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N A Holtzman

Publications and source records attributed to N A Holtzman.

At least 91 records · Page 5Linked to original sources
PubMed1982

A survey to evaluate parental consent as public policy for neonatal screening.

Most states currently have laws which result in compulsory neonatal screening practices, despite a widespread consensus that participation in genetic services and programs should be voluntary. In 1976, Maryland adopted a regulation designed to respect parents' rights to refuse neonatal screening by imposing a parental consent requirement. The results of a study designed to evaluate the effects of this regulation are reviewed here. Many health care providers were unaware of the parental consent regulation. However, hospitals were generally in compliance with the technical stipulations of the regulations. There was little evidence that the regulation resulted in additional costs to the health care system, either in terms of hospital staff time or in terms of loss of efficiency in the number of infants screened. Mothers affected by the regulation were largely in favor of being informed about neonatal screening and learned a significant amount of new information from the disclosure process. They were almost evenly divided on whether they favored parental consent.

Adult↗
PubMed1980

The diagnosis of phenylketonuria: a report from the Collaborative Study of Children Treated for Phenylketonuria.

One hundred ninety-five infants who met diagnostic criteria for enrollment in the Collaborative Study of Children Treated for Phenylketonuria (PKU) underwent a standard three-day challenge with 180 mg/kg/day of phenylalanine for confirmation of diagnosis. A sustained rise in serum phenylalanine levels of greater than 20 mg/dl was observed in 166 infants (85.1%), compatible with the diagnosis of classical PKU. In the remaining 29 infants (14.9%), the serum phenylalanine concentration either did not reach 20 mg/dL or, having achieved this level, subsequently declined below this point by 72 hours. It was agreed that these 29 patients had variant PKU and they were dropped from the Collaborative Study. We recommend that all infants diagnosed as having classic PKU undergo a challenge to confirm the diagnosis and need for continued treatment.

Humans↗
PubMed1979

Prevention: rhetoric and reality.

No single strategy is capable of preventing untimely deaths and disabilities. In the United States in particular, the contribution of medical care is limited by inadequate provision of services (particularly to the poor), inappropriate training of physicians, and unnecessary costs. Lack of knowledge about disease universally limits medicine's effectiveness. Among nonmedical strategies, campaigns for life-style change are most likely to succeed in those with the lightest burden of illness. Efforts to increase individual responsibility might well reduce health expenditures, but at the same time the disparity in health between rich and poor will increase. Restrictions on the use of harmful substances and on the manufacture of toxic or hazardous products, along with humanization of the work process itself, would reduce deaths from cancer, heart disease, and violence; however, resistance to these changes is, and will remain, great. The socioeconomic and environmental changes that are necessary to afford each citizen an equal opportunity for optimal health will be adopted slowly, if at all. Considering the limited acceptability of these nonmedical strategies, the prospects for prevention are less than what has been promised. Despite its perfections, medical care can contribute to the prevention of early death and disability. Attempts to disparage it could delay the adoption of the changes needed to improve its effectiveness.

Activities of Daily Living↗
PubMed1978

A disorder of biogenic amines in dihydropteridine reductase deficiency.

A severe deficiency of dihydropteridine reductase (DHPR) in liver, brain, and cultured skin fibroblasts was demonstrated in a child with hyperphenylalaninemia and an atypical form of phenylketonuria. DHPR is required for regeneration of the cofactor, tetrahydrobiopterin. The cofactor is essential in hydroxylation of aromatic amino acid precursors in the biosynthesis of neurotransmitters, serotonin, dopamine, and norepinephrine. In gray tissue at brain biopsy, dopamine was low at 3 ng per gram of tissue, serotonin was barely detected, and norepinephrine appeared high at 1600 ng per gram. In cerebrospinal fluid, homovanillic acid (HVA) was low normal at 33 ng/ml, 5-hydroxyindoleacetic acid (5-HIAA) was low at 4.2 ng/ml, and after a high dose of oral probenecid there was impaired accumulation of HVA to 128 ng/ml and 5-HIAA to 22.4 ng/ml. When the patient was 22 months of age, treatment with hydroxylated aromatic amino acid precursors was initiated, and after three months HVA and 5-HIAA levels were increased in CSF. The apparent restoration of biogenic amines in brain appears to have delayed the rate of neurological deterioration. DHPR activity in cultured skin fibroblasts of children with persistent hyperphenylalaninemia should permit early diagnosis and early treatment of this disorder.

5-Hydroxytryptophan↗
PubMed1977

Anatomy of a trial.

Explore the source record for details and available documents.

Child, Preschool↗
PubMed1976

Attachment of thioglycosides to proteins: enhancement of liver membrane binding.

Thioglycosides of D-galactose, D-glucose, N-acetyl-D-glucosamine, and D-mannose were covalently attached to Aspergillus oryzae alpha-amylase, hen's eggs lysozyme, and bovine serum albumin by amidination, diazo coupling, and amide formation. The binding of the newly formed glycoproteins (neoglycoproteins) to rabbit liver membranes was measured, using asialoorosomucoid as a reference. Attachment of D-galactosides by any of the three methods enhanced binding by several orders of magnitude. Coupling of a comparable number of D-mannosides or N-acetyl-D-glucosaminides had little or no effect. Attachment of D-glucosides also enhanced binding but to a variable extent depending on the method of attachment. Thus, the behavior of neoglycoproteins toward rabbit liver membranes closely paralleled that of serum glycoproteins (Ashwell and Morell, 1974) with respect to sugar specificity.

Acetylglucosamine↗
PubMed1976

Hyperphenylalaninemia due to dihydropteridine reductase deficiency. Assay of the enzyme in fibroblasts from affected infants, heterozygotes, and in normal amniotic fluid cells.

Two infant siblings with modest elevations of serum phenylalanine concentrations had seizures and developmental regression: they died in their second year. Dihydropteridine reductase activity, which can be measured in normal cultured skin fibroblasts, was measured in the younger sibling and was absent. Parents of the two siblings and parents of a previously reported patient all showed 50% or less of the normal dihydropteridine reductase activity in their cultured fibroblasts. Dihydropteridine reductase activity is also present in normal cultured amniotic fluid cells, offering the possibility of prenatal diagnosis. Absence of dihydropteridine reductase results not only in a defect in the conversion of phenylalaning to tyrosine, but also in the biosynthesis of the neurotransmitters, dopamine, norephinephrine, and serotonin. Since deficiencies in these neurotransmitters would not be alleviated by a phenylalanine-restricted diet, it is important to establish the nature of the enzymatic defect in all suspected variants of phenylketonuria.

Adult↗