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Biomedical subjects

J Miser

Publications and source records attributed to J Miser.

27 records · Page 2Linked to original sources

Evaluation of growth hormone release and human growth hormone treatment in children with cranial irradiation-associated short stature.

We studied nine children who had received cranial irradiation for various malignancies and subsequently experienced decreased growth velocity. Their response to standard growth hormone stimulation and release tests were compared with that in seven children with classic GH deficiency and in 24 short normal control subjects. With arginine and L-dopa stimulation, six of nine patients who received radiation had a normal GH response (greater than 7 ng/ml), whereas by design none of the GH deficient and all of the normal children had a positive response. Only two of nine patients had a normal response to insulin hypoglycemia, with no significant differences in the mean maximal response of the radiation and the GH-deficient groups. Pulsatile secretion was not significantly different in the radiation and GH-deficient groups, but was different in the radiation and normal groups. All subjects in the GH-deficient and radiation groups were given human growth hormone for 1 year. Growth velocity increased in all, with no significant difference in the response of the two groups when comparing the z scores for growth velocity of each subject's bone age. We recommend a 6-month trial of hGH in children who have had cranial radiation and are in prolonged remission with a decreased growth velocity, as there is no completely reliable combination of GH stimulation or release tests to determine their response.

Adolescent↗

Cytosine arabinoside cerebrospinal fluid kinetics.

To better characterize the disposition of cytosine arabinoside (Ara-C) in cerebrospinal fluid (CSF), its kinetics were studied in seven patients with meningeal leukemia in complete remission. After intraventricular injection of 30 mg Ara-C, CSF and plasma samples were obtained over a 24-hr period. Ara-C levels were measured by a reverse-phase HPLC assay (with a sensitivity of 0.5 microM in CSF and 1.0 microM in plasma) that readily separated Ara-C from its major metabolite uracil arabinoside (Ara-U). Elimination of Ara-C from CSF followed a biphasic pattern, with an initial t1/2 of 1 hr and a terminal t1/2 of 3.4 hr. Ara-C clearance from CSF was 0.42 ml/min, suggesting that drug elimination was primarily by CSF bulk flow. The ratio of the AUC of Ara-U to the AUC of Ara-C was 0.08, indicating only minor metabolism of Ara-C to Ara-U in CSF, in contrast to that after systemic Ara-C. Despite initial CSF Ara-C concentrations exceeding 2 mM, Ara-C was not detectable in plasma in any patient. Intraventricular Ara-C results in very high levels in CSF, but systemic tissues are relatively spared from exposure to Ara-C.

Adolescent↗

Blue Rubber Bleb Nevi as a cause of intussusception.

The Blue Rubber Bleb Nevus syndrome is a rare disease characterized by a distinctive type of hemangioma which involves the skin and the gastrointestinal tract. In the latter location, these lesions are often responsible for chronic blood loss and secondary anemia, and in rare situations may act as a leading point for an intussusception. The diagnosis of intussusception in children older than 3 or 4 yr is frequently difficult and delayed. In a child with typical skin lesions of the Blue Rubber Bleb Nevus syndrome, an acute illness with manifestations of intestinal obstruction should indicate the possibility of an associated intussusception.

Child↗

Pulmonary valvulotomy in Factor XI deficiency.

This is the first reported case in the English literature of Factor XI deficiency in a child from India. He underwent open-heart surgery and pulmonary valvulotomy without excessive or delayed hemorrhage using plasma infusion to sustain Factor XI levels at about 40% of normal before, and for 10 days after surgery. The management of this child is presented as an approach to patients with Factor XI deficiency who require major surgery.

Child, Preschool↗

Clinical pharmacology of 9-beta-D-arabinofuranosyladenine in combination with 2'-deoxycoformycin.

It has been suggested that, by inhibiting the adenosine deaminase (ADA)-mediated catabolism of 9-beta-D-arabinofuranosyladenine (ara-A), 2'-deoxycoformycin (DCF) would increase the half-life (t1/2) of ara-A, a compound with known antileukemic activity. To test this hypothesis, we collected serial plasma samples from five patients with refractory acute lymphoblastic leukemia who participated in a Phase I trial of i.v. DCF 915 mg/sq m) in combination with i.v. single-dose ara-A (120-250 mg/sq m). In four of these patients, of whom three were known to have achieved greater than 98% ADA inhibition, a mean ara-A t1/2 of 227 min was achieved. Extrapolated peak levels (i.e., following infusion of ara-A) ranged from 1.5 to 7.4 micrograms/ml (mean, 4.2 micrograms/ml). Elimination of drug appeared to follow a single-compartment model. In two patients who received ara-A without prior DCF and in a third patient who had significant residual ADA activity despite DCF, ara-A was unmeasurable within 5 min of the end of infusion. These data confirm that the kinetics of ara-A catabolism can be altered by inhibition of ADA and suggest that more than one dose of DCF may be necessary for complete inhibition of the enzyme and optimal pharmacological modulation of ara-A.

Adolescent↗

Immune response after splenectomy.

The immune response to intravenously administered bacteriophage phiX 174 and subcutaneously administered tridecavalent pneumococcal polysaccharide vaccine was studied in 31 patients with anatomical or functional asplenia. Antibody responses to primary immunisation with phiX 174 were significantly decreased while clearance was normal. Secondary responses were quantitatively normal; however, production of antibody did not switch from IgM to IgG as seen in controls. All groups of asplenic patients accept those patients with Hodgkin's disease demonstrated significant seroconversions in response to pneumococcal polysaccharide antigens. One patient with Hodgkin's disease, treated with local irradiation only, demonstrated normal responses to pneumococcal capsular antigens. 10 of the 12 capsular antigens for which antibody was measured stimulated threefold increases in antibody in the 26 asplenic patients without Hodgkin's disease, which is similar to that observed in controls. Since the majority of cases of overwhelming postsplenectomy infection are caused by Streptococcus pneumoniae, all patients with either anatomical or functional asplenia should receive pneumococcal polysaccharide vaccine.

Adolescent↗

Solitary maxillary central incisor and short stature.

Seven patients, three males and four females, each with a single (unpaired) deciduous and permanent maxillary central incisor, were studied. All the males and two the female children were growth hormone deficient. One adult woman and a female infant with a single maxillary central incisor were short in stature but had normal growth hormone responses. No other dental anomalies or pituitary-hypothalamic dysfunctions were found. The dental anomaly was not familial. No eye abnormalitis were present in the patients or their families.

Adult↗