PubMed Health⌕ Search

Biomedical subjects

N Miller

Publications and source records attributed to N Miller.

At least 37 records · Page 2Linked to original sources

A meta-analytic, quantitative assessment of osseointegration establishment and evolution of submerged and non-submerged endosseous titanium oral implants.

Two implant placement methods are used in oral implantology: submerged (S, two-stage surgical procedure) and non-submerged (NS, one-stage surgery). However, a quantitative assessment of their influence on implant osseointegration, summarising the whole present experience, is not directly possible, owing to the lack of normalisation of the published results. To overcome this difficulty, selection criteria have been applied to the latter in a process of a meta-analysis of specialised literature, in order to authorise a pooled treatment with an adequate statistical method. Survival life tables are established (up to 15 and 10 years respectively for S and NS implants placed in normal situations) for extended samples (13049 S and 5515 NS implants). Early (before loading) failure rates and 95% confidence level ranges of cumulative implant survival rates are shown. For both categories, the quality of the placement stage remains critical to ensure optimal osseointegration behaviour. Both categories match current survival requirements, but with a quite different behaviour over time. NS implants, while osseointegrating better initially, are subject to causes of osseointegration loss, which persist over a longer period of time. Implant design characteristics (including the type of surface) seem to be more relevant than the placement procedure for the implant's behaviour. This is in agreement with recent histological and preliminary clinical results, and should be confirmed by further studies.

Dental Implantation, Endosseous↗

CD9 and HLA-DR expression by crevicular epithelial cells and polymorphonuclear neutrophils in periodontal disease.

BACKGROUND, AIMS: The composition of gingival crevicular fluid (GCF) is likely to reflect inflammatory modifications that take place in the gingiva during periodontal diseases. METHOD: In this study, GCF was collected at 3 different sites from 23 periodontal patients. The sites were assessed to be healthy, presenting gingivitis or periodontitis. 10 healthy individuals without any form of periodontal disease formed the control group and were sampled at one site each. The cell content of GCF was collected using Durapore Millipore strips, and 2 types of cells were studied: epithelial cells (EC) and polymorphonuclear neutrophils (PMN). The expression of CD9 and HLA-DR within or on the surface of these cells was studied in immunofluorescence on cytospin smears. RESULTS: Both CD9 and HLA-DR expression on EC differed significantly from control subjects, and the latter decreased according to the severity of the pathology. None of the PMN found in controls expressed CD9 or HLA-DR. However, in periodontal patients, the expression of HLA-DR within PMNs was detectable and increased according to the severity of lesions. CD9 expression on PMNs also increased with inflammation. CONCLUSION: This study shows that clinically healthy sites of periodontal patients already present signs of immunological activation characterised by a down modulation of HLA-DR expression on EC and an upregulation of these 2 molecules in PMN.

Adolescent↗

Perceptual asymmetry in consensus estimates of majority and minority members.

Three experiments revealed a consistent pattern of consensus estimates. Numerical status and group growth or decline were manipulated between subjects. Growth was manipulated orthogonally to a 3rd variable: focus. Focus was manipulated by describing growth information with respect either to the in-group or the out-group (e.g., in-group growth and out-group decline). A Numerical Status X Focus interaction emerged in Study 1. Numerical minority members' consensus estimates for an opinion issue increased when growth information was out-group focused, whereas majority members' estimates did not differ as a function of the focus variable. Study 2 replicated these effects across other opinion dimensions. Study 3 confirmed the importance of the growth and focus variables in the absence of numerical status manipulations.

Adult↗

Benefits of a joint nursing and laboratory point-of-care program: nursing and laboratory working together.

Critical care nurses contend daily with high pace, crisis-care, and dealing with patients, physicians, coworkers, and patients' family members. A point-of-care testing (POCT) program can assist with the quick decision making required of today's critical care nursing staff. By meshing the backgrounds of nursing and the central laboratory into one workable philosophy, POCT can ensure optimal patient care.

Critical Care↗

Access of target groups to 1915(c) Medicaid home and community based waiver services.

OBJECTIVES: The study examined the access of specific target groups to the 1915(c) home and community based waiver program in terms of the number of participants, services, and expenditures for 1992 and 1997. METHODS: The study collected HCFA 372 waiver program statistics from each of the states and compared statistics for the two time periods. A regression examined the increase in program expenditures. RESULTS: An unequal distribution of HCBS expenditures across target groups was found where individuals with developmental disability were 39 percent of participants but used 77 percent of the total $7.9 billion waiver expenditures in 1997. The aged and disabled were 58 percent of waiver participants but received 21 percent of expenditures. The program growth was primarily due to increases in participants and reimbursement rates. CONCLUSIONS: Individuals with MR/DD used more costly services such as habilitation and residential care than other target groups. Studies are needed to examine what accounts for the unequal access and whether program expenditures are sufficient to meet the long-term care needs of various target groups.

Adult↗

Growth factors and stromal matrix proteins associated with mammographic densities.

Extensive radiologically dense breast tissue is associated with a marked increase in breast cancer risk. To explore the biological basis for this association, we have examined the association of growth factors and stromal matrix proteins in breast tissue with mammographic densities. Ninety-two formalin-fixed paraffin blocks of breast tissues surrounding benign lesions were obtained, half from breasts with little or no density and half from breasts with extensive density, matched for age at biopsy. Sections were stained for cell nuclei, total collagen, the stromal matrix regulatory protein tissue metalloproteinase-3 (TIMP-3), and the growth factors, transforming growth factor-alpha and insulin-like growth factor (IGF-I). The area of immunoreactive staining was measured using quantitative microscopy. Breast tissue from subjects with extensive densities had a greater nuclear area (P = 0.007), as well as larger stained areas of total collagen (P = 0.003), TIMP-3 (P = 0.08), and IGF-I (P = 0.02) when compared with subjects with little breast density. Differences were greater for subjects less than 50 years of age. These data indicate that increased tissue cellularity, greater amounts of collagen, and increased IGF-I and TIMP-3 expression are found in tissue from mammographically dense breasts and suggest mechanisms that may mediate the associated increased risk of breast cancer.

Age Factors↗

Spontaneous pattern formation in an effectively one-dimensional dielectric-barrier discharge system

In a dielectric-barrier discharge between diametrically opposite sides of a narrow tube, discharge filaments stabilize at regular intervals along the tube's length. Three types of periodic patterns are observed, as is a disordered state in which filaments fire at apparently random positions and times. Time-resolved current measurements indicate that for each spatial pattern, a particular number of discharge stages occur during the voltage half-cycle. A preliminary model of the pattern-formation dynamics is described, motivating further work on time-resolved imaging and investigations of surface charge distributions.

Journal Article↗

An analysis of 78 breast sarcoma patients without distant metastases at presentation.

PURPOSE: A retrospective review of a single cancer center experience was undertaken to identify clinical or treatment prognostic factors for these unusual tumors, to allow for a recommendation regarding management. METHODS AND MATERIALS: The charts of 76 women and 2 men with breast sarcoma and without distant metastases at presentation registered from 1958 to 1990 were reviewed. Pathology was centrally reviewed in 54 cases. Histology, tumor size, grade, nodal status, age, menopausal status, history of benign breast disease, extent of surgery, resection margins, and radiation dose were each examined as potential prognostic factors by univariate analysis. To allow an analysis of radiation dose, total dose was normalized to a daily fraction size of 2 Gy. RESULTS: The median age at diagnosis was 50.5 years (13-82 years). The pathologic diagnosis was found to be malignant cystosarcoma phyllodes in 32 patients, with the remainder being stromal sarcoma (14), angiosarcoma (8), fibrosarcoma (7), carcinosarcoma (5), liposarcoma (4), other (8). Eighteen patients had grade I or II tumors, 43 had grade III or IV, and 18 were not evaluable. The 5- and 10-year actuarial rates for all 78 patients were 57% and 48% for cause-specific survival (CSS), and 47% and 42% for the relapse-free rates (RFR), respectively. The local relapse-free rate (LRFR) was 75% at both 5 and 10 years. The 5-year CSS for grade I or II tumors was 84% versus 55% for grade III or IV tumors (p = 0.01). Conservative surgery versus mastectomy did not lead to statistically significant different outcomes for CSS, RFR, or LRFR. The comparison of positive versus negative margins showed a 5-year LRFR of 33% versus 80% (p = 0.009). Pairwise comparisons of the 5-year CSS of 91% for > 48 Gy versus either 50% for < or = 48 Gy or 50% for no radiation showed p-values of 0.03 and 0.06, respectively. CONCLUSION: The authors propose that if negative surgical margins can be achieved, breast sarcoma should be managed by conservative surgery with postoperative irradiation to a microscopic tumoricidal dose (50 Gy) to the whole beast, and at least 60 Gy to the tumor bed. The decision to treat should be preceded by a preoperative multidisciplinary assessment. It is also recommended that an axillary lymph node dissection is not indicated, with the possible exception of patients with carcinosarcoma.

Adolescent↗

Comparison of immersion ultrasound biometry and partial coherence interferometry for intraocular lens calculation according to Haigis.

BACKGROUND: The precision of intraocular lens (IOL) calculation is essentially determined by the accuracy of the measurement of axial length. In addition to classical ultrasound biometry, partial coherence interferometry serves as a new optical method for axial length determination. A functional prototype from Carl Zeiss Jena implementing this principle was compared with immersion ultrasound biometry in our laboratory. PATIENTS AND METHODS: In 108 patients attending the biometry laboratory for planning of cataract surgery, axial lengths were additionally measured optically. Whereas surgical decisions were based on ultrasound data, we used postoperative refraction measurements to calculate retrospectively what results would have been obtained if optical axial length data had been used for IOL calculation. For the translation of optical to geometrical lengths, five different conversion formulas were used, among them the relation which is built into the Zeiss IOL-Master. IOL calculation was carried out according to Haigis with and without optimization of constants. RESULTS: On the basis of ultrasound immersion data from our Grieshaber Biometric System (GBS), postoperative refraction after implantation of a Rayner IOL type 755 U was predicted correctly within +/- 1 D in 85.7% and within +/- 2 D in 99% of all cases. An analogous result was achieved with optical axial length data after suitable transformation of optical path lengths into geometrical distances. CONCLUSIONS: Partial coherence interferometry is a noncontact, user- and patient-friendly method for axial length determination and IOL planning with an accuracy comparable to that of high-precision immersion ultrasound.

Adult↗

Hemispheric stroke following cardiac surgery: a case-control estimate of the risk resulting from ipsilateral asymptomatic carotid artery stenosis.

A case-control study was undertaken to determine if asymptomatic carotid artery stenosis (ACS) is independently associated with ipsilateral hemispheric stroke following cardiac surgery (CS). All CS patients (3069) who were at two hospitals between 1989 and 1994 were reviewed. Cases (31) selected for this study were those with hemispheric stroke within 30 days following CS. Controls (69) were taken from those without hemispheric stroke. Case-control analysis demonstrated that ACS of 50-90% and of 80-90% increased the risk of ipsilateral stroke 5.2-fold (95% confidence interval [CI] = 1.5-16.3, p = 0.01) and 24.3-fold (CI = 2.6-114.9, p = 0.002), respectively. Other variables with significant odds ratios (OR) were age > or =65 years (OR = 4.0, CI = 1.3-10.5, p = 0.01), peripheral vascular disease (OR = 3.4, CI = 1.3-8.8, p = 0.02), hypertension (OR = 3.0, CI = 1.2-7.0, p = 0.02), and female gender (OR = 3.0, CI = 1.2-7.1, p = 0.04). A second conservative analysis for missing data demonstrated a significant association for ACS of 80-90% alone (OR = 13.1, CI = 1.5-60.9, p = 0.01). This association remained significant after multivariate adjustment with propensity score stratification. ACS (80-90%) appears to be independently associated with ipsilateral hemispheric stroke following CS when evaluated against the present study variables. This finding supports the need for a properly conducted prospective natural history study, including an evaluation of aortic arch atherosclerosis, to determine the clinical relevance of this observation.

Aged↗

The impact of positive mood and category importance on crossed categorization effects.

Four studies examined the effect of positive versus neutral affect on preference among potential discussion partners who were members of two in-groups, two out-groups, or both an in-group and an out-group (crossed targets). The importance of targets' category memberships was manipulated by idiographically based selection. Positive affect elevated evaluation of crossed targets with a dominant (differentially important) in-group (Study 1). When categories were made equally important, positive affect had no impact (Studies 2 and 3). Study 4 presented crossed targets with both equally and differentially important group memberships and showed that differential category importance (dominance) is necessary for positive affect to influence judgments about them. These results are explained by the broadened categorization induced by positive affect.

Affect↗

Displaced aggression is alive and well: a meta-analytic review.

Content analysis of 122 social psychology textbooks confirmed that displaced aggression received a surge of attention immediately following J. Dollard, L. W. Doob, N. E. Miller, O. H. Mowrer, and R. R. Sears (1939), but subsequent interest sharply declined. Contemporary texts give it little attention. By contrast, meta-analysis of the experimental literature confirms that it is a robust effect (mean effect size = +0.54). Additionally, moderator analyses showed that: (a) The more negative the setting in which the participant and target interacted, the greater the magnitude of displaced aggression; (b) in accord with N. E. Miller's (1948) stimulus generalization principle, the more similar the provocateur and target, the more displaced aggression; and (c) consistent with the contrast effect (L. Berkowitz & D. A. Knurek, 1969), the intensity of initial provocation is inversely related to the magnitude of displaced aggression.

Aggression↗

The moderating effect of trivial triggering provocation on displaced aggression.

Two studies examined the interaction between the presence or absence of (a) an initial provocation and (b) a subsequent minor triggering action on the part of the target of displaced aggression. Consistent with the triggering event being seen by participants as indeed trivial when administered by itself without prior provocation, exposure to it literally had no impact on aggression toward its source. When previously provoked, however, this subsequent triggering event strongly increased displaced aggression, causing it to reliably exceed both that displayed when there was no antecedent provocation and that elicited by provocation alone. Mediation analyses showed that for participants who had been provoked, subjective feelings of displeasure concerning the triggering event mediated the effect of the trigger on aggression.

Adolescent↗

Determination of major aroma impact compounds in fermented cucumbers by solid-phase microextraction--gas chromatography--mass spectrometry--olfactometry detection.

Purge-and-trap, solid-phase extraction, and solid-phase microextraction-gas chromatography-mass spectrometry (SPME-GC-MS) sample preparation techniques for the analysis of odor impact chemicals in fermented cucumber brine are compared. SPME-GC-MS is coupled with detection frequency olfactometry experiments to determine key impact odor compounds in the brine. The most potent odorants that define the typical characteristic brine aroma are trans-4-hexenoic acid and cis-4-hexenoic acid. Confirmation of key impact odorants in brine is confirmed by recombination experiments.

Cucumis sativus↗

Predicting state Medicaid home and community based waiver participants and expenditures, 1992-1997.

PURPOSE: The study examined trends and predictors of state Medicaid home and community based waiver participants and expenditures from 1992 to 1997 to identify factors of interest to policy makers and clinicians. DESIGN AND METHODS: HCFA Form 372 data were collected from state officials for each waiver for each year. Two separate regression analyses were conducted to examine the effects of sociodemographic, economic, political, policy, and health services on state waiver participants and expenditures. RESULTS: State waiver participants were positively associated with those aged 85 and over, personal income, residential care beds, and inpatient users and negatively with home health regulation and nursing home beds. State waiver expenditures were positively associated with democratic governors, personal income, home health reimbursement methods, Medicaid eligibility, home health agencies, and Medicare home health users. IMPLICATIONS: The factors policy makers might consider changing include increasing the number of residential care beds and home health agencies, removing certificate of need for home health care, using Medicare home health reimbursement methods for Medicaid, and raising the Medicaid eligibility criteria. In some states with low nursing home occupancy rates, reducing the supply of nursing home beds may also be considered. All of these approaches would be controversial and should be based on additional cost-effectiveness analysis.

Age Factors↗

The CD45 tyrosine phosphatase regulates Campath-1H (CD52)-induced TCR-dependent signal transduction in human T cells.

Campath-1H, a humanized mAb undergoing clinical trials for treatment of leukemia, transplantation and autoimmune diseases, produces substantial lymphocyte depletion in vivo. The antibody binds to CD52, a highly glycosylated molecule attached to the membrane by a glycosylphosphatidylinositol anchor. Cross-linked Campath-1H is known to activate T cells in vitro. We have investigated the molecular basis for these effects by comparing the protein tyrosine phosphorylation signals induced by Campath-1H and the CD3 mAb OKT3 in primary T cells, and in CD45(+)TCR(+), CD45(-)TCR(+) and CD45(+)TCR(-) Jurkat subclones transfected with CD52. Our results show that Campath-1H triggers similar tyrosine phosphorylation events as OKT3 in both primary T cells and in the CD45(+)TCR(+) Jurkat sub-clone, albeit at quantitatively lower levels. However, no phospholipase C gamma 1 activation nor calcium signals were detected in response to CD52 ligation. The CD52-mediated induction of protein tyrosine phosphorylation was absolutely dependent upon the expression of both the TCR and the CD45 phosphotyrosine phosphatase at the cell surface. Cross-linking of Campath-1H was essential for signal transduction in all cells investigated. Fluorescence resonance energy transfer was used to demonstrate CD52 homo-association at the cell surface in Jurkat T cells in a TCR- and CD45-independent manner, and CD52-TCR association in CD45(+)TCR(+) cells. We propose a model to explain the activating effects of Campath-1H in which CD52 mAb cross-linking causes the trapping of TCR polypeptides within molecular complexes at the cell surface, thereby inducing signals via the TCR by a process which depends on the CD45-mediated regulation of the p56(lck) and p59(fyn) tyrosine kinases.

Alemtuzumab↗

Evaluation of the LiPA MYCOBACTERIA assay for identification of mycobacterial species from BACTEC 12B bottles.

The LiPA MYCOBACTERIA (Innogenetics NV, Ghent, Belgium) assay was used to identify mycobacterial isolates using culture fluid from positive BACTEC 12B bottles. The LiPA method involves reverse hybridization of a biotinylated mycobacterial PCR fragment, a 16 to 23S rRNA spacer region, to oligonucleotide probes arranged in lines on a membrane strip, with detection via biotin-streptavidin coupling by a colorimetric system. This system identifies Mycobacterium species and differentiates M. tuberculosis complex, M. avium-M. intracellulare complex, and the following mycobacterial species: M. avium, M. intracellulare, M. kansasii, M. chelonae group, M. gordonae, M. xenopi, and M. scrofulaceum. The mycobacteria were identified in the laboratory by a series of tests, including the Roche AMPLICOR Mycobacterium tuberculosis (MTB) test, the Gen-Probe ACCUPROBE, and a PCR-restriction fragment length polymorphism (PCR-RFLP) analysis of the 65-kDa heat shock protein gene. The LiPA MYCOBACTERIA assay detected 60 mycobacterium isolates from 59 patients. There was complete agreement between LiPA and the laboratory identification tests for 26 M. tuberculosis complex, 9 M. avium, 3 M. intracellulare complex, 3 M. kansasii, 4 M. gordonae, and 5 M. chelonae group (all were M. abscessus) isolates. Three patient samples were LiPA positive for M. avium-M. intracellulare complex, and all were identified as M. intracellulare by the PCR-RFLP analysis. Seven additional mycobacterial species were LiPA positive for Mycobacterium spp. (six were M. fortuitum, and one was M. szulgai). The LiPA MYCOBACTERIA assay was easy to perform, and the interpretation of the positive bands was clear-cut. Following PCR amplification and gel electrophoresis, the LiPA assay was completed within 3 h.

Bacterial Typing Techniques↗