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B Reeves

Publications and source records attributed to B Reeves.

At least 55 records · Page 3Linked to original sources

Chromosome 11q23 translocations in both infant and adult acute leukemias are detected by in situ hybridization with a yeast artificial chromosome.

The yeast artificial chromosome (YAC-13HH4), which spans a 440-kb region of DNA just distal to the CD3 locus on chromosome 11 at band q23, has been used to characterize a range of chromosomal translocations in acute leukemias from both adults and infants. In situ hybridization was performed on metaphase cells from bone marrow of 17 leukemias and two cell lines with a variety of chromosome 11q23 abnormalities. It was established that in infant leukemias the translocations t(11;19), t(4;11), and t(5;11) had occurred in the region defined by YAC 13HH4. Additionally, the translocations t(4;11), t(6;11), t(9;11), t(X;11), and t(10;11) in other leukemias were found to disrupt the same region of chromosome 11q23, although an exception was found in one t(6;11) translocation for which the breakpoint was distal to the YAC. One patient had a t(9;11) translocation in a therapy-related leukemia, suggesting that this class of etoposide-related malignancy has similar breakpoints to those occurring in de novo leukemias. An example of a lymphoma-derived translocation t(4;11) was shown to involve a deletion of the region defined by YAC 13HH4. A leukemia with a deletion on chromosome 11 (q23-q25) was also studied and it was shown that the YAC sequence was unaffected. It was concluded that, with a few exceptions, the translocations at 11q23 in a wide range of acute infant and adult leukemias occur in a common region and may result from a common underlying mechanism.

Acute Disease↗

Possible evidence for genomic imprinting in childhood acute myeloblastic leukaemia associated with monosomy for chromosome 7.

Monosomy or deletion of chromosome 7 is a frequent finding in both de novo and secondary acute myeloid leukaemia (AML) and myelodysplastic syndromes (MDS). Based on analysis of deletions of chromosome 7 in such patients, it has been suggested that there is a critical region of the chromosome lying within bands q21-q31. We have examined bone marrow and peripheral blood samples from 10 patients with MDS, AML and biphenotypic acute leukaemia who had monosomy for or rearrangement of chromosome 7, seeking evidence of non-random allele loss that might suggest the presence of imprinted genes on the chromosome. Bone marrow cells from one patient with the infant monosomy 7 syndrome had loss of maternal alleles as did two patients with biphenotypic leukaemia. Five out of five patients with MDS and both patients with de novo AML had loss of paternal alleles. One of the latter patients had a del(7) (q31q36) rather than monosomy 7. These findings suggest that imprinting of a gene(s) on chromosome 7, within the bands q31-q36, may be of importance in MDS and AML. Despite the reported increased incidence of AML amongst relatives of patients with cystic fibrosis (CF) the gene for which lies in chromosome region 7q31, none of the patients nor parents studied here appeared to be carriers of the most common gene mutation seen in patients with CF, the delta F508.

Acute Disease↗

Orthoptists reduce false-positive hospital referrals.

This paper describes changes in the pattern of new referrals of children from birth to 2 years-of-age to the Hospital Eye Service in Oxford, following the implementation of a community-based orthoptic secondary vision-screening programme. The findings show that the number of false positive referrals was reduced by a half following the introduction of the service; false-positive referrals were also discharged sooner. This paper reports the findings of this survey and the results demonstrate the cost-effectiveness of the programme compared to outpatient attendance.

Community Health Services↗

Activated N-ras controls the transformed phenotype of HT1080 human fibrosarcoma cells.

To investigate whether the activated N-ras oncogene of HT1080 human fibrosarcoma cells contributes to the expression of the transformed phenotype, we have isolated flat revertants. In two independent revertant lines, an increase in chromosomal ploidy occurred without a concomitant increase in the number of copies of the N-ras transforming allele. Immunoprecipitation confirms that the level of the mutant N-ras p21 gene product in the revertants is correspondingly lower than in HT1080. Analysis of sporadic tumors derived from the revertant cells reveals an increased dosage of the transforming allele. The revertants also retransform after transfection of cloned activated ras oncogenes. These results imply direct participation of an N-ras oncogene in maintaining the transformed phenotype of a human tumor cell line.

Alleles↗

Evidence for increased epidermal growth factor receptors in human sarcomas.

The results of an immunocytochemical study of the epidermal growth factor receptor (EGFR) in 35 human soft-tissue sarcomas, using a murine monoclonal antibody (MAb) EGF-R1, are reported. In many of the tumours staining was stronger than in the adjacent stroma, suggesting increased levels of receptor. Particularly strong staining was seen in one epithelioid sarcoma and in the spindle-cell component of a synovial sarcoma. Binding studies carried out on an epithelioid sarcoma cell line established from one of the specimens, using radiolabelled EGF, showed that approximately 8% of the receptors were of high affinity with a dissociation constant (KD) of approximately 10(-10)M, while the remainder were of lower affinity with a KD of 10(-9)M. The cells expressed a total of 1.7 X 10(6) receptors/cell which is equivalent to that found in some epidermoid tumours where gene amplification has been demonstrated. These data suggest that, as with other tumours recently reported, increased levels of epidermal growth factor receptor may be related to transformation.

Antibodies, Monoclonal↗

Attention to television: intrastimulus effects of movement and scene changes on alpha variation over time.

Central and occipital EEG alpha were used as an on-line measure of momentary changes in covert attention during television viewing. Alpha was recorded during nine 30-second commercials shown embedded in a half-hour situation comedy. Two time series were constructed for data analysis. A stimulus series consisted of codes representing the presence or absence of scene changes or person and object movement for each half-second interval of the commercials. The alpha series consisted of median alpha scores for each half-second interval, aggregated across 26 subjects. The alpha series was regressed on the movement and scene change series, both of which produced significant increments in R, even after autocorrelational effects inherent in the alpha series were removed. As a validity check on the attentional interpretation of alpha, it was shown that mean alpha for each commercial was significantly (negatively) correlated with recall and recognition of commercial contents. The results are discussed in terms of their implications for further use of continuously-recorded alpha in research on factors that influence attention to television.

Adult↗

Cerebral evoked potentials: a historical review of the marseilles contributions and a preliminary report on a study of the effects of various stimulus parameters on the P90 component of the pattern visual evoked potential.

A preliminary report is given of a study in 10 normal subjects comparing the laterality of the P90 component of the PVEP as elicited by pattern reversal and pattern appearance stimuli delivered monocularly and binocularly in the central and peripheral portions of one-life field. P90 was shown often to appear maximally over the hemisphere ipsilateral to the stimulus field with pattern reversal stimuli in central targets viewed monocularly. Pattern appearance, peripheral targets and binocular stimulation provoked less consistently lateralized and sometimes differently configured responses. It is concluded that while all combinations provoked responses consistent with a dipole generator model similar to that proposed by Blumhardt et al. (1978), these different modes of stimulation cannot be considered to be equivalent.

Cerebral Cortex↗

A comparison of visual, brainstem auditory, and somatosensory evoked potentials in multiple sclerosis.

Multimodality evoked potentials testing including PVEPs, SEPs and BAEPs was done in 112 patients who were known or suspected to have multiple sclerosis. The incidence of abnormal evoked potential findings in each of these systems was considered in patients in the different diagnostic categories of M.S. Results were also evaluated with respect to the presence of abnormal clinical visual, somatosensory, or brainstem signs. The PVEP was found to be the most frequently abnormal in even patients without clinical involvement in the visual system (45% of patients with definite, probable, or possible M.S.), the SEP was less frequently abnormal in the absence of clinical signs (35% in patients with M.S.), and the BAEP showed the lowest frequency of abnormalities in patients without brainstem signs (14% in patients with M.S.). Combining the three types of evoked potentials significantly increased the percentage of M.S. patients having abnormal findings, compared to any of these tests alone, with 97% of "definite" M.S. patients, 86% of "probable" M.S. patients and 63% of "possible" M.S. patients having at least one of these EP tests abnormal.

Adult↗

The natural history of the frozen shoulder syndrome.

A prospective study has been made of 49 patients with the frozen shoulder syndrome (as distinct from tendinitis, calcific deposits and frozen shoulders occurring after coronary infarction or with pulmonary tuberculosis) of whom forty-one have been followed up for 5-10 years, always to their greatest recovery. There were three consecutive stages: pain, stiffness, and recovery. The stiffness stage was usually related to the duration of the recovery stage. The total duration was longer than is generally supposed (an average total of 30.1 months in contrast to about 18 months as often postulated). Generally speaking, the longer the stiffness stage is, the longer is the recovery stage. In 4 patients the second shoulder became similarly affected, 6 months to 7 years after the first, and followed a similar chronological sequence to the first. After greatest recovery, slight restriction of movement was found in more than half the cases, but in only 3, all of long duration, was the restriction a handicap. Arthrography, carried out on both shoulders in all patients during the recovery stage, showed in the affected shoulder fewer rotator cuff defects than expected at this age and fewer (four) than in the contralateral one (twenty-three); seemingly, the condition leads to the obliteration of some defects.

Adult↗

Evaluation of silicone as an artificial lubricant in osteoarthrotic joints.

Silicone 300 has been evaluated as an artificial lubricant in osteoarthrotic joints by means of a pilot study in five inpatients and a control trial of 25 outpatients with 40 osteoarthrotic knees. Sequential analysis showed a significant benefit from saline compared with silicone at one week follow-up and no significant difference at one month.Measurement of stiffness with a knee arthrograph showed no difference in reduction of stiffness between the two substances. In a study of 18 rabbits there was no evidence that silicone was retained in the joint cavity for longer than 48 hours. There was a failure of clearance of iodinated serum albumin for as long as three to four days after the injection of silicone, suggesting some obstruction to lymphatic outflow. Experimentally produced cartilaginous defects did not heal quicker with the injection of silicone into the joint.

Animals↗

Danger of airguns.

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Accident Prevention↗