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Biomedical subjects

S Ellis

Publications and source records attributed to S Ellis.

At least 91 records · Page 5Linked to original sources
PubMed1996

Colonic expression of c-myb is initiated in utero and continues throughout adult life.

c-myb expression is an indicator of hemopoietic cell proliferation and its down-regulation occurs as an early event in cellular differentiation in vitro. We have previously demonstrated c-Myb protein expression in normal adult colon and tumor-derived colonic cell lines and have also shown that the proliferation of colon carcinoma cell lines is c-myb dependent. This study used the techniques of RNase protection and immunohistochemistry to define c-myb mRNA and protein expression in the normal adult mouse and mouse embryos, with special focus on the colon. These experiments revealed wide-spread c-myb mRNA expression in mouse embryos including nonhemopoietic tissues, and developmental time course studies revealed alterations in organ-specific c-myb mRNA expression. Immunohistochemical studies confirmed the embryonal expression of c-Myb in concordance with the mRNA data as well as c-Myb expression throughout the length of the adult mouse colonic crypt. In contrast, staining for the proliferating cell nuclear antigen was confined to the lower one third of the crypt. In addition, c-Myb staining extended beyond that of the proliferating cell nuclear antigen within the germinal centers of the spleen. These data suggest that c-myb: (a) has a role in the embryonic development of nonhemopoietic organs; (b) plays a specific role in the biology of the normal adult colonic crypt; and (c) expression is not inextricably linked to proliferation in vivo.

Animals↗
PubMed1995

Microwaves for menorrhagia: a new fast technique for endometrial ablation.

Current ablative techniques for treating menorrhagia are unsatisfactory. We tried microwave energy, delivered by an 8 mm diameter probe in the uterine cavity, to treat 23 patients with functional menorrhagia. The mean treatment time was 2 min 12 s (range 50-310 s). 6 months after treatment the success rate is 83%, 13 patients (57%) are amenorrhoeic, and six (26%) are experiencing light menstruation. Three initial failures have been successfully retreated. The technique is safe, and is easier and quicker to perform than current alternatives.

Adult↗
PubMed1995

Plasminogen activators augment endothelial cell organization in vitro by two distinct pathways.

Endothelial cell differentiation into capillary structures is a complex process that requires the concerted effects of several extracellular matrix proteases, including plasminogen activators. Here, the role of tissue-type plasminogen activator (tPA) and urokinase-type plasminogen activator (uPA) was evaluated in an in vitro model of endothelial morphogenesis involving organization of human umbilical vein endothelial cells into tubular structures when they are cultured on the basement membrane preparation, Matrigel. Both uPA and tPA were detected in HUVEC cultures on Matrigel, and inhibitors of plasminogen activators or of serine proteases decreased the extent of the tube network formed by the cells. The decrease resulting from serine protease inhibitors was additive to that from matrix metalloproteinase inhibitors which have previously been shown to decrease tube formation in this model, suggesting that the two classes of proteases modulate tube formation by distinct mechanisms. Plasminogen activator inhibitor (PAI)-1 decreased tube formation by 50% when added up to 4.5 h after the initiation of an 18 h assay and caused 25% inhibition when added 9.5 h after culture initiation, indicating that the effects of plasminogen activators are not limited to an early event in the differentiation process. Steady-state expression of mRNA for uPA increased during the first several hours of culture on Matrigel, further supporting a role for PA activity throughout the process of tube formation. These findings suggested that PAs may affect multiple events during tube-forming activity. A fucosylated peptide comprising the amino-terminal domain of uPA that binds to the uPA receptor (uPAR) but lacking proteolytic activity enhanced tube formation. In contrast, a defucosylated form of the same peptide had no effect. Since fucosylation of this fragment has been shown to be essential in other models of cell stimulation by uPA-uPAR interaction, these data support the hypothesis that uPA enhances endothelial morphogenesis both through proteolytic activity and via uPAR occupancy. Plasminogen activators could facilitate angiogenesis in vivo.

Capillaries↗
PubMed1995

Physician training for patient-centered nutrition counseling in a lipid intervention trial.

BACKGROUND: We examined the effect of a 3-hr training program on physicians' lipid intervention knowledge, attitudes, and skills. The program teaches physicians skills to conduct a brief dietary risk assessment and provide patient-centered counseling to enable patients with elevated lipids to change their dietary patterns. METHOD: The training is part of a randomized trial of lipid-lowering interventions, the Worcester Area Trial for Counseling in Hyperlipidemia. Primary care internists practicing in a health maintenance organization (HMO) were assessed, before and after training using questionnaires and audiotapes to document changes in knowledge about diet, attitudes about intervention, reported nutrition intervention practices, and counseling and assessment skills. Physicians also rated the value that they thought the training program had to them. RESULTS: After completion of the program the physicians' use of dietary counseling steps, as assessed by blinded evaluation of audiotaped physician-patient interactions, significantly increased (mean pre = 5.4, mean post = 9.2; t = 9.9; P < or = 0.001). In this regard, there were instances in the use of 7 of the 14 specific counseling steps. Physicians also demonstrated increases in self-perceived preparedness as measured by a 5-point scale (mean pre = 3.2, mean post = 4.0; t = 4.25; P < 0.001), confidence in having an effect (mean pre = 3.3, mean post = 3.9; t = 3.16; P < 0.01), perception that materials were available to aid intervention (mean pre = 2.7, mean post = 4.0; t = 5.29; P < 0.001), and perception that they have access to a nutritionist (mean pre = 3.5, mean post = 4.0; t = 2.63; P < 0.01). They rated the value of the program between very good and excellent. CONCLUSION: Results of this 3-hr educational program indicate that physicians in an HMO are responsive to the teaching of specialized skills deemed important for promoting health behavior change in their patients.

Adult↗
PubMed1995

Immunization with class I human histocompatibility leukocyte antigen can protect macaques against challenge infection with SIVmac-32H.

OBJECTIVE: To evaluate the efficacy of immunopurified class I human histocompatibility leukocyte antigen (HLA) to protect against SIV infection. METHODS: HLA class I antigens were immunopurified from a human B-lymphoblastoid cell line. Groups of four macaques were vaccinated subcutaneously with four doses of the immunogen in adjuvant, or with adjuvant alone and subsequently challenged intravenously with 10 median monkey infectious doses of cell-free SIVmac-32H. Infection was determined by polymerase chain reaction for SIVmac proviral DNA and by virus isolation. Antigen-specific humoral and cellular immune responses were monitored. RESULTS: Macaques immunized with the HLA molecules produced anti-HLA class I antibodies that inhibited SIV replication in vitro and downregulated autologous T-cell proliferation against irradiated C8166 cells. They were partially protected (two out of four) from virus infection for at least 33 weeks when challenged with SIV grown in human cells. All four control animals were infected. CONCLUSIONS: This demonstration of partial protection, together with our previous work reporting that vaccination with allogenic cynomolgus lymphocytes can protect against challenge infection with SIV grown in simian cells, suggests that allogenic immune response induced before or during establishment of HIV infection may have important implications for AIDS disease progression.

Animals↗
PubMed1994

How lateralised is visuospatial neglect?

Seventeen patients with left visuospatial neglect caused by cerebral infarction undertook the six subtests of the Behavioural Inattention Test (BIT) as soon as possible following their neurological event. The group mean results on line, letter and star cancellation tasks revealed a linear decrement in performance from right to left on the displays. However, subsequent analysis of patients' cancellations revealed that this finding was not representative of individual performance. Many patients in fact made both marked left- and right-sided omissions on the three cancellation tasks. This was not merely a transitory phenomenon because it remained present at weekly follow-up intervals. Patients' performance on a laterally extended version of the star cancellation task was also investigated. These findings strongly suggest that patients with visuospatial neglect can initially present with a diverse range of performance deficit. Many patients, in particular those with the lowest BIT scores, showed a consistent pattern in the results on letter and star cancellation, providing evidence that their inattention consistently included a considerable section of right-sided (including the extreme right of displays) as well as left-sided space.

Aged↗
PubMed1994

Left visuo-spatial neglect can be worse in far than in near space.

We tested five patients with marked left-sided visuo-spatial neglect and two control subjects on a test of line bisection. A series of horizontal lines was presented to each subject, who had to indicate the centre with a projection light-pen. All five patients misplaced the centre to the right, in accordance with their left-sided neglect. However, in all five the angular displacement was greater for lines well beyond reach, than for lines of identical angular size within reaching distance. This result, precisely because it is opposite to that of a previous report, supports the conclusion that there are separate dissociated neural systems concerned with the perception of, and response to, stimuli in near and far space.

Aged↗
PubMed1994

Polymorphism of bovine MHC class I genes. Joint report of the Fifth International Bovine Lymphocyte Antigen (BoLA) Workshop, Interlaken, Switzerland, 1 August 1992.

The objectives of the Fifth International BoLA Workshop were to: standardize nomenclature, compare typing methods, and characterize BoLA haplotypes. The workshop was based on the distribution of blood samples (cells) from 60 selected cattle to 14 laboratories. Results for the class I (BoLA-A) region are presented in this paper while results for the class II regions are presented in a separate report. Thirty-six of the 50 previously established serological class I specificities were represented in the cell panel. However, only 30 specificities could be confirmed. Two specificities, A16 and A32, were upgraded from provisional, workshop (w) specificities to BoLA-A locus specificities and three new specificities, w51(w28), w52 and w53(w28), were defined. The 39 specificities distinguished 30 class I haplotypes in the 60 animals. Class I isoelectric focusing proved to be a useful adjunct to the serology. Isoelectric focusing confirmed several serologically defined splits and detected splits of A15(A8), A18(A6) and A22(w49) that had not been detected by serology. Subsequently, serological support for splits of A15(A8) and A22(w49) was found.

Animals↗
PubMed1994

Brief remission periods in visuospatial neglect: evidence from long-term follow-up.

Ten patients with left-sided visuospatial neglect due to cerebrovascular accident were monitored using the Behavioural Inattention Test (BIT) at weekly intervals, on a long-term basis. The novel finding was that some patients showed occasional but transitory marked improvement in their visuospatial neglect at times producing a normal score. This spontaneous phenomenon was evidenced by the patient cancelling sections or the entire block of left-sided targets, without any additional cues or prompts. Such episodes indicate that, in this small group of patients, visuospatial neglect is not necessarily irrevocable, at least for simple stimuli.

Aged↗
PubMed1993

Fate of lesion-related side branches after coronary artery stenting.

OBJECTIVES: The aim of this study was to assess the immediate and long-term patency of lesion-associated side branches after coronary artery stenting. BACKGROUND: The possible adverse effects related to implantation of coronary stents are not completely known. An important potential complication of stenting is side branch occlusion due to mechanical obstruction or thrombosis. METHODS: Serial coronary angiography was performed in 153 patients (167 lesions) at baseline, after conventional balloon angioplasty, immediately after Palmaz-Schatz stent placement and at 6 months. The patency of side branches, where present, was analyzed at each of these points. RESULTS: Of 167 lesions stented, 57 stent placements spanned 66 side branches with a diameter > or = 1 mm. Twenty-seven (41%) of these side branches had > or = 50% ostial stenosis before standard balloon angioplasty. Six side branches became occluded after standard balloon angioplasty and remained occluded after stenting. Of the 60 side branches patent after conventional angioplasty, 57 (95%) remained patent immediately after stenting. All three side branches that became occluded after stenting had > or = 50% ostial stenosis at baseline. All 60 side branches, including the 3 initially occluded after stenting, were patent at 6-month follow-up. CONCLUSIONS: These findings demonstrate that 1) acute side branch occlusion due to coronary stenting occurs infrequently; 2) when side branch occlusion occurs, it is associated with intrinsic ostial disease; and 3) the patency of side branch ostia is well maintained at long-term follow-up.

Adult↗
PubMed1993

The recording and analysis of EMG and jaw tracking. II. Reproducibility of jaw tracking.

In 10 male and 10 female adults jaw movements and muscle activity were monitored during chewing. Subjects had a Class I occlusion and fluent unrestricted jaw movements; non exhibited signs or symptoms of craniomandibular disorders. Recordings were made on two occasions separated by 2 weeks. Within each recording session the subjects carried out a number of tasks under direction, including eating nuts and gum. The jaw movements were monitored with a Sirognathograph which had been interfaced to a computer for data logging and analysis. A computer program identified each chewing stroke and after scrutiny a data base was constructed of measurements from a subset of 4447 suitable strokes. Mean values of 10 parameters selected to describe jaw movements during chewing were entered into an ANOVA. This indicated that the major contribution to variance was due to the subject from whom the data was recorded. This intersubject variability is well known, but can its separation from the other contributions to the variation within the data be assessed? To provide an estimate of the spread of data the variance for each parameter was calculated, transformed and these values entered into an analysis of variance. All subject differed significantly in their chewing movements from one another. But 15 of the 20 subjects showed a greater degree of consistency than the other five: they exhibited good inter- and intra-recording reproducibility. The food being eaten made a major contribution to the variability. The timing of the chewing strokes was also more consistent than the dimensions of the chewing envelope.

Adult↗
PubMed1993

Typing of strains from a single-source outbreak of Pseudomonas pickettii.

Plasmid profiles, genome restriction fragment polymorphisms, carbohydrate oxidation-fermentation reactions, methylumbelliferyl substrate hydrolysis patterns, antimicrobial susceptibilities, and results obtained with the Biolog GN biochemical substrate kit were used to type 19 common-source, but mixed-biotype, outbreak strains and one epidemiologically distinct strain of Pseudomonas pickettii. Biotyping with conventional and methylumbelliferyl substrates failed to distinguish between strains. Plasmid profile testing was found to be inconsistent and not reproducible. The Biolog GN kit allowed greater strain differentiation than restriction fragment polymorphism did (12 biotypes versus 5 biotypes); antimicrobial susceptibility testing yielded 4 biotypes, and oxidation-fermentation tests gave 3 biotypes. Oxidation-fermentation results were consistent with restriction fragment polymorphs in all but 1 of the 20 strains tested. For ease of typing, comprehensive typeability, and reproducibility, oxidation-fermentation tests should be performed initially and followed if necessary by restriction fragment polymorph analysis for the elucidation of P. pickettii infection outbreaks.

Bacterial Typing Techniques↗
PubMed1993

HIV awareness at work.

Shared personal and professional awareness of and commitment to HIV issues in employment prompted Sue Ellis and Liz Smart to set up a project which, through collaborative working between health promotion, personnel functions and trade unionists, would devise training materials to address employment issues and reduce concern about HIV infection in the workplace.

Acquired Immunodeficiency Syndrome↗