and renal insufficiency. In four of the cases, postmortem histopathologic studies were done with high resolution microscopy, which revealed extensive submassive necrosis of the liver, with severe cholestatic, lytic and acidophilic necrosis with nodular, irregular regeneration and specially microvacuolar steatosis, different from that observed in other forms of fulminant hepatitis. With the clinical, laboratory and histopathologic findings, we concluded that fulminant Wilson's disease is a well-defined pathological clinical entity of fatal evolution with no response to therapy, including early treatment with penicillamine and steroids.

Myonecrosis induced in mice by a basic myotoxin isolated from the venom of the snake Bothrops nummifer (jumping viper) from Costa Rica.

The mode of action of a basic myotoxin isolated from Bothrops nummifer venom was studied. This myotoxin is a basic polypeptide of 13,000 mol.wt, with a high content of lysine and aspartate, as well as of hydrophobic amino acids. It lacked phospholipase A2 activity when tested on several substrates at different pH values. Upon i.m. injection into mice, the toxin induced early morphological alterations typified by 'delta lesions' in the periphery of muscle fibers, an indication that the plasma membrane was the first cellular structure to be affected. Afterwards, necrotic cells had a clumped appearance, which then changed to a more hyaline histological pattern. Removal of necrotic material by phagocytes was followed by skeletal muscle regeneration, with the presence of myoblasts, myotubes and fully regenerated myofibers. The toxin induced a rapid and drastic drop in muscle creatine and creatine kinase contents of injected muscle, as well as an increase in serum levels of the enzymes lactic dehydrogenase and creatine kinase. Moreover, total muscle calcium increased significantly after toxin administration. Myotoxin induced a dose-dependent release of peroxidase entrapped in liposomes made from muscle phospholipids. The lack of phospholipase A2 activity in this toxin, together with the observation that it behaved as an amphiphilic protein in charge-shift electrophoresis, suggests that it might penetrate and disorganize muscle plasma membrane by means of a hydrophobic interaction.

Relationship of upper body fat distribution to serum glucose and lipids in a Costa Rican population.

Present models of the relation between subcutaneous fat distribution and serum biochemistries have been based largely on U.S. White populations. To determine interpopulational differences in that relation, we measured 68 clinically normal adult Costa Ricans aged 17-32. Data collected included six skinfolds: triceps, subscapular, suprailiac, umbilical, anterior mid-thigh, and medial calf; height, weight, and four fasting serum parameters: glucose, triglyceride, cholesterol, and high-density lipoprotein (HDL). Correlations between standardized skinfold ratios and biochemistries were highest--on the order of 0.40-0.50--for upper-lower body contrasts to triglyceride and cholesterol in males and to glucose and HDL in females. Canonical correlation analysis, with body mass index partialed out, found significant correlations for the first male variate and the first two female variates. The first male variate was positively weighted on subscapular fatness and on triglyceride and cholesterol, respectively. The two female skinfold variates were positively weighted on subscapular and on outer limbs, respectively, while their corresponding biochemical variates were weighted on glucose and triglyceride and on cholesterol and HDL, respectively. These findings are generally consistent with those based on U.S. populations but suggest that in non-Anglo populations, upper trunk fatness may be more relevant than anterior waist fatness to biochemical dysfunction.

Simple spectrophotometric determination of urinary albumin by dye-binding with use of bromphenol blue.

This procedure for routine quantification of albumin in urine is based on the dye-binding properties of albumin with bromphenol blue. The absorbance of 100 microL of urine mixed with 3 mL of color reagent is measured against blank reagent at 610 nm after 30 s. Results vary linearly with albumin concentration up to 6 g/L. The reaction is pH independent in the physiological range. It is not subject to substantial interference by uric acid, creatinine, calcium, sodium chloride, or bilirubin. The presence of globulins produces a small positive error. Within-run precision (CV) was 4.8, 1.5, and 0.9%, and day-to-day precision was 11.2, 2.0, and 1.9%, for samples containing albumin at about 0.1, 1.0, and 6.0 g/L, respectively. Results by a radial-immunodiffusion method (x) correlated well with those by the proposed method (y): r = 0.986; y = 0.98x + 0.096; n = 64. The method can also be used to detect globulins, such as Bence Jones protein, by measuring the ratio of the absorbance at 30 min to that at 30 s.

Micromethod for analysis for chloride in physiological fluids.

A micromethod for the analysis for chloride, based on the chemical precipitation of silver chloride by radial diffusion through agar gel containing silver nitrate, is described. The method is simple to run, requires little or no instrumentation, and requires only 10 mul of sample. Results by coulometric titration (Buchler Cotlove Chloridometer) correlated well for serum (r = 0.961), urine (r = 0.997), cerebrospinal fluid (r = 0.991), and sweat (r = 0.998). Other halide ions or protein do not interfere. Precision studies gave a within-day reproducibility (CV) of 1.3% and a day-to-day variability of 2.1% for a serum sample averaging 115 mmol/liter.

Automated determination of serum ceruloplasmin activity with o-dianisidine dihydrochloride as substrate.

An automated method for the enzymatic determination of ceruloplasmin with o-dianisidine dihydrochloride as substrate is described. The method enables the measurement of 30 samples per hour with a coefficient of variation (day-to-day) of 2.8%. Results correlate well (r equals 0.99 with those obtained by the corresponding manual method