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Biomedical subjects

S Pierce

Publications and source records attributed to S Pierce.

12 recordsLinked to original sources
PubMed1992

Prognostic significance of elevated serum beta 2-microglobulin levels in adult acute lymphocytic leukemia.

PURPOSE: Elevated serum beta-2 microglobulin (beta 2M) levels are associated with poor prognosis in several lymphoproliferative disorders including multiple myeloma and lymphoma. Their prognostic relevance in acute lymphocytic leukemia (ALL) is unknown. We analyzed the associations of serum beta 2M levels at diagnosis with pretreatment characteristics and with prognosis in adult ALL. PATIENTS AND METHODS: One hundred fifty-nine adults with newly diagnosed ALL were investigated. Serum beta 2M levels were determined at diagnosis, on fresh peripheral blood samples, using a radioimmunoassay, the Pharmacia beta 2 Micro RIA (Pharmacia Diagnostics, Uppsala, Sweden). Statistical correlations were assessed by standard methods, and further independent prognostic value of serum beta 2M was determined by multivariate analysis. RESULTS: Patients with beta 2M levels of 4.0 mg/L or above had a lower complete response rate (61% versus 80%; p = 0.02), a significantly worse survival (p < 0.01), and a significantly higher association with development of central nervous system (CNS) leukemia (p < 0.01). High beta 2M levels were more common among patients with older age, with elevated creatinine, bilirubin, and alkaline phosphatase levels, with low albumin levels, and with B-cell disease. Multivariate analysis for survival indicated the beta 2M level to be an independent prognostic variable (after adjusting for pretreatment creatinine level and age). The evaluation of beta 2M levels within low- and high-risk groups for CNS disease suggested an association of elevated beta 2M levels with a worse incidence of CNS disease in the high-risk patients. CONCLUSION: Monitoring serum beta 2M levels may provide significant prognostic information in adults with ALL and should be included in their pretreatment evaluation. Its importance in childhood ALL requires investigation.

Adult↗
PubMed1992

Treatment of advanced stages of Philadelphia chromosome-positive chronic myelogenous leukemia with interferon-alpha and low-dose cytarabine.

PURPOSE: To evaluate the efficacy of interferon-alpha (IFN-A) and low-dose cytarabine (ara-C) combination chemotherapy in patients with chronic myelogenous leukemia (CML). PATIENTS AND METHODS: Sixty patients with advanced phases of Philadelphia chromosome (Ph)-positive CML received combination therapy with IFN-A 5 x 10(6) U/m2 daily, and low-dose ara-C 15 mg/m2 daily for 2 weeks every 4 weeks until remission, then for 1 week every month as maintenance. Forty patients were in late chronic-phase CML, and 20 were in accelerated-phase CML (16 with clonal evolution only, four with other criteria). Their outcome was compared with 58 patients (39 late chronic-phase CML and 19 accelerated-phase CML) who had been previously treated with IFN-A alone in the same dose schedule. RESULTS: In late chronic-phase CML, patients receiving IFN-A plus ara-C had a better complete hematologic response (CHR) rate compared with those treated with IFN-A alone (55% v 28%; P = .02), a trend for better Ph suppression (15% v 5%; P = .13), and a longer survival (3-year survival rate 75% v 48%; P less than .01). These differences do not seem to be caused by imbalances in prognostic factors between the two treatment groups. In accelerated-phase CML, the addition of ara-C to IFN-A did not improve the response rate of treated patients, and the difference in survival was accounted for by different patient characteristics. Suppression of clonal evolution was observed in five patients (25%). Patients with clonal evolution as the only criterion for disease acceleration had a longer survival than those with other or additional accelerated-phase criteria (3-year survival rate 67% v 22%; P less than .01). CONCLUSION: The results with the combination of IFN-A plus ara-C in late chronic-phase CML are encouraging, and suggest the need for its evaluation in early chronic-phase CML.

Adult↗
PubMed1991

Cochlear-nucleus branches of thick (medial) olivocochlear fibers in the mouse: a cochleotopic projection.

Olivocochlear neurons have somata in the superior olivary complex and provide an efferent innervation to the cochlea. One subgroup of olivocochlear neurons, medial olivocochlear neurons, sends fibers to innervate the cochlear outer hair cells. En route to the cochlea, medial olivocochlear fibers give off branches to the ventral cochlear nucleus, the first auditory center of the brain. This study examines the cochlear-nucleus branches of medial olivocochlear fibers, comparing those from fibers that innervate the cochlear base with those from fibers that innervate the cochlear apex. Basal fibers give off dorsal branches to the granule cell lamina and ventral branches to the auditory nerve root. Apical fibers give off few dorsal branches but many ventral branches that terminate rostrally to the nerve root. This cochleotopic mapping of medial olivocochlear branches corresponds in a general way to that of afferent fibers. Unlike afferent fibers, however, the branches terminate primarily along the edges of the cochlear nucleus. In the mouse, the particular edges of termination are (1) the medial border of the ventral cochlear nucleus where it meets the underlying vestibular nerve root, and (2) the border between the ventral cochlear nucleus and the granule cell lamina. Neurons and dendrites of these border regions may thus integrate efferent and afferent information in a frequency-specific manner.

Afferent Pathways↗
PubMed1990

Afferent and efferent innervation of the cat cochlea: quantitative analysis with light and electron microscopy.

The purpose of the present study was to describe the longitudinal and radial gradients of cochlear innervation in the cat. To this end, afferent and efferent terminals of both the inner (IHC) and outer hair cell (OHC) regions were reconstructed from serial ultrathin sections at six and eight cochlear locations, respectively, corresponding to roughly octave intervals of characteristic frequency (CF). Analysis of the afferent innervation of the IHCs showed 1) the number of radial fibers per IHC rises from 10 per IHC at the 0.25 kHz region to a maximum of 30 per IHC at the 10 kHz locus; 2) branching of radial fibers is essentially restricted to regions apical to the 1.0 kHz point; and 3) there are significant differences in synaptic-body morphology for synapses on different sides of the IHC, corresponding to known differences in afferent threshold and rate of spontaneous activity. With respect to efferent innervation in the IHC area, we found 1) that there were numerous vesicle-filled terminals contacting every IHC examined; however, those with obvious synaptic specialization were confined to the most apical regions; and 2) there were roughly the same numbers of efferent synapses per radial fiber at all cochlear locations; however, at each location, radial fibers contacting the modiolar side of the hair cell (corresponding to high-threshold afferents) showed significantly more efferent synapses than radial fibers contacting the pillar side. Analysis of the OHC afferent innervation showed 1) a clear rise in numbers of terminals per OHC from roughly 3 per cell in the base to 15 per cell in the apex, 2) no systematic differences in the numbers of terminals as a function of OHC row, and 3) that synaptic bodies at the OHC afferent synapse are common only apical to the 1.0 kHz locus. Counts of efferent terminals on OHCs revealed 1) maximal numbers (9 per OHC) between the 6 and 24 kHz regions and 2) striking decrease in terminal counts from first- to third-row OHCs. Ultrastructural data on efferent innervation were compared quantitatively with light-microscopic analysis of cochleas immunostained (with antibody to synaptophysin) to reveal all vesiculated terminals.

Afferent Pathways↗
PubMed1988

N-myc oncogene RNA expression in neuroblastoma.

Tumor specimens from 33 patients with neuroblastoma were assayed for amplification of the N-myc oncogene and RNA expression to determine whether N-myc RNA expression levels correlated with N-myc gene amplification and clinical outcome. N-myc gene amplification was detected in one stage II tumor, one stage IV-S tumor, and seven stage III or IV tumors. In each case, N-myc RNA expression roughly paralleled N-myc gene amplification. However, enhanced N-myc RNA expression was not confined to tumors with N-myc gene amplification: all of the early (stage I and II) tumors, five stage IV-S tumors, and 12 advanced (stage III and IV) tumors had levels of N-myc RNA that were elevated up to 50-fold. While N-myc gene amplification correlated with prognosis, there was no such correlation with levels of N-myc RNA expression. The precise role of the N-myc gene in the pathogenesis of neuroblastoma remains unclear.

Adolescent↗
PubMed1978

Glutathione peroxidase activities from rat liver.

There are two enzymes in rat liver with glutathione peroxidase activity when cumene hydroperoxide is used as substrate. One is the selenium-requiring glutathione peroxidase (glutathione:hydrogen-peroxide oxidoreductase, EC 1.11.1.9) and the other appears to be independent of dietary selenium. Activities of the two enzymes vary greatly among tissues and among animals. The molecular weight of the enzyme with selenium-independent glutathione peroxidase activity was estimated by gel filtration to be 35 000, and the subunit molecular weight was estimated by dodecyl sulfate-polyacrylamide gel electrophoresis to be 17 000. Double reciprocal plots of enzyme activity as a function of substrate concentration produced intersecting lines which are suggestive of a sequential reaction mechanism. The Km for glutathione was 0.20 mM and the Km for cumene hydroperoxide was 0.57 mM. The enzyme was inhibited by N-ethylmaleimide, but not by iodoacetic acid. Inhibition by cyanide was competitive with respect to glutathione and the Ki for cyanide was 0.95 mM. This selenium-independent glutathione peroxidase also catalyzes the conjugation of glutathione to 1-chloro-2,4-dinitrobenzene. Along with other similarities to glutathione S-transferase, this suggests that the selenium-independent glutathione peroxidase and glutathione S-transferase activities in rat liver are of the same enzyme.

Animals↗
PubMed1977

A syntactic investigation of verbal autistic, mentally retarded, and normal children.

The syndrome of childhood autism is typified by major abnormalities in language development, yet there are few systematic descriptions of autistic children's linguistic systems. We have, therefore, begun a comprehensive investigation of the language of verbal autistic children and concentrate in this paper on comparing the syntax used by 10 verbal autistic children matched for nonlinguistic mental age with a group of mentally retarded subjects and normal controls. Two different means of assessing syntactic development were utilized: Lee's Developmental Sentence analysis and Chomsky's Transformational analysis. The autistic group was found to rank significantly lower than either the mentally retarded or the normal groups in terms of Developmental Sentence Scores. When a transformational grammar was used to describe the language samples of our subjects the autistic children were typified by a higher error rate and lower level of complexity compared to the other two groups. However, the results also indicate that the grammatical system of autistic children is rule-governed and probably not unlike that of young normal or retarded children. In conclusion, it appears that the syntactic abnormalities characteristic of autism are attributable to an extreme delay in language development as well as to an impaired ability to make use of linguistic rules.

Autistic Disorder↗
PubMed1977

Effects of selenite and selenomethionine on glutathione peroxidase in the rat.

The activity of glutathione (GSH) peroxidase (EC 1.11.1.9) decreased in tissues of rats fed a diet deficient in selenium. A single dose of 300 mug selenium by stomach tube increased GSH peroxidase activity within 48 hours. The effects of selenite and selenomethionine on GSH peroxidase activity were roughly similar. This study provides evidence that selenium from both selenite and selenomethionine is readily available for synthesis of the selenoenzyme GSH peroxidase in rat tissues.

Animals↗
PubMed1976

Phonological investigation of verbal autistic and mentally retarded subjects.

A review of the pertinent literature indicates that autistic children are likely to show normal but delayed development of speech sounds. In contrast, atypical phonological development is suggested by experiments demonstrating that autistic subjects are deficient in their ability to extract the components of structured auditory input. A systematic investigation of the speech sound systems of verbal autistic and mentally retarded children reveals a delay in phoneme acquisition, as well as a relative uniformity of error types in both groups. The autistic subjects, however, differ significantly from the mentally retarded in the phonemic substitutions which they make. Autistic subjects are also characterized by a high correlation between frequency of phonological errors and level of overall language development. The findings are interpreted as supporting the hypothesis that the autistic group shows a more global delay in language development.

Adolescent↗
PubMed1975

A serum haemagglutinating property dependent upon polycarboxyl groups.

A serum agglutinin reactive with red cells in the presence of polycarboxyl groups is reported. It is likely that this represents an additional example of the type of agglutinin previously described as agglutinating red cells in the absence of ionized calcium. Experimental evidence is presented indicating that it is free polycarboxyl groups that potentiate agglutination and that any metal ion, such as calcium, capable of chelating with these groups will prove to be inhibitory.

ABO Blood-Group System↗