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Biomedical subjects

D Miller

Publications and source records attributed to D Miller.

At least 271 records · Page 15Linked to original sources

Expression of the rubella virus structural proteins by an infectious Sindbis virus vector.

To assess the potential of an infectious Sindbis virus vector (dsSIN) as a eukaryotic expression vector, dsSIN recombinants which contain each of the rubella virus (RUB) structural proteins (C, E2, and E1) individually were constructed. Expression of the RUB proteins by each dsSIN recombinant was robust and processing was similar to that observed when these proteins were expressed using other vectors. The C and E2 recombinants, each of which contains a cassette of less than 1,000 nts, were stable through low multiplicity amplification; however, the E1 recombinant, which contains a 1700 nt cassette, was not. Therefore, use of the E1 recombinant is restricted to stock derived from the original transfection. The replication rate of dsSIN and the C and E2 recombinants was similar, however, the replication rate of the E1 recombinant was slower. No phenotypic mixing of any of the RUB proteins in recombinant dsSIN virions could be detected.

Animals↗

Beta 1 integrins in third trimester human placentae: no differential expression in pathological pregnancy.

Integrins are a group of cell surface receptors that play important roles in cell-cell and cell-extracellular matrix interactions. The expression of trophoblast cell surface integrin subunits changes during placental development in normal pregnancy but the functional significance is unknown. The aim of this study was to investigate the expression of beta 1 integrins and their extracellular matrix ligands in human placenta and membranes in normal and pathological pregnancy using an avidin-biotin-peroxidase technique. Expression of the beta 1 integrins was similar in all study groups. Whilst there was some heterogeneity of expression of specific integrin alpha chains this was not characteristic of defined subject groups, variations occurring within all groups. Two distinct trophoblast subpopulations were demonstrated in the chorion laeve according to differential expression of beta 1 integrins. Trophoblast immediately adjacent to maternal decidua, which expressed alpha 1 rather than alpha 2, also comprised the majority of trophoblast in the basal plate; possession of the alpha 1, alpha 3, alpha 5, alpha 6 rather than alpha 2, alpha 3, alpha 5, alpha 6 phenotype may be important in the invasive potential of trophoblast populations. The results obtained in the present study indicate that the integrin phenotypes of third trimester uteroplacental tissues are similar in normal and pathological pregnancy, including pre-eclampsia, before and after labour.

Extracellular Matrix↗

Maternal levels of serum-soluble CD8 and IL-2R are not significantly elevated in idiopathic preterm labour.

OBJECTIVE: To search for evidence of immune activation in idiopathic preterm term labour by measuring the soluble markers of T cell activation, CD8 (sCD8) and interleukin-2 receptor (sIL2R). DESIGN: Serum sCD8 and sIL-2R were measured by commercial ELISA in subjects undergoing idiopathic preterm labour (PTL; n = 15) and normal term labour (TL; n = 17). Two gestationally equivalent non-labouring groups were also included representing preterm (PTC; n = 10) and term (TC; n = 10) controls. Possible delayed responses in soluble activation markers were monitored in blood samples taken 48 h after delivery in both labouring groups (PTLp; n = 9: TLp; n = 9). RESULTS: (1) Excluding the 48 h postpartum samples, no statistically significant differences were revealed following a Kruskall-Wallis analysis of variance (ANOVA) for levels of sIL-2R (P = 0.093) and sCD8 (P = 0.098). Including the postpartum samples, however, gave statistically significant differences for each (sIL-2R: P = 0.033; sCD8: P = 0.006). (2) No statistically significant difference was revealed by direct comparison of the two labouring groups alone (Wilcoxon-Mann-Whitney test: P > 0.05). (3) Significantly lower levels of sCD8 were found in the PTL subgroup which had histological evidence of inflammation (Wilcoxon-Mann-Whitney: P = 0.003). CONCLUSIONS: Statistical analysis of our data suggests that idiopathic preterm labour is not commonly associated with significant elevations in circulating sCD8 or sIL-2R levels compared with normal term labour. Where significant changes in the levels of these markers do arise, our evidence points to a delayed effect of labour per se rather than infection as the most probable cause.

Analysis of Variance↗

Minimum bactericidal concentrations of Propionibacterium acnes isolates from cases of chronic endophthalmitis.

Six isolates of Propionibacterium acnes recovered from cases of chronic infectious endophthalmitis following extracapsular cataract extraction were tested for antibiotic susceptibility. All isolates were susceptible to penicillin, cefazolin, and vancomycin with a macrobroth dilution method. Minimum bactericidal concentrations testing at 72 h revealed that six of six isolates were killed by < or = 1.0 micrograms of vancomycin/ml, one of six isolates by < or = 1.0 micrograms of penicillin/ml, and zero of six isolates by < or = 1.0 micrograms cefazolin/ml.

Anti-Bacterial Agents↗

Infection after radial keratotomy.

PURPOSE/METHODS: Eight years after eight-incision radial keratotomy, a corneal ulcer developed around the inferotemporal incision in an otherwise healthy 39-year-old man. There was no history of corneal trauma or contact lens wear. RESULTS/CONCLUSIONS: Both Fusarium and Acanthamoeba organisms were eventually isolated from the ulcer. A therapeutic keratoplasty was performed. Inferotemporal incisions may be predisposed to epithelial breakdown and infection many years after radial keratotomy.

Acanthamoeba↗

Non-syncytial sources of fetal DNA in transcervically recovered cell populations.

We have previously shown that fetal DNA can be detected in swabs and flushings obtained from the lower uterine pole prior to the termination of pregnancy. The presence of syncytiotrophoblast vesicles in transcervically retrieved samples suggested that this distinctive placental tissue was an abundant source of fetal DNA and a valuable resource in prenatal diagnosis strategies. In a more extensive study involving 150 terminations of pregnancy between 7 and 17 weeks gestational age, 29% of transcervically retrieved samples contained visible syncytial vesicles. Flushing of the uterine pole more frequently contained syncytia than direct aspiration (39% compared with 26% of samples) but this difference was not statistically significant. No samples > 14 weeks gestational age contained syncytia. Polymerase chain reaction analysis using Y-sequence specific-nested primers indicated the presence of fetal DNA in the absence of intact syncytial vesicles. We therefore examined samples by in-situ hybridization using Y-specific DNA probes. Positive labelling was observed in syncytial vesicles where present and in clumps of unidentified fetal cells. In addition, high numbers of naked nuclei were labelled in samples devoid of syncytia. These isolated nuclei are possibly derived from disrupted syncytia, and may be an important and hitherto overlooked contributory factor in fetal material which collects at the lower uterine pole.

Cervix Uteri↗

Temporal patterns of uncoupling between oxidative metabolism and regional cerebral blood flow demonstrated by functional magnetic resonance imaging.

RATIONALE AND OBJECTIVES: Brain activation can be detected by functional magnetic resonance imaging. Termination of stimulation can cause drop of postactivation signal below preactivation baseline; the nature of this "undershoot" remains controversial. The authors investigated postactivation signal after stimulation of the visual cortex with photic stimuli of different duration. METHODS: Activation of visual cortex in 11 healthy subjects was studied. The authors underwent short and long stimulation. The relation between activation and postactivation signal was investigated after both durations of stimulation. RESULTS: Average postactivation signal after short stimulation was -1.71 +/- 2.66% and after long stimulation 0.82 +/- 1.59% (P < or = 0.01). Significant "undershoot" was detected after short stimulation in the majority of cases, although this was typically absent after long stimulation. CONCLUSIONS: The authors propose that "undershoot" is caused by decreased oxygen content in venous blood compared with the preactivation level and may reflect increased extraction of oxygen as a result of glycolytic metabolism. The absence of "undershoot" after longer stimulation suggests a gradual shift from uncoupling between regional cerebral blood flow and oxygen consumption toward a steady state.

Adult↗

Self-report measures for assessing treatment outcomes in cardiac surgery patients.

Patient self-report measures are increasingly valued as outcome variables in health services research studies. In this article, the authors describe the Functional Status, Health Related Quality of Life, Life Satisfaction, and Patient Satisfaction scales included in the Processes, Structures, and Outcomes of Cardiac Surgery (PSOCS) cooperative study underway within the Department of Veterans Affairs health care system. In addition to reporting on the baseline psychometric characteristics of these instruments, the authors compared preoperative Medical Outcomes Study SF-36 data from the study patients with survey data from a probability sample of the US population and with preoperative data on cardiac surgery patients from a high volume private sector surgical practice. Descriptive analyses indicate that the SF-36 profiles for all of the cardiac patients are highly similar. The Veterans Affairs and private sector patients report diminished physical functioning, physical role functioning, and emotional role functioning as well as reduced energy relative to an age-matched comparison sample. At the same time, however, the Veterans Affairs patients evidenced lower levels of capacity on most of the SF-36 dimensions relative to the private sector patients.

Cardiac Surgical Procedures↗

Application of solid state detectors for dosimetry of therapeutic proton beams.

A PTW Riga diamond detector and LiF TLDs have been evaluated for use in proton beam dosimetry by comparing results of proton beam calibration with those obtained using thimble ionization chambers. The thimble ionization chambers were calibrated in terms of exposure while the TLDs and diamond detector were calibrated in terms of absorbed dose in a 60Co beam. Absorbed doses to muscle in proton beams for ionization chambers were derived using the TG 20 charged particle protocol. Absorbed doses to muscle for solid state detectors were derived using absorbed dose proton beam quality correction factors. Differences between the derived doses for ionization chambers and solid state detectors were found to be within the uncertainties of measurements: 4.5% for ionization chambers and 5% for solid state detectors.

Cobalt Radioisotopes↗

Oligoclonal banding of IgG in CSF, blood-brain barrier function, and MRI findings in patients with sarcoidosis, systemic lupus erythematosus, and Behçet's disease involving the nervous system.

A retrospective study of CSF and serum analysis from a total of 43 patients with sarcoidosis, 20 with systemic lupus erythematosus, and 12 with Behçet's disease with neurological involvement found local synthesis of oligoclonal IgG using isoelectric focusing and immunoblotting in 51%, 25%, and 8% respectively at some stage in their disease. Blood-brain barrier breakdown, when assessed with an albumin ratio found 47% of patients with sarcoidosis, 30% of those with systemic lupus erythematosus, and 42% of patients with Behçet's disease exhibiting abnormal barrier function at some time. Serial CSF analysis showed that clinical relapses were associated with worsening barrier function and in some patients the development of local oligoclonal IgG synthesis; conversely steroid treatment led to a statistically significant improvement in barrier function, and in two patients a loss of oligoclonal IgG bands. A higher proportion of patients had MRI abnormalities than oligoclonal IgG or blood-brain barrier breakdown, MRI being abnormal in 16 of 19 patients with sarcoidosis, three of four patients with systemic lupus erythematosus, and seven of nine patients with Behçet's disease, although this may have been due to temporal factors. In the differential diagnosis of chronic neurological disorders, locally synthesised oligoclonal IgG cannot distinguish between diseases, but the loss of bands seen in two patients contrasts with what is seen in multiple sclerosis, and thus may be a useful diagnostic clue.

Behcet Syndrome↗

Correlational studies of the Scale for the Assessment of Negative Symptoms and the Scale for the Assessment of Positive Symptoms: an overview and update.

The interrelationships between the various symptoms of schizophrenia may be explored by examining their intercorrelations. Five different factor analytic studies, which examine these interrelationships, are summarized. Three major factors emerge consistently: psychotic, disorganized, and negative. These three factors appear to represent three dimensions of the psychopathology of schizophrenia.

Factor Analysis, Statistical↗

Placental heat shock proteins: no immunohistochemical evidence for a differential stress response in preterm labour.

The aetiology of idiopathic preterm labour remains obscure. The hypothesis that a stress response induced by low-grade bacterial infection in utero-placental tissues was investigated. Distribution of cognate and inducible isoforms of heat shock proteins (HSP) 70 kD, HSP 60 kD and HSP 90 kD were investigated in an immunohistochemical study of placental and decidual tissues before and after labour at varying gestations. Subjects were pregnant women undergoing singleton delivery after idiopathic preterm labour at less than 34 weeks' gestation (n = 23); spontaneous term labour at 37-42 weeks' gestation (n =24); preterm caesarean sections at less than 34 weeks' gestation for preeclampsia or intrauterine growth retardation (n=14); elective caesarean section at 37-42 weeks' gestation for cephalopelvic disproportion (n = 6). HSP expression was constant throughout the third trimester of pregnancy and did not change following the onset of labour, regardless of gestational age. A stress response in decidual tissues as determined by immunohistochemical analysis is apparently not associated with preterm labour.

Bacterial Infections↗

Cyclo-oxygenase distribution in human placenta and decidua does not change with labour after term or preterm delivery.

Our objective was to determine, in an immunohistochemical study, the distribution of cyclo-oxygenase in placental and decidual tissues before and after labour at varying gestations. Subjects were pregnant women undergoing singleton delivery after idiopathic preterm labour at less than 34 weeks' gestation (n = 13); spontaneous term labour at 37-42 weeks' gestation (n = 11); preterm caesarean section at less than 34 weeks' gestation for pre-eclampsia or intrauterine growth retardation (n = 8); elective term caesarean section at 37-42 weeks' gestation for cephalopelvic disproportion (n = 7). Within the placental basal plate cyclo-oxygenase was localised in decidual stromal cells, extravillous trophoblast, and the apical border of villous syncytiotrophoblast, both before and after labour, regardless of gestational age. Within the placental membranes, decidual stromal cells showed intense cytoplasmic cyclo-oxygenase labelling and the chorion laeve strong membrane-associated cyclo-oxygenase reactivity before and after labour, regardless of gestational age. The amnion showed a heterogeneous staining pattern. After labour at term there was either positive cytoplasmic (5/10) or apical staining (5/10). Cyclo-oxygenase was demonstrated in an apical distribution in only 50% of the other subject groups. Cyclo-oxygenase is present in both decidua and placental tissues prior to the onset of labour at term. Demonstration of decidual and trophoblastic cyclo-oxygenase in both preterm and term subjects suggests that differential availability of cyclo-oxygenase is unlikely to be important in preterm delivery. Research into the withdrawal of inhibition or increased substrate availability is most likely to shed light on the signal pathways involved in the onset of labour, regardless of gestation.

Cell Membrane↗

Human gene transfer.

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Gene Transfer Techniques↗

Assessing patient willingness to reveal health history information.

A survey was designed to determine how willingly patients reveal personal health information on dental health history forms. After giving informed consent, 107 patients at a university dental hygiene program completed a 10-item survey privately and anonymously. The results suggest that a significant number of patients provide inaccurate or incomplete information to questions routinely asked on the dental health history form.

Adult↗

Evidence for oestrogenic regulation of heat shock protein expression in human endometrium and steroid-responsive cell lines.

Gene amplification with target-specific primers (reverse-transcription polymerase chain reaction (RT-PCR)) was used to monitor the relative expression of oestrogen and progesterone receptor mRNAs alongside the mRNAs for heat shock proteins HSP 90 alpha, HSP 90 beta and HSP 70a in normal samples of human endometrial tissue over the whole menstrual cycle and in short-term cultures of steroid-responsive (T47-D) and unresponsive (HRT-18) cell lines exposed to oestradiol and progesterone over a 24-h incubation period. In endometrium, oestrogen and progesterone receptors followed the expected patterns of expression at the protein level during the menstrual cycle and also showed a positive correlation of expression with each other throughout (r = 0.514). Of the HSPs only HSP 90 alpha expression correlated positively with oestrogen receptor (r = 0.687), while HSP 70a expression, which peaked in the late secretory stage, displayed a significantly inverse correlation with HSP 90 beta expression (r = -0.526). All p values < 0.05. In T47-D cell cultures, oestrogen receptor expression was stimulated transiently by oestradiol (10(-7) mol/l) and more persistently by progesterone (10(-7) mol/l). Progesterone receptor expression was depressed by progesterone and weakly stimulated by oestradiol. HSP 70a and HSP 90 alpha expression were stimulated by oestradiol. Progesterone generally depressed HSP 90 alpha expression and simultaneous addition of both oestradiol and progesterone to the culture medium was antagonistic to HSP 90 alpha expression. No clear effect of agonist addition on HSP mRNA expression was apparent in the HRT-18 cultures. A possible mechanism for observed oestrogenic effects on HSP expression is put forward.

Actins↗

Laryngograph: speech pattern element tools for therapy, training and assessment.

The clinically based, real-time analysis of speech into physically definable elements, which are of direct perceptual and productive importance, has become more readily possible in recent years as the result of microprocessor developments. The combination of the acoustic signal of speech derived from a microphone together with the accompanying Laryngograph signal provides the basis for a highly reliable set of facilities. The paper describes methods and results for the analysis of voice, frication and timbre for both quantitative analysis and teaching and therapy using interactive visual displays. A brief discussion is given of links to work in stroboscopy, electropalatography and the associated use of additional sensors. Finally reference is made to a complete clinical work station combining these different facilities together with the quantitative analytical procedures of the speech pattern audiometer.

Humans↗