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Biomedical subjects

G M Lum

Publications and source records attributed to G M Lum.

32 records · Page 2Linked to original sources
PubMed1984

Systemic hypertension in infants with bronchopulmonary dysplasia.

Thirteen of 30 infants with bronchopulmonary dysplasia demonstrated systolic blood pressure readings above 113 mm Hg on at least three separate occasions. In contrast, only one of 22 infants without BPD developed hypertension. The onset of hypertension often followed discharge from the nursery, was transient, and responded well to antihypertensive medication. Its significance is exemplified by the presence of left ventricular hypertrophy in three infants and a cerebrovascular accident in one child. We conclude that systemic hypertension is a significant problem in infants with BPD, and recommend close monitoring of blood pressure during their follow-up care.

Bronchopulmonary Dysplasia↗
PubMed1984

Aluminum loading in children with chronic renal failure.

Plasma aluminum levels were measured in 17 children with chronic renal failure who were receiving aluminum containing antacids for the control of hyperphosphatemia. Seven children were on hemodialysis, five on peritoneal dialysis, and five were awaiting dialysis with creatinine clearances between 10 to 20 cc/min/1.73 m2. Plasma aluminum levels correlated directly with oral aluminum dosage; extremely high levels were documented in small, nondialyzed children. Bone aluminum levels were measured in four children with high plasma levels and confirmed significant aluminum loading. Other factors such as the level of aluminum in dialysate and tap water were measured and were not contributory. All patients with plasma aluminum levels greater than 100 micrograms/liter had signs of aluminum toxicity and were receiving greater than 75 mg/kg/day of elemental aluminum orally. We concluded that children who require greater than 30 mg/kg/day of elemental aluminum to control hyperphosphatemia should have plasma aluminum levels monitored and/or be considered for other forms of therapy including more restricted diets and earlier or more aggressive dialysis.

Adolescent↗
PubMed1983

Early renal involvement in acute lymphoblastic leukemia and nonHodgkin's lymphoma in children.

Clinical manifestations of kidney disease, particularly renal failure, caused by malignant infiltration in patients with acute lymphoblastic leukemia or nonHodgkin's lymphoma have been described rarely. We report 1 case of acute lymphoblastic leukemia and 3 cases of nonHodgkin's lymphoma in which renal disease was the only or one of the presenting manifestations of malignancy. Of these patients 2 had rapidly progressive renal failure with nephromegaly, 1 presented with bilateral abdominal masses caused by severe nephromegaly and with microscopic hematuria, and 1 had microscopic hematuria without nephromegaly. In all 4 patients kidney biopsy revealed malignant infiltration. In the 2 patients who presented with renal failure kidney function promptly returned to normal after chemotherapy and irradiation of the kidneys. Prompt and correct diagnosis of nephropathy, when it is the only or one of the presenting signs of acute lymphoblastic leukemia or nonHodgkin's lymphoma, is necessary to expedite initiation of specific antitumor therapy.

Child↗
PubMed1982

Serum antibody response to pneumococcal vaccine in children with nephrotic syndrome.

Children with nephrotic syndrome are susceptible to serious pneumococcal disease and may be immunodeficient on the basis of abnormal humoral immune responses to natural antigens or immunoglobulin loss during relapse. As part of an ongoing study to evaluate pneumococcal anticapsular antibody concentration and immunologic competence, 27 steroid-responsive and six steroid-resistant patients with nephrotic syndrome, and 12 age-matched control subjects, were vaccinated with polyvalent pneumococcal vaccine. Antibody responders were defined as patients with at least a twofold increase in antibody after vaccination as well as an antibody concentration greater than 200 ng of anticapsular antibody nitrogen per milliliter (ngN/ml) after vaccination. Pneumococcal antibody concentrations before and after vaccination were significantly depressed in steroid-resistant patients when compared with control subjects (P less than .002) and with the steroid-responsive nephrotic syndrome group (P less then .001). Steroid-responsive nephrotic children who were not receiving corticosteroid therapy at the time of vaccination had significantly higher antibody concentrations to five pneumococcal types before vaccination and to seven types after vaccination compared with control subjects (P less than .05). Fewer steroid-responsive patients receiving corticosteroids achieved antibody concentrations greater than or equal to 200 ngN/ml against type 19F compared with patients not receiving steroids or with control subjects (P less than .05). These results suggest that pneumococcal vaccine is immunogenic in children with steroid-responsive nephrotic syndrome and may protect these patients from disease due to pneumococcal types contained in the vaccine.

Adolescent↗
PubMed1980

Glycerol kinase deficiency with neuromuscular, skeletal, and adrenal abnormalities.

Two brothers with a recently described inborn error of metabolism characterized by glyceroluria, hyperglycerolemia, and generalized glycerol kinase deficiency had moderate psychomotor retardation, spasticity, growth failure, a nonspecific myopathy, osteoporosis, and adrenal insufficiency. Glycerol kinase activity in leukocytes and cultured fibroblasts was less than 5% of control values. Hepatic and renal tissue obtained at autopsy in one patient had similarly low enzyme activity. Thus the deficiency of glycerol kinase in these patients appears to be generalized and heritable, though the relationship of the clinical phenotype to the enzymatic defect is not yet established.

Bone and Bones↗
PubMed1979

Serum concentrations of 24,25(OH)2D in uremic children: a reflection of renal function.

The mean serum concentration of 24,25(OH)2D determined by competitive protein-binding radioassay was significantly lower in ten uremic children maintained on hemodialysis (0.82 +/- 0.43[SD] ng/ml) than in ten patients with impaired renal function not requiring hemodialysis (1.30 +/- 0.54 ng/ml, P less than 0.05), or in 12 normal children (2.98 +/- 1.57 ng/ml, P less than 0.01). The serum levels of 250HD were similar in all groups. There were significant (P less than 0.01) positive correlations between the serum concentration of 24,25(OH)2D or the ratio 24,25(OH)2D/25OHD and the creatinine clearance. The serum concentration of 24,25(OH)2D was significantly decreased also in six anephric adults relative to normal adult values. The data indicate that production of 24,25(OH)2D is impaired in subjects with compromised renal function. Inasmuch as the major active metabolite of Vitamin D, i.e., 1,25(OH)2D, is requried for renal synthesis of 24,25(OH)2D measurement of the latter metabolite may provide a convenient method for assessment of renal vitamin D metabolism. The role of this metabolite in the pathogenesis of renal osteodystrophy remains speculative.

Child↗
PubMed1978

Asymptomatic hematuria and proteinuria in children: differentiating the causes.

In dealing with asymptomatic hematuria or proteinuria in the pediatric population, the physician should begin with an organized, logical sequence of diagnostic steps, including careful review of the history, physical findings, and laboratory data. If serious glomerular disease is suspected (eg, presentation atypical of acute poststreptococcal glomerulonephritis, nephrotic syndrome beyond the usual age for idiopathic nephrotic syndrome of childhood, renal insufficiency, severe hypertension), biopsy is probably inevitable, and early referral to a nephrologist is urged.

Acute Disease↗
PubMed1977

Effect of dialysis on hearing acuity.

In order to determine the effect of dialysis on hearing acuity, 20 patients on chronic maintenance hemodialysis or peritoneal were followed with hearing examinations every 6 months over a follow-up period of 1-4 years. While 70% of the study group had some measureable hearing loss at the beginning of the study, 75% of the patients showed no deterioration of hearing loss during the follow-up period. It is suggested that hearing deficits in chronic renal failure are common and multifactorial in etiology, and that most patients undergoing chronic dialysis show no further deterioration in hearing acuity.

Adolescent↗
PubMed1977

In vivo effect of indomethacin to potentiate the renal medullary cyclic AMP response to vasopressin.

In a previous study we demonstrated that indomethacin potentiated the hydro-osmotic action of vasopressin in vivo. It was hypothesized that this action of indomethacin was due to its ability to suppress renal medullary prostaglandin synthesis, since in vitro studies have suggested that prostaglandins interfere with the ability of vasopressin to stimulate production of its intracellular mediator, cyclic AMP. In the present study this hypothesis was tested in vivo. Anesthetized rats undergoing a water diuresis were studied. In a control group, bolus injections of 200 muU of vasopressin caused a rise in urinary osmolality (Uosm) from 124 +/- 6 to 253 +/- 20 mosmol/kg H2O (P less than 0.005). In a group treated with 2 mg/kg of indomethacin the same dose of vasopressin caused a significantly greater (P less than 0.001) rise in Uosm from 124 +/- 7 to 428 +/- 19 mosmol/kg H2O. Medullary tissue cyclic AMP rose from 9.4 +/- 0.9 to 13.4 +/- 1.7 (P less than 0.05) pmol/mg tissue protein after vasopressin administration in animals receiving no indomethacin, while in indomethacin-treated animals there was a significantly greater rise (P less than 0.001) in medullary cyclic AMP from 10.4 +/- 0.9 to 21.6 +/- 2.1 pmol/mg tissue protein in response to the vasopressin injections. In neither control animals nor indomethacin-treated animals were there significant changes in renal hemodynamics, as measured by clearance techniques. Indomethacin, when given alone, had no effect on Uosm or medullary tissue cyclic AMP. Indomethacin did, however, reduce medullary prostaglandin E content from 84.7 +/- 15.0 to 15.6 +/- 4.3 pg/mg tissue. This study has shown that indomethacin, in a dose which suppresses medullary prostaglandin content, potentiates the ability of vasopressin to increase the tissue content of its intracellular mediator, cyclic AMP. Indomethacin caused no demonstrable inhibition of cyclic AMP phosphodiesterase. Therefore, it seems likely that indomethacin enhanced the ability of vasopressin to increase medullary cyclic AMP levels by causing an increased production rather than decreased destruction of the nucleotide. We conclude that this action of indomethacin contributes to its ability to potentiate the hydro-osmotic action of vasopressin in vivo. A corollary to this conclusion is that endogenous medullary prostaglandin E's may be significant physiological modulators of the renal response to vasopressin.

Animals↗