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Biomedical subjects

R J Allen

Publications and source records attributed to R J Allen.

At least 55 records · Page 3Linked to original sources
PubMed1983

Kearns-Sayre syndrome with reduced plasma and cerebrospinal fluid folate.

A young woman with Kearns-Sayre syndrome and progressive central nervous system deterioration over 15 years had decreased plasma and cerebrospinal fluid folate levels while receiving phenytoin for a seizure disorder. A muscle biopsy showed a "ragged red fiber" myopathy with reduced muscle carnitine and mitochondrial enzymes. Computed tomographic brain scans showed cerebral white matter hypodensities and bilateral calcification of the basal ganglia. The mechanism for the folate deficiency and altered ratio of plasma to cerebrospinal fluid folate is unknown, but the deficiency may be responsive to replacement therapy.

Adolescent↗
PubMed1983

Phenotypic variation in biotinidase deficiency.

Biotinidase deficiency is the usual biochemical defect in biotin-responsive late-onset multiple carboxylase deficiency. We reviewed the clinical features of six patients with the enzyme deficiency and compared them with features described in the literature in children with late-onset MCD. In all of the reported probands, MCD was diagnosed because they had metabolic ketoacidosis and organic aciduria in addition to various neurologic and cutaneous symptoms, such as seizures, ataxia, skin rash, and alopecia. Although in several of our patients biotinidase deficiency was also diagnosed because they manifested a similar spectrum of findings, others never had ketoacidosis or organic aciduria. Thus the initial features of biotinidase deficiency usually include neurologic or cutaneous symptoms, whereas organic aciduria and MCD are delayed, secondary manifestations of the disease. These findings suggest that biotinidase deficiency should be considered in any infant or child with any of these neurologic or cutaneous findings, with or without ketoacidosis or organic aciduria. If the diagnosis cannot be excluded, such individuals should be given a therapeutic trial of pharmacologic doses of biotin.

Amidohydrolases↗
PubMed1983

Capsular stroke as a cause of hemiplegia in infancy.

Small, deep lesions of the internal capsule are an uncommon cause of infantile hemiplegia. We report the clinical and radiographic findings of three children with hemiplegia with capsular lesions. Although the etiology of capsular stroke in these children remains uncertain, neither hypertension, coagulopathy, nor vascular malformation was an important factor.

Cerebrovascular Disorders↗
PubMed1983

Newborn screening for phenylketonuria: predictive validity as a function of age.

Data from questionnaires were assembled for 109 infants with phenylketonuria (PKU) and 114 control infants to assess the predictive validity of newborn screening for PKU as a function of age. Patients with PKU had values of less than 4 mg/dL in cord blood and in samples from days 1, 2, and 4 through 7. The proportion of patients with PKU expected to fall below screening cutoffs of 2, 4, and 6 mg/dL was predicted for each age range. Using a cutoff of 4 mg/dL, approximately one third of patients with PKU would be missed by a sample taken from the neonate in the first 12 hours of life, and nearly 10% would be missed with a sample from the second 12 hours of life. This study shows that not all patients with PKU will be detected by newborn screening, and that the phenomenon of early nursery discharges must be considered in developing appropriate screening strategies.

Age Factors↗
PubMed1982

Neurotrichosis: hair-shaft abnormalities associated with neurological diseases.

Six children with morphological hair-shaft abnormalities and neurological disease are presented, including two with Pollitt syndrome, one with biotin deficiency, two with Menkes diseases and one with argininosuccinic aciduria. The child with biotin deficiency grew normal hair following oral biotin therapy. Although the hair-shaft abnormalities may be seen with light microscopy (LM), they are best visualised with scanning electron-microscopy (SEM). Pili torti may be mistaken for monilethrix by LM, but SEM shows the true defect. A review of the literature shows that these hair-shaft abnormalities (trichorrhexis nodosa, monilethrix and pili torti) are not specific or pathognomonic, but do indicate a group of neurological disorders, including potentially treatable inborn errors of metabolism. The term 'neurotrichosis' is suggested to classify this group of disorders.

Adult↗
PubMed1981

Abrupt neurological deterioration in children with Kearns-Sayre syndrome.

The conditions of a young woman and a boy with Kearns-Sayre syndrome (KSS) deteriorated abruptly; they died despite pacemaker control of complete heart block (case 1) and without evidence of arrhythmia or asystole. Extensive spongy vacuolization of the brainstem was shown by serial computerized tomographic scanning (case 2) and at autopsy (case 1). A review of the literature indicated that KSS in childhood is particularly severe and is associated with diffuse, progressive, spongy degeneration of the brain. Children with KSS have clinical, roentgenographic, and neuropathological evidence of spongy degeneration of the brain, which may be related to abrupt deterioration and death despite adequate control of heart block. Periodic brainstem auditory evoked response studies may allow early recognition of this process.

Adolescent↗
PubMed1981

Human serum complement requirements for bacterial killing and protoplast lysis of Escherichia coli ML308 225.

Normal human serum kills Escherichia coli ML308 225 and lyses protoplasts derived from this organism. Human serum which is depleted of complement component C9 or deficient in component C8 is not bactericidal, but C9-depleted serum will lyse protoplasts whereas C8-deficient serum will not. Bacterial lipopolysaccharide, which can protect bacteria from the serum bactericidal reaction, does not protect protoplasts from lysis by serum.

Bacteriolysis↗
PubMed1981

Nutrition and the work of the Codex Alimentarius Commission.

Nutritional and dietary aspects are central to the work of the Codex Alimentarius Commission on foods special dietary uses and on nutrition labelling, and are playing a major part in the development of standards such as those for cereals and vegetable proteins. In the general work of the Commission and its subsidiary bodies many draft and existing standards either contain specific nutritional provisions or individually or collectively help to protect the nutritional quality of the food supply by controlling the composition and description of foods passing in trade. Work now in courses and planning by the Commission will increase the commitment to nutrition in the Codex programme.

Dietary Services↗