Search PubMed⌕ Search

Biomedical subjects

P Justice

Publications and source records attributed to P Justice.

At least 19 recordsLinked to original sources

Intrinsic AHR in IL-5 transgenic mice is dependent on CD4(+) cells and CD49d-mediated signaling.

Overexpression of interleukin (IL)-5 by the airway epithelium in mice using the rat CC10 promoter (NJ.1726 line) leads to several histopathologies characteristic of human asthma, including airway hyperreactivity (AHR). We investigated the contribution of B and T cells, as well as CD4 expression, to the development of AHR in IL-5 transgenic mice. NJ.1726 mice on a T cell or CD4 knockout background, but not on a B cell knockout background, lost intrinsic AHR. These effects occurred without decreases in IL-5 or eosinophils. We further investigated the contribution of alpha(4)-integrin signaling to the development of AHR in IL-5 transgenic mice through the administration of anti-CD49d (alpha(4)-integrin) antibody (PS/2). Administration of PS/2 resulted in immediate (16-h) inhibition of AHR. The inhibition of AHR was not associated with a decrease in airway eosinophils. These studies demonstrate that, despite the presence of increased levels of IL-5 and eosinophils in the lungs of NJ.1726 mice, CD4(+) cells and alpha(4)-integrin signaling are necessary for the intrinsic AHR that develops in IL-5 transgenic mice.

Animals↗

Membrane-binding domains and cytopathogenesis of the matrix protein of vesicular stomatitis virus.

The membrane-binding affinity of the matrix (M) protein of vesicular stomatitis virus (VSV) was examined by comparing the cellular distribution of wild-type (wt) virus M protein with that of temperature-sensitive (ts) and deletion mutants probed by indirect fluorescent-antibody staining and fractionation of infected or plasmid-transfected CV1 cells. The M-gene mutant tsO23 caused cytopathic rounding of cells infected at permissive temperature but not of cells at the nonpermissive temperature; wt VSV also causes rounding, which prohibits study of M protein distribution by fluorescent-antibody staining. Little or no M protein can be detected in the plasma membrane of cells infected with tsO23 at the nonpermissive temperature, whereas approximately 20% of the M protein colocalized with the membrane fraction of cells infected with tsO23 at the permissive temperature. Cells transfected with a plasmid expressing intact 229-amino-acid wt M protein (M1-229) exhibited cytopathic cell rounding and actin filament dissolution, whereas cells retained normal polygonal morphology and actin filaments when transfected with plasmids expressing M proteins truncated to the first 74 N-terminal amino acids (M1-74) or deleted of the first 50 amino acids (M51-229) or amino acids 1 to 50 and 75 to 106 (M51-74/107-229). Truncated proteins M1-74 and M51-229 were readily detectable in the plasma membrane and cytosol of transfected cells as determined by both fluorescent-antibody staining and cell fractionation, as was the plasmid-expressed intact wt M protein. However, the expressed doubly deleted protein M51-74/107-229 could not be detected in plasma membrane by fluorescent-antibody staining or by cell fractionation, suggesting the presence of two membrane-binding sites spanning the region of amino acids 1 to 50 and amino acids 75 to 106 of the VSV M protein. These in vivo data were confirmed by an in vitro binding assay in which intact M protein and its deletion mutants were reconstituted in high- or low-ionic-strength buffers with synthetic membranes in the form of sonicated unilammelar vesicles. The results of these experiments appear to confirm the presence of two membrane-binding sites on the VSV M protein, one binding peripherally by electrostatic forces at the highly charged NH2 terminus and the other stably binding membrane integration of hydrophobic amino acids and located by a hydropathy plot between amino acids 88 and 119.

1,2-Dipalmitoylphosphatidylcholine↗

Beta 2-microglobulin clearance in neonates: index of tubular maturation.

Serum and urinary beta 2-microglobulin (beta 2M) were studied by enzyme immunoassay in 28 normal neonates at day 1 and day 4 of life in relation to gestational age (GA) and postnatal age (PNA). The infants were grouped according to GA; 10 with GA ranging from 32 to 35 weeks (mean 33.5 weeks) and 18 with GA ranging from 36 to 41 weeks (mean 38.3 weeks). Serum beta 2M varied directly with both GA and PNA. When values for serum beta 2M were related to conceptional age (CA), a significant positive correlation was present for all the infants studied (r = 0.68, P less than 0.01). Fractional excretion of beta 2M (FE beta 2M) decreased as a function of both GA and PNA. When a comparison of FE beta 2M was made in infants of all CA, a significant inverse correlation was noted for infants with CA less than or equal to 35 weeks (r = -0.89, P less than 0.001). The fall in FE beta 2M reached a plateau by 36 weeks. The highest FE beta 2M (33%) was observed in infants of 32 weeks CA who had the lowest filtered beta 2M (F beta 2M). No statistically significant relationship between changes in FE beta 2M and fractional urine flow rate was observed within each of the CA categories (infants less than or equal to 35 weeks, r = 0.21, P = 0.28; infants greater than or equal to 36 weeks, r = 0.25, P = 0.18).(ABSTRACT TRUNCATED AT 250 WORDS)

Gestational Age↗

Superoxide dismutase and glutathione peroxidase abnormalities in erythrocytes and lymphoid cells in Down syndrome.

After validating a superoxide dismutase (SOD) assay, this enzyme was measured together with a large series of cell age sensitive marker enzymes, in the erythrocytes of 24 persons with the 24 persons without Down syndrome. In addition to the expected elevation of SOD-1, significant elevations of erythrocyte glutathione peroxidase (GSHPxase) and phosphofructokinase activities were found in Down syndrome. None of these changes could be accounted for by a decreased mean red cell age. The elevation of GSHPxase was also found in lymphoid cells but does not represent a gene dose effect at this locus. Rather, the elevation of GSHPxase in Down syndrome may represent an adaptive metabolic response to the increased hydrogen peroxide produced by the triplicated SOD-1 gene dose in trisomy 21. Since tissue GSHPxase activity can be manipulated via the enzyme's obligatory selenium co-factor, our data suggest the need to establish blood and tissue levels of selenium in Down syndrome and to correlate selenium, GSHPxase and phenotypic dysfunction in this disorder.

Adult↗

Vitamin D-resistant rickets associated with epidermal nevus syndrome: demonstration of a phosphaturic substance in the dermal lesions.

A 5-year-old boy was found to have severe rickets in association with hyperpigmented, linear, verrucous, epidermal tumors, typical of the epidermal nevus syndrome. Normocalcemia (9.6 mg/dl), hypophosphatemia (2.0 mg/dl), elevated serum alkaline phosphatase concentration (313 IU), decreased renal tubular reabsorption of phosphorus (35%), radiologic evidence of rickets, and lack of response to usual therapeutic doses of vitamin D suggested hypophosphatemic vitamin D-resistant rickets. Therapy with vitamin D in doses to 750,000 IU and oral phosphate, 2.0 gm/day, failed to induce healing of the rickets. A subtotal parathyroidectomy performed when the patient was 9 years old was also without effect. When he was 12 years old several fibroangiomas on the face and left lower limb were excised. Within three months all biochemical abnormalities resolved and radiologic evidence of healing was observed. A portion of excised tissue was homogenized and injection of the supernate into a 6-week-old puppy induced excessive phosphaturia. The data suggest that the rickets was induced by a phosphaturic substance extractable from the tumors.

Calcium↗

Folic acid nonresponsive homocystinuria due to methylenetetrahydrofolate reductase deficiency.

Four siblings from a family with 11 children of Irish ancestry were observed to suffer from an essentially identical clinical illness, consisting of delayed psychomotor development in infancy and childhood, severe mental retardation, and upper motor neuron dysfunction. Death occurred at an early age in three siblings. In cases in which detailed physical examinations were performed, ectopia lentis, marfanoid features, and severe bony deformities were absent. Homocystinuria, homocystinemia, relatively normal concentrations of methionine and cystine in tissue fluids, and absence of methylmalonic aciduria were found. A deficiency of methylenetetrahydrofolate reductase was demonstrated in cultured skin fibroblasts from two siblings. Postmortem examination of two of the three patients who died showed extensive vascular thrombosis. No biochemical improvement was observed in the surviving child following treatment with large doses of folic acid.

Adolescent↗

Detection of homozygotes and heterozygotes with methylenetetrahydrofolate reductase deficiency.

Specific enzyme assay is required for the diagnosis of homocystinuria due to methylenetetrahydrofolate reductase deficiency. A rapid and accurate method has been developed using "pure" peripheral lymphocyte preparations. Triplicate determinations showed highly reproducible results. With the use of the mean of triplicate determinations in the presence of flavinadenine dinucleotide, there was complete segregation among the homozygotes, heterozygotes, and normal subjects. This method provides a rapid diagnosis in affected subjects and a simple means for the determination of heterozygotes for genetic counseling.

Alcohol Oxidoreductases↗

A defect in tryptophan metabolism.

Oral tryptophan loading tests were performed in a patient with photosensitive pellagra-like skin rash and cerebellar ataxia but without hyperaminoaciduria. Plasma tryptophan concentrations after loading were similar in the patient and control subjects. Average urinary excretion of tryptophan in the patient from 0 to 6 and 6 to 12 hr was 2.69 and 2.58 mumol/kg, respectively; that in the control subjects was 0.82 and 0.34 mumol/kg, respectively. However, the average renal clearance of tryptophan during the first 6 hr of the loading tests in the patient was 0.757 ml plasma/1.73 m2 and that in the control subjects was 0.706 ml plasma/1.73 m2. Renal excretion of kynurenine in the patient was markedly decreased. The average from 0 to 6 and 6 to 12 hr in the patient was 1.90 and 1.13 mumol/kg, respectively; that in the control subjects was 12.90 and 18.15 mumol/kg, respectively. Under ultraviolet light, paper chromatograms of urine from the patient showed a deficiency of xanthurenic acid, kynurenic acid, kynurenine, and formylkynurenine. The deficiency of formylkynurenine in the patient's urine was confirmed by staining the paper chromatograms with Ehrlich's reagent. The patient was "sensitive" to oral nicotinic acid treatment; however, oral nicotinamide was well tolerated with improvement in the photosensitive skin rash.

Cerebellar Ataxia↗

Phenylketonuria.

Explore the source record for details and available documents.

Female↗

Biochemical, morphological and hybrid studies in hyperprolinemic mice.

Hyperprolinemia, hyperprolinuria and hydroxyprolinuria were observed in PRO/Re mice. Hepatic proline oxidase activity in PRO/Re mice was markedly deficient. It was demonstrated that the deficiency of proline oxidase activity was not due to the presence of an inhibitor. The mutant enzyme in PRO/Re showed no difference in heat stability but had a poor affinity for the substrate, L-proline as compared to normal enzymes. There was no significant proteinuria or hematuria in PRO/Re mice. Their serum protein and blood urea nitrogen were normal. Morphologic studies by light and electron microscopy demonstrated no abnormality in the renal tissues of PRO/Re up to 6 months of age, suggesting that hyperprolinemia did not cause renal damage. Pedigree studies showed that F1 generation (PRO/Re x CD 1) had approximately 50 percent of normal proline oxidase activity and significantly higher plasma proline. The distribution of hepatic proline oxidase activity in F2 GENERATION (F1 x F1) was characteristic of an autosomal recessive trait.

Amino Acid Metabolism, Inborn Errors↗