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Biomedical subjects

E Stewart

Publications and source records attributed to E Stewart.

At least 55 records · Page 3Linked to original sources
PubMed1993

ABL-BCR mRNAs transcribed from chromosome 9q+ in Philadelphia-chromosome-positive chronic myeloid leukaemia.

Polymerase chain reaction amplification of reverse transcription products has demonstrated the presence of abl-bcr hybrid mRNAs in RNA from peripheral blood leucocytes of Philadelphia-chromosome-positive chronic myeloid leukaemia patients; such hybrid mRNAs can contain either of the alternative first exons of c-abl. A survey of 12 CMLs has shown that abl-bcr mRNAs occur in the leucocytes of some, but not all, patients, and that they are present both in chronic-phase and acute-phase leucocytes.

Base Sequence↗
PubMed1992

Identification of the domains in cyclin A required for binding to, and activation of, p34cdc2 and p32cdk2 protein kinase subunits.

The binding of cyclin A to p34cdc2 and p32cdk2 and the protein kinase activity of the complexes has been measured by cell-free translation of the corresponding mRNA in extracts of frog eggs, followed by immunoprecipitation. A variety of mutant cyclin A molecules have been constructed and tested in this assay. Small deletions and point mutations of highly conserved residues in the 100-residue "cyclin box" abolish binding and activation of both p34cdc2 and p32cdk2. By contrast, large deletions at the N-terminus have no effect on kinase binding and activation, until they remove residues beyond 161, where the first conserved amino acids are found in all known examples of cyclin A. At the C-terminus, removal of 14 or more amino acids abolishes activity. We also demonstrate that deletion of, or point mutations, in the cyclin A homologue of the 10-residue "destruction box," previously described in cyclin B (Glotzer et al., 1991) abolish cyclin proteolysis at the transition from M-phase to interphase.

Amino Acid Sequence↗
PubMed1991

The natural history of colorectal cancer. Opportunities for intervention.

There is now a better understanding of the natural history of colorectal cancer, which has provided a basis for intervention to influence outcome. The possible interventions include earlier detection of colorectal cancer, removal of premalignant adenomas, demonstration of the mucosal field defect that precedes neoplasia to evaluate baseline risk and its change with dietary modification, and identification of inherited and dietary risk factors. Five controlled trials evaluating early detection of colorectal cancer with fecal occult blood testing have enrolled more than 309,000 patients. Early stage cancers with improved survival has been observed, but data on mortality reduction have not as yet been reported. Studies of patients with adenomas have demonstrated high synchronous and metachronous rates as a basis for complete colon evaluation initially and a surveillance follow-up program. Hyperproliferation and lack of normal differentiation have been observed as a field defect in the colon preceding neoplasia. Inherited factors have recently been shown to be important in a larger proportion of individuals destined to develop colorectal adenomas and cancer. These observations of the natural history of colorectal cancer have provided new opportunities for the application of radiologic and endoscopic techniques in diagnosis and surveillance; each examination has its merit. Further research is needed to answer many critical questions that have been raised regarding the impact of these interventions.

Adenoma↗
PubMed1990

Maternal mRNA from clam oocytes can be specifically unmasked in vitro by antisense RNA complementary to the 3'-untranslated region.

Clam oocytes display a striking difference in the pattern of protein synthesis on fertilization, which is maintained when cell-free extracts are assayed in the rabbit reticulocyte lysate. The mRNAs encoding ribonucleotide reductase and cyclin A (the major masked messages in the oocyte extracts) can be translationally activated by gel filtration in 0.5 M KCl, presumably by removal of repressor protein(s). When synthetic RNAs corresponding to different segments of ribonucleotide reductase and cyclin A mRNAs were added to oocyte extracts in 0.5 M KCl in a "competitive unmasking" assay, specific and complete unmasking of these mRNAs occurred on addition of antisense 3'-noncoding transcripts. The unmasking region in ribonucleotide reductase mRNA maps to a region of 134 nucleotides centered one-third of the way down the 3'-noncoding region.

Animals↗
PubMed1989

Changes in internal and external pH accompanying growth of Candida albicans: studies of non-dimorphic variants.

Non-dimorphic variants of Candida albicans, which were unable to form germ tubes or mature hyphae in media containing amino acids, glucose and salts or N-acetylglucosamine or serum, were prepared from two hyphal positive laboratory strains using a physical separation method. The hyphal-minus phenotype was stable and may be due to mutations or phenotypic variation. The variant strains maintained their internal pH within narrower bounds as compared to their parental wild-types. When exposed to conditions that normally supported the induction of germ tubes the cytoplasmic pH of the wild type strains increased from 6.8 to over pH 8.0 within 5 min while in the variants the rise in internal pH was only about 0.3 pH units. The wild type strains acidified the growth medium more rapidly than the variants. The results suggest that the control of internal pH is directly or indirectly associated with the regulation of dimorphism. The variants had unaltered cell volumes and specific growth rates. The hyphal-minus phenotype was however fully reversible since revertants occurred spontaneously on serum containing agar.

Candida albicans↗
PubMed1989

The impact of group therapy for adult survivors of childhood sexual abuse.

This article reports on 95 women who were referred to an outpatient psychiatry clinic for group therapy for adult survivors of childhood sexual abuse. Criteria for exclusion in group therapy are outlined and the format of the group therapy is described. Those who completed the groups are compared to dropouts. The group's effectiveness was evaluated using measures of psychiatric symptomatology (SCL 90), depression (Zung Self-Report Depression Scale), and self-esteem (Texas Social Behaviour Inventory) with a pre/post test design. Clients' evaluation questionnaires were also used. Group therapy was found to be effective in reducing symptomatology and change was in the expected direction in terms of depression and self-esteem.

Adjustment Disorders↗
PubMed1988

Cytoplasmic alkalinization during germ tube formation in Candida albicans.

Weak acids were used to measure the internal pH of yeast cells of Candida albicans that had been induced to form buds or germ tubes. Under conditions that supported germ tube formation the internal pH rose from around 6.8 to over 8.0 after 30 min in two different induction media. Internal pH measured by 31P NMR confirmed this pattern and also showed that the internal pH fell to around 7.0 prior to the outgrowth of germ tubes. Conditions which led to budding induced less cytoplasmic alkalinization. This alkalinization was brought about when cells were inoculated into media of neutral pH and at an increased temperature. Increasing the temperature of the medium augmented the alkalinization of the cytoplasm induced by raising the external pH. Strains of C. albicans defective in the ability to produce germ tubes did not show this dramatic cytoplasmic alkalinization under conditions which normally supported filamentous growth. The raising of internal pH may be due to the activation of the plasma membrane proton-pumping ATPase since diethylstilboestrol inhibited the cytoplasmic alkalinization and germ tube formation without causing irreversible loss of cell viability. The results show that the induction of the dimorphic transition in this organism is accompanied by a steep rise in internal pH. It is not known whether these changes are the cause or consequence of morphogenesis.

Candida albicans↗
PubMed1987

Multiple chromosome abnormalities in a drug resistant TdT positive B-cell leukemia.

A 17-year old caucasian male presented with B-cell acute leukemia which proved aggressive and refractory to treatment. Cytogenic investigation showed a single clone with a complex karyotype 49,XY,del(2)(p13),+4,del(4)(p11),-6,+i(6)(p),+7,+8, t(8;14), (q24;q32),del(17)(p11). This includes the Burkitt's translocation and a deletion at the site of the immunoglobulin kappa light chain gene. Clonal evolution included tetraploidy, duplication of the derived chromosomes and, terminally, trisomy 1q. Immunological investigation revealed a monoclonal population of B-cell blasts, expressing the kappa light chain, and with an extremely rare combination of SIg and TdT positivity. Immunoglobulin gene rearrangement confirmed monoclonalility. Tetraploidy of the clone and del(17)(p11) have been previously described only in a cell line or at end stage disease in B-ALL. It is suggested that the chromosomal abnormalities present at diagnosis were directly related to the refractory nature of this leukemia.

Acute Disease↗
PubMed1985

Contraction stress testing with nipple stimulation.

The contraction stress test (CST) is used widely as a measure of fetoplacental respiratory reserve. With contractions traditionally induced by intravenous oxytocin, the test has been limited in its use by time, expense and patient discomfort. In a prospective evaluation of the effectiveness of nipple stimulation for the production of uterine contractions, a successful CST was obtained in 94% of the attempts, with a mean total test time of 12 minutes.

Adolescent↗
PubMed1983

Endoscopic retrograde cholangiopancreatography. Diagnosis of cholelithiasis in patients with normal gallbladder x-ray and ultrasound studies.

The combination of a normal oral cholecystogram and ultrasound study of the gallbladder is considered adequate evidence to exclude cholelithiasis as a cause of biliarylike pain. We examined 206 patients with biliarylike pain and normal findings on cholecystogram and ultrasound study of the gallbladder by endoscopic retrograde cholangiopancreatography (ERCP). Of the 195 patients who had successful ERCP, 32 patients (group 1) had mild, transient abnormalities in liver function tests and 163 (group 2) had normal liver function test results. Small gallstones were demonstrated on ERCP examination in 25 of 32 group 1 patients and in four of 163 group 2 patients, all confirmed at surgery or endoscopic sphincterotomy. In conclusion, despite negative results on cholecystogram and ultrasound study of the gallbladder, patients with biliarylike pain and abnormal liver function test results should be evaluated further by diagnostic ERCP examination.

Amylases↗