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Biomedical subjects

R A Price

Publications and source records attributed to R A Price.

At least 109 records · Page 6Linked to original sources
PubMed1987

Genetic contributions to human fatness: an adoption study.

A strong relationship was found between the degree of fatness of biologic mothers and that of their adult offspring who had been separated from their mothers at birth and adopted during the first year of life. This relationship persisted even after age, height, and possible confounding environmental factors were controlled. There was little evidence for either selective placement on the basis of parental fatness or gene-environment interaction. There was no relationship between the degree of fatness of adoptive parents and that of the adoptees. Two indexes of environmental influence--rural upbringing and disturbance in the adoptive home--predicted fatness among adoptees.

Adipose Tissue↗
PubMed1986

Gilles de la Tourette's syndrome: tics and central nervous system stimulants in twins and nontwins.

Thirty-four of 170 surveyed individuals with Tourette's syndrome (TS) were treated with CNS stimulants before age 18. In 24% of treated individuals, persistent exacerbation of tics was closely associated with treatment. In 3%, tic response was transient, and in 24%, tics were not obviously associated with treatment. Six pairs of monozygotic twins were discordant for stimulant treatment, and all untreated co-twins also developed TS. The number of individuals in whom stimulants permanently exacerbate tics may be small, but the risk appears to be real. Genetic vulnerability and duration and timing of treatment may mediate response.

Antipsychotic Agents↗
PubMed1986

Prognostic factors in pediatric brain-stem gliomas.

The clinical, computerized tomography (CT), and histological findings from 84 children with brain-stem gliomas were reviewed to determine whether any of these features correlated with outcome. Clinical data were available from all children, CT data from 62 children, and biopsy data from 54 children. Actuarial life tables were constructed for each clinical, CT, and histological feature and the differences between these were analyzed. The period of survival was significantly shorter in children who presented with cranial nerve palsies (p less than 0.0001), and such children were more likely to have malignant tumors. Two CT features correlated with a significantly decreased survival time: a hypodense tumor prior to contrast administration and a tumor that involved the entire brain stem. Tumor enhancement was not associated with any alteration in survival times. Children with tumor biopsies that were histologically benign survived significantly longer than those whose tumors were malignant (p less than 0.0001). The histological feature associated with the poorest survival time was the presence of mitoses; features associated with the best prognosis were Rosenthal fibers and calcification. The data indicate that brain-stem gliomas are not a homogeneous group of tumors as far as their clinical, CT, and pathological features are concerned. These features may be useful in assessing prognosis and in developing future treatment protocols.

Brain Neoplasms↗
PubMed1986

Effects of high pressure on platelet aggregation in vitro.

An apparatus which enables aggregating agents to be added to a stirred suspension of platelets subjected to a pressure of up to 600 ATA is described. The ensuing aggregation reaction is monitored optically. The pressure is applied with helium; data are presented that indicate the effects are mainly attributable to hydrostatic pressure. The aggregation of human platelets induced by ADP was reversibly inhibited by pressure in the 1-270 ATA range. The second phase of aggregation was blocked by 65 ATA; the rate of first phase aggregation was reduced but the time to respond to ADP was not affected. Comparable pressures also affected collagen and arachidonate-induced aggregation. The time to respond to these aggregating agents was prolonged and both the rate and the degree of aggregation were reduced by pressure.

Adenosine Diphosphate↗
PubMed1985

Diencephalic gliomas of children. A clinicopathologic study.

The authors reviewed the clinical information and pathology specimens from 29 children with diencephalic gliomas to determine whether any clinical or histopathologic feature correlated with prognosis. The median survival time for the entire group was 3.96 years. No symptom or sign at the time of diagnosis correlated with outcome. The tumors consisted of 25 astrocytomas or mixed gliomas and 4 malignant astrocytomas-mixed gliomas. Median survival time of the 25 children with astrocytomas-mixed gliomas was 4.8 years, compared with 0.5 years for the 4 children with malignant tumors. The tumor histology was relatively uniform: most tumors were moderately cellular astrocytomas with pleomorphism and hyperchromatism but without mitoses, hemorrhage, or necrosis. High cell density and the presence of mitoses were the two histologic features significantly associated with poor prognosis; no child with mitosis survived longer than 14 months.

Actuarial Analysis↗
PubMed1985

A twin study of Tourette syndrome.

In 43 pairs of same-sex twins, in which at least one co-twin had Tourette syndrome (TS), 30 pairs were probably monozygotic (MZ) and 13 were probably dizygotic (DZ). Concordances for TS were 53% and 8% for MZ and DZ pairs, respectively. When diagnostic criteria were broadened to include any tics in co-twins, concordance rates were 77% and 23% for MZ and DZ pairs, respectively. These concordances are consistent with genetic etiology. However, the fact that only 53% of MZ twins were fully concordant indicates nongenetic factors affect expression of TS. Presence of tics in discordant co-twins and timing of onset in partially concordant co-twins support an association between TS and tics in families with TS present. The data are inconclusive on whether some MZ twins with discordant co-twins are etiologically different from those who are concordant.

Adolescent↗
PubMed1985

Ascending myelopathy after chemotherapy for central nervous system acute lymphoblastic leukemia: correlation with cerebrospinal fluid myelin basic protein.

Ascending myelopathy developed in a previously irradiated 10-year-old boy after intraventricular methotrexate and cytosine arabinoside were given for central nervous system relapse of acute lymphoblastic leukemia. The course was fatal in 10 weeks. Cerebrospinal fluid myelin basic protein levels, indicating a demyelinative process, rose prior to the onset of clinical symptoms and remained at very high levels until death. Myelin basic protein may be useful as a predictor of chemotherapy-associated neurotoxicity.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1985

Multiple threshold models for the affective disorders: the Yale-NIMH collaborative family study.

From the Yale-NIMH collaborative family study, the 1482 first degree relatives of 90 bipolar 1, and 163 major depression probands were examined to test the hypothesis that bipolar 1 and major depression are due to a single underlying genetic liability. We attempted to fit multifactorial-polygenic and single-major-locus multiple threshold models for sex and severity to the relatives in the major depression and bipolar 1 families. With relatives classified as affected only if they met criteria for major depression or bipolar 1, there was at best only marginal support for these models. Differences between these and previously reported results were examined in relation to differences in underlying assumptions. Additional analyses of these and other data from families of NIMH bipolar 2 and schizoaffective probands suggest that different methods of age adjustment, the relative placement of bipolar 2 and schizoaffective disorders in a hypothesized liability continuum and the inclusion or exclusion of sex thresholds were not primarily responsible for differences in the fit of genetic threshold models. Factors which do appear to be important are variability in rates between samples, the possibility of genetic heterogeneity, and the presence of a large secular increase in affective illness over the past three generations; the secular trend cannot be accommodated in the models of genetic transmission examined.

Adult↗
PubMed1984

Treatment of sexual precocity by removal of a luteinizing hormone-releasing hormone secreting hamartoma.

A 1-year-old infant was initially seen with precocious puberty that progressed rapidly and was associated with episodic gonadotropin release. A computed tomographic metrizamide cisternogram showed a pedunculated mass below the tuber cinereum; the mass was resected. His pubertal development regressed, his accelerated growth ceased, and his hormone levels returned to the normal prepubertal range. Immunocytochemical studies of the tissue demonstrated luteinizing hormone-releasing hormone (LHRH) granules in the perikaryon of neurons and axons in the hamartoma and axons connecting the hamartoma to the tuber cinereum. These data suggest that such lesions cause pubertal development by stimulating gonadotropin secretion via episodic release of LHRH. If such lesions are pedunculated, operative resection may be the treatment of choice.

Gonadotropin-Releasing Hormone↗
PubMed1984

Utilizing automated methods to improve estimates of recurrence risk with linked genetic markers.

Information on linked markers can greatly improve estimates of recurrence risk for genetic disorders. However, when linkage is incomplete, utilizing the information in genetic counseling requires complex, repetitive calculations to estimate correct risks whenever the parental linkage phase is not precisely known. This paper demonstrates with examples how the computer program LIPED can be used for any pedigree to estimate risk precisely within bounds determined only by confidence limits on the recombination fraction.

Adult↗
PubMed1983

Brain stem gliomas of children. A clinicopathological study.

To determine the risks and benefits of biopsying brain stem gliomas of children, the authors analyzed the clinical and histopathological features of 27 children with biopsied brain stem gliomas and compared them to 26 children with brain stem gliomas that were not biopsied. In both groups, cranial nerve palsies at the time of diagnosis were associated with increased mortality. There was no operative mortality and low operative morbidity associated with biopsies, and 35% of the biopsied children survived 5 years or longer. Children with exophytic tumors and those who received more than 4000 rad survived significantly longer. When the histologic features of pleomorphism, nuclear hyperchromatism, and mitoses were present, they occurred uniformly throughout each biopsy, regardless of the sample size. Mitoses in the biopsy specimen were associated with significantly increased mortality. The authors conclude that the risk of biopsying brain stem gliomas in children is low, and that the benefit is the identification of those children who should be treated more intensively because of their poor prognosis.

Adolescent↗
PubMed1983

Childhood oligodendrogliomas presenting with seizures and low-density lesions on computed tomography.

Three children with cerebral oligodendrogliomas causing partial complex or generalized seizures presented with completely normal neurologic examinations. CT showed low-density, nonenhancing surface lesions. Although these CT features are usually associated with infarcts or cysts, neoplasm was suspected because of irregularity of the margins and erosion of the adjacent inner table of the skull. Oligodendrogliomas often enlarge slowly and may cause seizures years before they produce focal neurologic signs. CT of all children with seizures not responsive to anticonvulsant medication and focal clinical or EEG abnormalities will hasten diagnosis of slowly growing intracranial mass lesions.

Brain Neoplasms↗
PubMed1983

Posterior dural arteriovenous malformations in infancy.

A 23-month-old infant with an extensive dural arteriovenous malformation (AVM) developed a heart murmur and cardiomegaly. The AVM involved the occipital and suboccipital dura mater and the tentorium, bilaterally. We embolized the AVM with Gelfoam and polyvinyl alcohol particulates, subtotally resected it, and embolized residual vessels with isobutyl cyanoacrylate. In spite of this extensive therapy, the malformation was not totally eradicated and an occipital pial AVM developed. This infant and the eight infants with posterior dural AVMs reported previously emphasize the difficulty of eradicating these lesions in infancy. We contrast the clinical features and therapy of infants and adults with posterior dural AVMs. Infants develop heart failure and cranial bruits because of arteriovenous shunts, whereas adults complain of headache and intracranial bruits. Infants need therapy to prevent progressive heart failure, intracranial hypertension, and perhaps cerebral ischemia. Ligation of arterial tributaries is inadequate therapy for these lesions. Embolization and resection of the malformation, when feasible, offers the best chance of curing posterior dural AVMs with extensive arterial tributaries.

Dura Mater↗
PubMed1981

Normal computed tomograms of the brain in osteosarcoma patients treated with high-dose methotrexate.

Eighteen patients with osteosarcoma, most of whom were adolescents, were examined for abnormalities of the brain by use of computed axial tomography. These studies were performed at 15-60 months (median 47 months) after the completion of adjuvant chemotherapy, which included high-dose methotrexate, cyclophosphamide, and Adriamycin. No abnormalities were found. The results of this study, together with the absence of brain lesions in published reports in children receiving high-dose methotrexate but no cranial irradiation, indicate that delayed neurotoxicity is not a major complication of this form of therapy in older children.

Adolescent↗
PubMed1981

Progression of methotrexate-induced leukoencephalopathy in children with leukemia.

From 1972-1974, 228 children began treatment for acute lymphocytic leukemia and were prospectively assessed for neurologic complications. After CNS irradiation (2,400 rad) and intrathecal methotrexate (MTX), they received weekly intravenous maintenance therapy with MTX alone (40-60 mg/m2; 20 patients) or MTX (10-30 mg/m2) with other drugs (208 patients). Signs of leukoencephalopathy appeared in 11 children (nine without CNS leukemia) after 4-15 months of IV MTX alone, and included lethargy, seizures, spasticity, paresis, drooling, and dementia. Before or during the clinical onset, EEG frequencies slowed (all ten patients tested). Radionuclide scans showed periventricular accumulation of 99mTc (9/11 patients) and remained abnormal for greater than or equal to six months in eight patients. Cranial computed tomograms or neuropathology findings (five patients each) demonstrated leukoencephalopathy (nine patients) and radiation-related microangiopathy (ten patients). Severe neurologic and neuropsychologic dysfunctions were present in four long-term survivors.

Brain↗