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Biomedical subjects

G Lama

Publications and source records attributed to G Lama.

At least 19 recordsLinked to original sources
PubMed1992

Use of calcium excretion values to distinguish two forms of primary renal tubular hypokalemic alkalosis: Bartter and Gitelman syndromes.

Clinical or biochemical findings were reevaluated in 34 pediatric patients with primary renal tubular hypokalemic metabolic alkalosis. The patients were subdivided into two groups. Bartter syndrome (primary renal tubular hypokalemic metabolic alkalosis with normocalciuria or hypercalciuria) was diagnosed in 18 patients with molar urinary calcium/creatinine ratios greater than 0.20, and Gitelman syndrome (primary renal tubular hypokalemic metabolic alkalosis with magnesium deficiency and hypocalciuria) was diagnosed in 16 patients with molar urinary calcium/creatinine ratios less than or equal to 0.20 and plasma magnesium levels less than 0.75 mmol/L. Some clinically important differences between the groups were observed. Patients with Bartter syndrome were often born after pregnancies complicated by polyhydramnios (8/18) or premature delivery (7/18) and had short stature (11/18) or polyuria, polydipsia, and a tendency to dehydration (16/18) during infancy (12/18) or before school age (18/18). Patients with Gitelman syndrome had tetanic episodes (12/16) or short stature (3/16) at school age (14/16). We conclude that the Bartter and Gitelman syndromes represent two distinct variants of primary renal tubular hypokalemic metabolic alkalosis and are easily distinguished on the basis of urinary calcium levels.

Alkalosis↗
PubMed1990

Effects of natural beta-interferon and recombinant alpha-2B-interferon on proliferation, glucocorticoid receptor content, and antigen expression in cultured HL-60 cells.

In the current study, we investigated the effects of natural beta-interferon (beta-IFN) and recombinant alpha-2b-interferon (alpha-IFN) on the growth of the HL-60 cell line. Cells cultured in a medium that contains various concentrations (from 10 to 1000 IU/ml) of interferons showed a growth inhibition, which reaches the maximum after a 6-day treatment, at the highest dose used. Furthermore, we studied the effect of both beta-IFN and alpha-IFN on the level of glucocorticoid receptors. This was enhanced more than 30% with respect to control in HL-60 cells exposed for 24 hours to concentrations of beta-IFN that ranged from 100 to 1000 IU/ml. The increase of the receptor amount was seen even if cells were treated for 5 days, and was not accompanied by a modification of antigen expression of HL-60 cells. alpha-IFN did not modify the glucocorticoid receptor level substantially in our experimental conditions. Our data indicate that both beta-IFN and alpha-IFN regulate HL-60 cell proliferation. Additional studies are required to clarify if modifications of the receptor level induced by beta-IFN could be related to the modulation of hormone-sensitivity in this model.

Antigens↗
PubMed1990

The renal hemodynamic response following a meat meal in children with chronic renal failure and in healthy controls.

The renal hemodynamic response to a meat meal (2 g/kg BW) was studied in 11 healthy children and in 10 children with a mean plasma creatinine concentration of 2.6 +/- 0.1 mg/dl due to chronic renal failure (CRF) of various etiologies. In the healthy status, after a meat meal, the glomerular filtration rate (GFR) increased significantly from a baseline value of 119.0 +/- 5.0 to a peak of 159 +/- 5.8 ml/min x 1.73 m2; in CRF baseline GFR averaged 49 +/- 4.0 and at peak 76.6 +/- 7.2 ml/min x 1.73 m2 (p less than 0.005). The peak GFR response was reached earlier in healthy subjects than in CRF (p less than 0.05) and did not correlate with age or with baseline GFR. Renal plasma flow (RPF) in healthy controls increased from 532 +/- 32 at baseline to 646 +/- 42.9 ml/min x 1.73 m2 after the meal (p less than 0.005). Also in CRF after a meat meal there was a significant increase in RPF from 278 +/- 51 to 65 +/- 66 ml/min x 1.73 m2 (p less than 0.005). The filtration fraction was not affected. The percent increase over baseline values of GFR and RPF at the peak was significantly higher in diseased children. Renal reserve averaged 28.1 +/- 5.3 ml/min in diseased children and 39.7 +/- 5.2 ml/min (p less than 0.01). The data indicate that (1) a meat meal is a suitable method to recruit renal reserve in normal children and in children with chronic renal failure, and (2) the renal reserve is normal in chronic renal failure.

Adolescent↗
PubMed1990

Promoters and inhibitors of calcium urolithiasis in children.

We have evaluated the urinary excretion of promoting (calcium, phosphorus, uric acid, oxalate) and inhibiting (citrate, magnesium, glycosaminoglycans) factors of crystallization in subjects with idiopathic hypercalciuria and calcium urolithiasis and in a control group. The examined children had a free diet and were drug free for the last 2 weeks. They were not affected by malabsorption, D-RTA, urinary tract infection, or urinary tract malformation (factors interfering with urinary excretion of citrate and oxalate). In the patients with calcium urolithiasis, the daily urinary excretion of oxalate was significantly higher (p less than 0.01), and the urinary excretion of citrate was significantly lower (p less than 0.001) than in the subjects with idiopathic hypercalciuria and in the control group. Among the subjects with idiopathic hypercalciuria, those aged 4-9 years had a significantly reduced, though in the normal range, urinary excretion of citrate as compared with those aged 10-15 years (362 +/- 189 and 503 +/- 198 mg/g creatinine/24 h, respectively; p less than 0.01). Our data show that hypocitruria may play an important role in the pathogenesis of urolithiasis in children with idiopathic hypercalciuria. In these cases, the urinary citrate excretion was not inversely related to age, as has been suggested by other authors.

Calcium↗
PubMed1987

Phase contrast microscopy of the urine sediment for the diagnosis of glomerular and nonglomerular bleeding-data in children and adults with normal creatinine clearance.

In a pediatric and in an adult group of patients with hematuria and normal creatinine clearance overnight urine examination was carried out on 2 nonconsecutive days by means of phase contrast microscopy by two independent observers working in two different institutions. In this way it was possible to distinguish between patients on the basis of dysmorphic (glomerular) and isomorphic (nonglomerular) red cells in urine and to correlate the findings with the final diagnosis. A clear-cut indication (more than 80% of isomorphic and/or dysmorphic red cells) was obtained in 163 patients (102 of pediatric age) and final diagnosis of hematuria correlated with red-cell microscopy findings in 96.4% of glomerular diseases and in all cases of nonglomerular origin. Mixed hematuria (50-75% of dysmorphic red cells) was found in 2 cases of renal tuberculosis, 2 cases of polycystic kidney disease and in 1 child with viral meningoencephalitis with a bladder stone. The data indicate that the method is safe and accurate but further experience must be gathered for the many etiologies of glomerular and nonglomerular diseases hitherto not studied.

Adolescent↗