Pharmacokinetics of recombinant human erythropoietin in children with chronic renal failure.

Basal erythropoietin (Epo) levels and single dose-pharmacokinetics of recombinant human erythropoietin (rhuEpo) were investigated in 8 predialysis (PD) patients (mean age 11.6 +/- 1.4 years) and in 8 patients on continuous ambulatory peritoneal dialysis (CAPD) (mean age 12.

Atypical pattern of adenylyl cyclase activity in the adrenal medulla with age.

Concurrent reduced physiological responsiveness often occurs in those tissues in which signal transduction coupled to adenylyl cyclase is diminished with age. In the adrenal medulla, the major physiological functions are catecholamine synthesis and release, and these functions are increased with age. To examine whether the sensitivity or efficacy for adenylyl cyclase stimulation is altered with age, we determined the vasoactive intestinal peptide (VIP) and forskolin activation of adenylyl cyclase in adrenal medullary membranes from young (4 month) and senescent (24 month) male F-344 rats.

Tyrosine hydroxylase gene expression in varying forms of human pheochromocytoma.

We performed a comparative study of catecholamine content, tyrosine hydroxylase (TH) activity, and TH mRNA levels in normal human adrenals and various clinical forms of human pheochromocytoma. We studied sporadic, benign intra-adrenal chromaffin tumors and other non-malignant intra-adrenal tumors associated with multiple endocrine neoplasia type 2B (MEN 2B) and von Hippel-Lindau disease along with one extra-adrenal malignant pheochromocytoma. Our findings suggest substantial differences in TH transcriptional rates or the stability of TH mRNA or both may contribute to altered TH expression in human chromaffin cells associated with "normal" adrenal tissues and various forms of pheochromocytoma and distinctive patterns of expression in the different settings in which these tumors arise.

Myocardial adenylyl cyclase type V and VI mRNA: differential regulation with age.

Myocardial beta-adrenergic signal transduction diminishes with age. This decrease is not due to a decrease in the number of beta-adrenoceptors, but may be a result of an impaired capacity to activate adenylyl cyclase (AC). Forskolin-stimulated AC activity is diminished, and the number of forskolin binding sites is decreased, suggesting that the decrease in signal transduction with age is a result of fewer AC catalytic units.

In vitro and in vivo antileukemic activity of B43-pokeweed antiviral protein against radiation-resistant human B-cell precursor leukemia cells.

B-cell precursor (BCP) leukemia is the most common form of childhood cancer and represents one of the most radiation-resistant forms of human malignancy. In this study, we examined the antileukemic efficacy of the B43 (anti-CD19)-pokeweed antiviral protein (B43-PAP) immunotoxin against radiation-resistant BCP leukemia cells. B43-PAP caused apoptosis of radiation-resistant primary BCP leukemia cells, killed greater than 99% of radiation-resistant primary leukemic progenitor cells from BCP leukemia patients, and conferred extended survival to severe combined immunodeficiency (SCID) mice xenografted with radiation-resistant human BCP leukemia.

Membrane-associated CD19-LYN complex is an endogenous p53-independent and Bc1-2-independent regulator of apoptosis in human B-lineage lymphoma cells.

CD19 receptor is expressed at high levels on human B-lineage lymphoid cells and is physically associated with the Src protooncogene family protein-tyrosine kinase Lyn. Recent studies indicate that the membrane-associated CD19-Lyn receptor-enzyme complex plays a pivotal role for survival and clonogenicity of immature B-cell precursors from acute lymphoblastic leukemia patients, but its significance for mature B-lineage lymphoid cells (e.g.

Infantile acute hemorrhagic edema: a variant of leukocytoclastic vasculitis.

Infantile acute hemorrhagic edema (IAHE) is a leukocytoclastic vasculitis that is confined to the skin without visceral involvement. Edema and purpuric lesions characterize the disease. The disorder has a dramatic onset, with a short, benign course and spontaneous resolution within several weeks.

Isolation and characterization of pokeweed antiviral protein mutations in Saccharomyces cerevisiae: identification of residues important for toxicity.

Pokeweed antiviral protein (PAP), a 29-kDa protein isolated from Phytolacca americana inhibits translation by catalytically removing a specific adenine residue from the 28S rRNA of eukaryotic ribosomes. PAP has potent antiviral activity against many plant and animal viruses, including human immunodeficiency virus. We describe here development of a positive selection system to isolate PAP mutants with reduced toxicity.

Tyrosine hydroxylase expression in rat adrenal medulla: influence of age and cold.

Chronic and cold exposure is associated with an increase in adrenal medullary tyrosine hydroxylase (TH) activity and expression that may be important for the regulatory response to cold. Senescent rats do not maintain their body temperature as well as young rats. We investigated the ability of the catecholaminergic system of older rats to respond to cold stimulus.

Tuberculous osteomyelitis: an unusual case of tuberculous infection in a child undergoing continuous ambulatory peritoneal dialysis.

A 10-year-old boy on continuous ambulatory peritoneal dialysis had low-grade fever, pain and tenderness of the right shoulder; he had no history of infection or exposure to tuberculosis. The underlying granulomatous infection was diagnosed by histological examination of bone and the polymerase chain reaction with primer sequences specific for Mycobacterium tuberculosis. Special stains and cultures were negative.

Myosin heavy chain composition in young and old rat skeletal muscle: effects of endurance exercise.

The objective of this study was to determine the effects of age and exercise on the myosin heavy chain (MHC) composition of skeletal muscle. Young (3 mo) and old (22 mo) female specific pathogen-free barrier-reared Fischer 344 rats were randomly assigned to young untrained or young trained and old untrained or old trained groups, respectively. Young trained and old trained animals performed endurance exercise training on a motorized treadmill for 8 wk.

Haemostatic parameters in childhood nephrotic syndrome. (Is there any difference in protein C levels between steroid sensitive and resistant groups?).

Plasma protein C (PC) activity, prothrombin time (PT), partial thromboplastin time (PTT) and platelet count were studied in 23 children with nephrotic syndrome (NS) and AT III activity was determined in 15 children in the same group. All parameters were compared with those obtained in a group of 16 age matched healthy controls. Mean plasma AT III activity was significantly reduced in patients with NS (P < 0.

Unilateral renal atrophy and hypertension (imaging techniques in children with hyperreninaemic hypertension) (a case report).

A ten-year-old boy with hyperreninaemic hypertension is described. He had a normally functioning right kidney, as confirmed by ultrasonography and renal scintigraphy. Renal angiography was performed but the left kidney and the left renal artery could not be detected.

Influence of exercise training and age on uncoupling protein mRNA expression in brown adipose tissue.

The ability to regulate body temperature diminishes with age. Exercise training is known to increase cardiovascular performance, and there is some evidence of a cross-adaptation between exercise and cold tolerance in young rats. The present study was designed to examine the effects of physical training by treadmill running on the capacity for brown adipose tissue (BAT) thermogenesis in young and old rats.

Effect of chronic treatment with prazosin and L-arginine on the elevation of blood pressure during cold exposure.

Chronic exposure to cold (5 degrees C) is well known to increase both tyrosine hydroxylase (TH) activity in brown adipose tissue and systemic blood pressure. The effect of chronic dietary administration of the alpha-adrenergic antagonist, prazosin, and the amino acid, L-arginine, on both the elevation of blood pressure during exposure to cold and on TH activity and expression of TH mRNA in the adrenal glands of rats was studied. As observed previously, chronic exposure to cold increased systolic blood pressure significantly and induced cardiac hypertrophy.

Plants transformed with a mutant alfalfa mosaic virus coat protein gene are resistant to the mutant but not to wild-type virus.

Transgenic tobacco plants expressing the wild-type (wt) coat protein (CP) gene of alfalfa mosaic virus (AIMV) have been shown to be resistant to infection with viral particles and RNAs or to infection with viral particles only. The difference in resistance of these plants to RNA inocula was found to correlate with a difference in the expression level of the transgene. Plants expressing a mutant AIMV CP with the N-terminal serine residue changed to glycine have been shown to be susceptible to infection with wt viral particles or RNAs.

Influence of exercise training on myocardial beta-adrenergic signal transduction: differential regulation with age.

Exercise training is known to increase cardiovascular performance and decrease heart rate. Because activation of adenylyl cyclase is an important factor in beta-adrenergic signal transduction and in the decline in signal transduction with age, we hypothesized that some of the effects of exercise training may be mediated by changes in postreceptor activation of adenylyl cyclase. To this end, we assessed isoproterenol-, G protein-, and forskolin-mediated activation of adenylyl cyclase as well as G protein immunoreactivity in the myocardium from young and senescent F-344 rats with and without prior exercise training by treadmill running.

Congenital microcephaly and infantile nephrotic syndrome--a case report.

A 22-month-old girl with nephrotic syndrome and microcephaly is described. She had dysmorphic facies and psychomotor retardation. Her parents were first-degree relatives and one of her siblings had died with nephrotic syndrome and renal failure in infancy.

Thermoregulation with age: role of thermogenesis and uncoupling protein expression in brown adipose tissue.

To investigate whether attenuation of thermogenesis in interscapular brown adipose tissue (IBAT) may account for the loss of thermoregulation with age, we examined two indices of thermogenesis after two types of cold exposure: one in which the senescent rats maintained homeothermy and the other in which the senescent rats became hypothermic. To this end, we assessed body temperature, guanosine 5'-diphosphate (GDP) binding to the IBAT mitochondrial uncoupling protein (UCP) and the induction of UCP mRNA after both 1-hr and 48-hr mild cold exposures at 8 degrees C and after a more severe, 1-hr cold exposure at 4 degrees C in 3- and 24-month-old F-344 rats. Thermoneutrality was determined to occur at an ambient temperature of 26 degrees C in rats of both ages.

Vaginal ectopic ureter in a duplex system with renal dysplasia. A case report.

A 12-year-old girl with vaginal ectopic ureter in a duplex system associated with an extremely dysplastic upper segment who presented with a complaint of vaginal discharge is reported. The diagnostic approach with special reference to ultrasonography and computerized tomography is discussed.

The effect of phenobarbital on autonomic function and epileptogenic activity induced by the hippocampal injection of penicillin in cats.

This study addressed whether penicillin-induced epileptiform discharges in the right hippocampus produced associated autonomic dysfunction. The study also examined the effect of phenobarbital on the heart rate and blood pressure changes that were induced by the epileptiform discharges. The delay in onset of epileptiform activity at the site of injection ranged from 1 second to 16 minutes, and consisted of interictal discharges or ictal discharges.

Broad-spectrum virus resistance in transgenic plants expressing pokeweed antiviral protein.

Exogenous application of pokeweed antiviral protein (PAP), a ribosome-inhibiting protein found in the cell walls of Phytolacca americana (pokeweed), protects heterologous plants from viral infection. A cDNA clone for PAP was isolated and introduced into tobacco and potato plants by transformation with Agrobacterium tumefaciens. Transgenic plants that expressed either PAP or a double mutant derivative of PAP showed resistance to infection by different viruses.