PubMed Health⌕ Search

Biomedical subjects

E D Brewer

Publications and source records attributed to E D Brewer.

At least 37 records · Page 2Linked to original sources
PubMed1998

The insulin-like growth factor axis and growth in children with chronic renal failure: a report of the Southwest Pediatric Nephrology Study Group.

Children with chronic renal failure (CRF) are often growth recarded despite normal serum levels of GH and insulin-like growth factors (IGFs). Recent studies suggest that excess IGF-binding proteins (IGFBPs) in the 35-kDa fractions of CRF serum contribute to CRF growth failure. This report characterizes the relationship between IGFBP-3 and IGF peptides in the serum of growth-retarded CRF children. Size-exclusion chromatography at pH 7.4 found IGFBP-3 and IGFs almost exclusively in the 150-kDa fractions of normal serum, where their molar stoichiometry was approximately 1:1. However, similar chromatography of CRF serum found a molar excess of IGFBP-3 over total IGFs in the 150-kDa fractions and large amounts of IGFs in the 35-kDa fractions. In the 150-kDa fractions of CRF serum, IGFBP-3 was present in normal amounts, but a greater than normal amount was in the form of a 29-kDa IGFBP-3 fragment. Treatment of these CRF children with recombinant human GH increased the molar excess of IGFBP-3 over total IGFs in the 150-kDa fractions, the amount of IGFBP-3 and total IGFs in the 150-kDa fractions, and the amount of IGFs, but not IGFBPs, in the 35-kDa fractions. These data suggest that in untreated CRF children, proteolysis of IGFBP-3 in the 150-kDa fractions releases IGFs to the excess IGFBPs in the 35-kDa fractions, but insufficient IGF is released to overcome the growth-inhibiting effects of these excess IGFBPs. Treatment with recombinant human GH increases levels of IGFs and IGFBP-3 in the 150-kDa fractions, and subsequent IGFBP-3 proteolysis releases sufficient IGF to overcome the growth inhibitory effects of excess IGFBPs in the 35-kDa fractions of CRF serum.

Child↗
PubMed1998

Increasing incidence of childhood class V lupus nephritis.

OBJECTIVE: Class V lupus nephritis (LN) is reported to occur in 0-23% of patients with LN. To better characterize pediatric LN, we determined at a single center (1) the relative frequency of Class V LN on first and serial biopsies, (2) the frequency of transformation between LN classes on serial biopsies, (3) types of treatment received and outcome to date of different classes of LN. METHODS: All pediatric renal biopsies from 1985 to the present performed for diagnosis and classification of suspected LN were reviewed. Biopsy results were grouped into 2-3 year time intervals to assess trends in the distribution of WHO class diagnoses over time. RESULTS: Sixty patients underwent 97 renal biopsies. Class V LN was present in 28% (17/60) of patients on first biopsy, and in 37% (22/60) on most recent biopsy. Class V LN on first biopsy increased from 17% (8/46) before 1995 to 64% (9/14) after 1995 (p < 0.001). Age at presentation, age at biopsy, time to biopsy, and types of treatment did not differ before and after 1995. Transformation to Class V LN occurred in 19% (5/27) of patients having repeat biopsies. No transformation from Class V LN occurred on repeat biopsy. Renal outcome was available in 48 patients with followup of 4.7 +/- 3.2 years for Class V LN, and 5.2 +/- 2.4 years for non-Class V LN. Five percent (1/20) of Class V LN patients had renal dysfunction or had died compared to 21% (6/28) of non-Class V LN patients (p = NS). CONCLUSION: We found (1) a greater frequency of Class V LN than has been reported, (2) a recent increase in the incidence of Class V LN at our institution, (3) frequent transformation between classes on serial biopsies, and (4) no regression of Class V lesions in patients who had repeat biopsies.

Adolescent↗
PubMed1997

Modulation of growth factors by growth hormone in children with chronic renal failure. The Southwest Pediatric Nephrology Study Group.

Anthropometric measurements and circulating growth factors were studied serially in 44 prepubertal children with growth failure and chronic renal failure (GFR = 10 to 40 ml/min/1.73 m2) who were randomized to receive either recombinant human growth hormone (rhGH; N = 30) or no treatment (N = 14). RhGH was given as Nutropin, 0.05 mg/kg/day, and the studies were carried out at baseline and after 3 and 12 months. At baseline, serum insulin-like growth factor binding protein (IGFBP)-1 and -2 levels were, while IGFBP-3 levels were not, higher than those of children with normal renal function. In addition, height SDS at baseline correlated inversely with serum IGFBP-2 levels (r = -0.461, P = 0.0016), but did not correlate significantly with any other factor. After 12 months of study, the 30 children receiving rhGH showed: (i) greater increase in height (9.1 +/- 2.8 vs. 5.5 +/- 1.9 cm, P < 0.0001); (ii) increases in serum levels of IGF-I, IGF-II, free IGF-I, IGFBP-3 and acid labile subunit (ALS); (iii) a greater decrease in serum IGFBP-1 levels; and (iv) no significant difference in serum IGFBP-2 levels, when compared to the 14 control patients. The change in height SDS after 12 months of rhGH (+0.8) in the 30 treated children correlated significantly and positively with serum ALS, IGFBP-3, total IGF, IGF-I, IGF-II and free IGF-I levels measured during treatment. These observations suggest that, in children with growth failure associated with chronic renal failure: (i) IGFBP-2, and not IGFBP-3, is likely to be a growth inhibitor; (ii) rhGH stimulates catch-up growth in part by increasing serum levels of IGF peptides; and (iii) linear growth is influenced by the balance between growth stimulating IGFs and growth inhibitory IGFBPs.

Age Determination by Skeleton↗
PubMed1997

Insulin-like growth factor-binding protein-6 levels are elevated in serum of children with chronic renal failure: a report of the Southwest Pediatric Nephrology Study Group.

Previous studies suggest that growth retardation in children with chronic renal failure (CRF) results in part from inhibition of insulin-like growth factor (IGF) action by excess serum IGF-binding proteins (IGFBPs). Excess IGFBPs in CRF serum include IGFBP-1, -2, and -3 and a diffuse approximately 24- to 28-kDa IGFBP band identified by [125I]IGF ligand blot. The present studies characterized this diffuse approximately 24- to 28-kDa band. Initial studies identified this band as IGFBP-6, because it was immunoprecipitated by antiserum raised against a synthetic peptide of human IGFBP-6 (hIGFBP-6). Additional [125I]IGF ligand blots found that the immunoprecipitated band was 1) recognized by [125I]IGF-II but not [125I]IGF-1, 2) more abundant in CRF than in normal serum, and 3) more abundant in serum from dialyzed than nondialyzed prepubertal CRF children. Using the hIGFBP-6 antiserum in a specific and sensitive RIA, we found that serum IGFBP-6 levels were 4.7 +/- 1.7 nmol/L in 10 normal prepubertal children, 21.4 +/- 6.1 nmol/L in 44 nondialyzed prepubertal CRF children, 73.5 +/- 14.4 nmol/L in 7 dialyzed prepubertal CRF children, and 94.6 +/- 26.2 nmol/L in 14 dialyzed pubertal CRF children. IGFBP-6 levels were also elevated in 71 nondialyzed European children with CRF. In nondialyzed CRF children, serum IGFBP-6 levels 1) correlated inversely with the glomerular filtration rate, 2) did not correlate with height SD score, and 3) were not altered by 12 months of daily recombinant hGH treatment. In summary, a specific antiserum and RIA were used to demonstrate elevated levels of intact IGF-II-binding IGFBP-6 in serum of CRF children. We postulate that the excess IGFBP-6 may modulate the action of IGF-II on target tissues.

Adolescent↗
PubMed1996

Characterization of insulin-like growth factors and their binding proteins in peritoneal dialysate.

Serum insulin-like growth factors (IGFs), which circulate bound to specific IGF binding proteins (IGFBPs), must exit the intravascular space before acting on target tissues. Little is known about the nature of IGF/IGFBPs in extravascular fluids of patients with chronic renal failure (CRF). Peritoneal dialysate (PD) was studied since, after a short incubation, PD contains proteins which have entered an extravascular space; thus, IGF/IGFBP forms in PD are more likely than serum forms to interact with target tissues. IGF-I and IGF-II, and IGFBPs 1-4, were readily identified by specific immunoassays and/or 125iodine-IGF ligand blotting of simultaneously obtained PD and serum samples from seven CRF children; IGFBP-3 was a major IGFBP in PD as in serum. Where quantitated, IGF and IGFBP levels in PD were approximately 10% of serum concentrations. After separation of PD and serum by size-exclusion chromatography, serum had more IGFBP-3 in 150-kilodalton (kDa) than 35-kDa fractions, while PD had far less IGFBP-3 in 150-kDa than 35-kDa fractions. Immunoblot studies revealed a major 29-kDa IGFBP-3 fragment, in addition to intact 41- and 38-kDa IGFBP-3 forms, in PD and CRF serum; the 29-kDa form predominated in the 35-kDa PD fractions. These data suggest that the 29-kDa fragment is the IGFBP-3 form most likely to modulate IGF effects on target tissues of CRF individuals.

Adolescent↗
PubMed1994

Dietary protein and growth in infants with chronic renal insufficiency: a report from the Southwest Pediatric Nephrology Study Group and the University of California, San Francisco.

This report describes growth and nutrition data from the feasibility phase of a clinical trial that was designed to evaluate the effect of diet protein modification in infants with chronic renal insufficiency (CRI). The purpose of the proposed trial was to compare the safety (effect on growth in length) and efficacy [effect on glomerular filtration rate (GFR)] of a diet with a low protein: energy (P:E) ratio versus a control diet in such patients. Twenty-four infants with GFRs less than 55 ml/min per 1.73 m2 were randomly assigned at 8 months of age to receive either a low-protein (P:E ratio 5.6%) or control protein (P:E ratio 10.4%) formula, which resulted in average protein intakes of 1.4 and 2.4 g/kg per day in the low and control groups, respectively. Overall energy intakes over a 10-month period of study averaged 92% +/- 12% recommended dietary allowance (RDA) for length in the low-protein group and 92 +/- 15% RDA in the control group. Weight for age standard deviation scores (SDS) were comparably low in both groups at the time of randomization (low-protein--2.0 +/- 1.3, control -1.9 +/- 1.1) and at the end of the study (low -1.9 +/- 1.2, control -1.7 +/- 0.9). Length for age SDS at entry tended to be lower in the low-protein group but were not significantly different in the two groups (low -2.2 +/- 1.4 vs. control -1.7 +/- 1.4). However, at 18 months the low-protein group had a significantly lower SDS for length (-2.6 +/- 1.2 vs. -1.7 +/- 1.4).(ABSTRACT TRUNCATED AT 250 WORDS)

Academic Medical Centers↗
PubMed1993

Characterization of insulin-like growth factor binding protein-3 in chronic renal failure serum.

IGF-binding protein-3 (IGFBP-3), usually found as glycosylated 41- and 38-kD forms, is the major serum IGFBP during extrauterine life. In normal serum IGFBP-3 binds one IGF peptide and one acid-labile (alpha) subunit in a high-molecular-weight (MW) complex of 150 kD. By RIA, an excess of IGFBP-3 is present in chronic renal failure (CRF) serum, where it reportedly accumulates at low MW (25-55 kD) rather than as part of the 150-kD complex. To further evaluate IGFBP-3 forms in CRF, sera were obtained from seven healthy adolescents and seven adolescents with CRF. By RIA, IGFBP-3 levels were higher in CRF than normal sera (15.4 +/- 2.2 versus 10.1 +/- 2.1 micrograms/mL). High-MW (150-kD) fractions of CRF and normal sera, obtained by neutral size-exclusion chromatography, had equal amounts of IGFBP-3 by RIA. However, a second RIA peak of IGFBP-3, present in low-MW (35-kD) fractions of CRF but not normal sera, could account for the higher IGFBP-3 levels of CRF serum. [125I]IGF ligand blots of whole serum and serum fractions, either with or without prior precipitation by IGFBP-3 antiserum, found levels of 41- and 38-kD IGFBP-3 forms to be similar between CRF and normal whole sera and located these forms in the high-MW (150-kD) fractions of CRF and normal sera.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1992

New syndrome involving the visual, auditory, respiratory, gastrointestinal, and renal systems.

A previously undescribed fatal multisystem syndrome involving the eyes, ears, lungs, intestines, and kidneys occurred in sibs. They both presented during early childhood with cataracts, otitis media, intestinal malabsorption, chronic respiratory infection, and failure to thrive. Later, they developed recurrent pneumonia (one was shown to have immotile bronchial cilia) and progressive azotemia leading to end-stage renal disease (ESRD) by late childhood. Both died of overwhelming infection (sepsis, meningitis). An autosomal recessive mode of inheritance is proposed since the normal parents were distant cousins, and 4 other sibs were normal.

Child, Preschool↗
PubMed1990

Hemolytic-uremic syndrome during an outbreak of Escherichia coli O157:H7 infections in institutions for mentally retarded persons: clinical and epidemiologic observations.

PURPOSE: To describe an outbreak of Escherichia coli O175:H7 infection resulting in a high rate of progression to hemolytic-uremic syndrome, and to attempt to identify predictors of and risk factors for progression. DESIGN: Case-control study among employees and comparison of daily clinical features in two groups: infected residents with subsequent development of HUS and those who had no complications. SETTING: Two institutions for retarded persons in Utah. PATIENTS: Twenty residents with E. coli O157:H7 infection (13 culture confirmed, 2 probable, and 5 possible); HUS developed in 8, and 4 died. Thirty-one infected employees (3 with culture-confirmed, 6 with probable, and 22 with possible infection). MEASUREMENTS AND MAIN RESULTS: In a case-control study among employees, infection was independently associated with eating ground beef from a single lot prepared at several barbecues and with close contact with a resident who had diarrhea. Five of eight residents in whom HUS developed had received trimethoprim-sulfamethoxazole, compared with none of seven who had no subsequent complications (p = 0.026); this finding may reflect antimicrobial treatment of patients with more severe illness. Compared with infected residents without complications, persons with HUS were younger (median age 13 vs 27 years, p = 0.043) and, by the third day of illness, had higher leukocyte counts (median 23.7 X 10(9)/L vs 9.1 X 10(9)/L, p = 0.018) and temperature (median 38.5 degrees C vs 37.0 degrees C, p = 0.016). Leukocytosis peaked on day 4, more than 24 hours before signs of HUS appeared. CONCLUSIONS: Food-borne outbreaks of E. coli O157:H7 in institutions may have devastating effects. Leukocytosis and fever may precede and predict HUS in patients with E. coli O157:H7 infection.

Adolescent↗
PubMed1990

Disorders of acid-base balance.

Acid-base disorders are common in sick children. This article is a practical guide to the differential diagnosis and treatment of simple and mixed acid-base disorders of children. Special attention is given to fundamentals of acid-base physiology, to clinical use of the Henderson equation, and to interpretation of readily available laboratory tests.

Acid-Base Equilibrium↗
PubMed1990

Growth of small children managed with chronic peritoneal dialysis and nasogastric tube feedings: 203-month experience in 14 patients.

This 203-month experience with CPD and NG feedings in 14 small children weighing less than or equal to 10 kg at initiation of CPD for ESRD, provides evidence that CPD and vigorous nutritional therapy is effective in maintaining and improving growth until a successful renal transplant can be performed. Nutritional therapy should be initiated early, if possible when growth begins to decline even before the onset of ESRD and the need for CPD. Infants who are less than or equal to 4 months old at initiation of CPD are more likely to have a complicated clinical course and poor growth, despite the provision of CPD and vigorous nutritional support. More experience with this group of patients is needed to determine appropriate therapy.

Child, Preschool↗
PubMed1989

Hemolytic uremic syndrome associated with glomerular disease.

Secondary hemolytic uremic syndrome (HUS) is uncommon. When it occurs, it is usually in association with pregnancy, malignancy, severe hypertension, drugs, or collagen vascular diseases. It has rarely been reported in patients with glomerular disease. Two such patients with secondary HUS are described. A 17-month-old girl with hematuria and the nephrotic syndrome, negative antistreptolycin O (ASO) titer, and low serum levels of C3 and C4 developed oliguria, progressive azotemia, thrombocytopenia, and microangiopathic hemolytic anemia. A kidney biopsy showed fibrin in glomerular capillaries and cresentic membranoproliferative glomerulonephritis. A 22-year-old man with a 16-year history of relapsing minimal change nephrotic syndrome had been in remission for 5 years when he experienced nephrotic syndrome relapse and developed thrombocytopenia, microangiopathic hemolytic anemia, and renal failure. A kidney biopsy revealed foot process fusion and obstruction of glomerular capillaries with fibrin and platelets. These cases illustrate that HUS can occur in association with other glomerular diseases and should be considered when thrombocytopenia and hemolytic anemia occur in a nephritic or nephrotic patient.

Adult↗
PubMed1988

Platelet activation and prostacyclin supporting capacity in the loin pain hematuria syndrome.

The loin pain hematuria syndrome has been characterized as a constellation of severe recurrent flank pain and hematuria, occurring predominantly in young women. We studied a 17-year-old woman who had recurrent right flank pain, gross hematuria, and fever, without evidence of urinary tract infection. Her physical exam was remarkable for right costovertebral angle tenderness and a normal BP. Her urinalysis showed blood and protein but her creatinine clearance and 24-hour urinary calcium excretion were normal. A kidney biopsy was remarkable for arteriolar subintimal fibrous thickening and fibrin deposition, but no glomerulonephritis. Her peripheral hemostasis evaluation was normal except for circulating platelet aggregates and elevated fibrinopeptide A levels. On two occasions, her serum was unable to normally support prostacyclin (PGI2) production by cultured human umbilical endothelial cells, as measured by radioimmunoassay (RIA) of its stable metabolite 6-keto-PGF alpha. Blood samples from the right renal vein and inferior vena cava revealed a selective elevation of fibrinopeptide A in the right renal venous effluent. The presence of circulating platelet aggregates and elevated levels of fibrinopeptide A (a cleavage product of fibrin) suggests that platelet activation and fibrin deposition may play a role in the pathogenesis of this disorder. The inability of her serum to normally support the production of the potent antiplatelet and antithrombotic substance, PGI2, could represent a primary renovascular endothelial cell defect.

Adolescent↗