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Biomedical subjects

A M Nelson

Publications and source records attributed to A M Nelson.

85 records · Page 5Linked to original sources
PubMedDate not supplied

Urinary sialic acid screening in neurologic disorders.

Urine sialic acid was measured in 246 patients evaluated for possible neurodegenerative disorders. Total, free, and bound sialic acid excretion declined significantly with patients' ages. Among 11 patients (4.5%) with age-related excretion rates greater than 2 standard deviations above the mean, 5 had the following disorders: free sialic acid storage disease, mucolipidosis type II, pseudohypoparathyroidism, sinus histiocytosis, and probable Sanfilippo syndrome. Although the remaining 6 were undiagnosed, 2 exhibited deteriorating courses and the other 4 presented variable combinations of organomegaly, developmental delay or mental retardation, seizures, facial dysmorphism, or bony abnormalities. Thus, these individuals also may have metabolic disorders with abnormal excretions of sialic acid-containing compounds. With awareness of age-related excretion rates, sialic acid screening is most useful for the sialidoses, mucolipidoses, and disorders of free sialic acid metabolism.

Adolescent↗
PubMedDate not supplied

Infantile free sialuria without lysosomal storage.

Except for two reported patients, increased free sialic acid excretion has been associated with lysosomal storage. This is a report of a child with progressive neurologic deterioration and increased excretion of free sialic acid. Although lysosomal storage was absent, nuclear invagination or inclusions were present.

Biopsy↗
PubMedDate not supplied

Suitability of a new turbine spirometer for epidemiological surveys in children.

The performance of a new turbine spirometer, which has several advantages over equipment previously used to measure lung function, was compared with that of a conventional spirometer (Vitalograph) in a cross-over trial on 368 children six to 11 years old. On average, slightly higher values of forced expiratory volume at 0.75 s and forced vital capacity were recorded on the turbine spirometer. These differences occurred mainly in children aged less than eight years. Assuming the Vitalograph remained accurate, there appeared to be a slight tendency for readings on the turbine spirometer to drift downwards at a rate of 0.04 1 per 100 children measured but this was not statistically significant (p greater than 0.10). In conclusion, the machines differed mainly in the youngest age group. Until a recording of the complete expiration curve can be made using the turbine spirometer, it is not possible to assess whether this effect of age arose because of errors in the breath manoeuvre by younger children undetectable in the turbine spirometer or because the simpler design of the spirometer makes it easier than the Vitalograph for young children to use it correctly.

Age Factors↗
PubMedDate not supplied

[Resistance of Mycobacterium tuberculosis in Mexican patients. I. Clinical features and risk factors].

OBJECTIVE: To determine the clinical manifestations associated with resistant M. tuberculosis infection and the antimicrobial resistance in isolates from Mexican patients. STUDY DESIGN: Epidemiological surveillance. PATIENTS: Tuberculosis confirmed cases. METHODS: Primary resistance: no history of treatment prior to diagnosis. The following critical concentrations (micrograms/mL) were used for susceptibility: isoniazid 0.2 and 1; rifampin 1 and 5; ethambutol 5 and 10; streptomycin 2 and 10; ethionamide 5; kanamycin 6; and para-aminosalicylic acid (PAS) 2 and 10. RESULTS: Eighty-four patients with a mean age of 44.7 years were included; 54 men (64%) and 30 women (36%); most patients were from the Mexico City metropolitan area. In 34 patients there was clinical information available, 26 presented fever and weight loss and 8 respiratory symptoms. Fifty-nine patients (70%) were infected by pan-susceptible M. tuberculosis, and 25 (30%) by a resistant isolate; 17 (68%) of them were resistant to at least two drugs, 16 (64%) to isoniazid and rifampin. The proportion of resistance was: isoniazid 24%, rifampin 19%, streptomycin 12%, ethambutol 10%, PAS 9%, etionamide 7%, and kanamycin 6%. Of 47 patients without previous treatment, eight had a resistant microorganism (17%): 9% resistant to isoniazid, 6% to rifampin, 2% to streptomycin, 6% to PAS and 6% multiresistant. Of 37 patients with history of previous treatment for tuberculosis, 17 (46%) had a resistant isolate; 44% were resistant to isoniazid, 35% to rifampin, 24% to streptomycin, 19% to ethambutol, 12% to PAS and 35% multiresistant. Of the 84 patients, four were physicians infected by a resistant isolate, and seven HIV-infected patients, one with a multiresistant isolate, and another with isoniazid resistance. CONCLUSIONS: Antimicrobial resistance among M. tuberculosis is alarmingly high in Mexico City; these results emphasize the importance of case detection and early isolation of patients.

Adolescent↗