Search PubMed⌕ Search

Biomedical subjects

N Miller

Publications and source records attributed to N Miller.

At least 55 records · Page 3Linked to original sources
PubMed2000

Reinforcing variability in adolescents with autism.

Five adolescents with autism, 5 adult control participants, and 4 child controls received rewards for varying their sequences of responses while playing a computer game. In preceding and following phases, rewards were provided at approximately the same rate but were independent of variability. The most important finding was that, when reinforced, variability increased significantly in all groups. Reinforced variability could provide the necessary behavioral substrate for individuals with autism to learn new responses.

Adolescent↗
PubMed2000

MEDLINEplus: building and maintaining the National Library of Medicine's consumer health Web service.

MEDLINEplus is a Web-based consumer health information resource, made available by the National Library of Medicine (NLM). MEDLINEplus has been designed to provide consumers with a well-organized, selective Web site facilitating access to reliable full-text health information. In addition to full-text resources, MEDLINEplus directs consumers to dictionaries, organizations, directories, libraries, and clearinghouses for answers to health questions. For each health topic, MEDLINEplus includes a preformulated MEDLINE search created by librarians. The site has been designed to match consumer language to medical terminology. NLM has used advances in database and Web technologies to build and maintain MEDLINEplus, allowing health sciences librarians to contribute remotely to the resource. This article describes the development and implementation of MEDLINEplus, its supporting technology, and plans for future development.

Community Participation↗
PubMed2000

Prosthetic above-knee femoropopliteal bypass grafting: five-year results of a randomized trial.

PURPOSE: This trial was designed to identify factors affecting patency rates of primary prosthetic above-knee femoropopliteal bypass grafts at 5 years. METHODS: A multi-institutional, prospective trial randomized 240 patients to compare patency rates of Gore-tex and Hemashield above-knee femoropopliteal bypass grafts at 5 years. Univariate comparisons of patency between levels of each prognostic variable were made with the Kaplan-Meier method. Variables that had a univariate P value less than.25 or those known to be important were submitted to a Cox regression analysis. RESULTS: The patient survival rate at 5 years was 59.4%. There were no differences in primary or secondary patency rates at 5 years between the two graft materials (primary, 45% vs 43% and secondary, 68% vs 68%). The risk for graft occlusion was significantly increased for patients younger than 65 years (2.1; P =.001) and for grafts with a diameter less than 7 mm (1.65; P =.0219). Variables with no apparent independent effect on patency rates were smoking status, runoff, diabetes mellitus, sex, presenting symptoms, and postoperative treatment with aspirin or Coumadin. Noninvasive test results were not predictive of subsequent graft function. CONCLUSION: Although the type of prosthetic used for above-knee femoropopliteal bypass grafts does not affect 5-year patency rates, age and graft size do influence results. These factors should be considered before a prosthetic bypass grafting procedure. Furthermore, these data should serve as a contemporary standard, with which evolving and conventional procedures can be compared.

Aged↗
PubMed2000

Trends in chronic obstructive pulmonary disease mortality.

This study examines the mortality trends for chronic obstructive pulmonary disease (COPD) among whites and African Americans in Missouri from 1980-1996. Data from the Missouri Center for Health Information Management and Epidemiology were used to calculate mortality rates. Missouri's COPD deaths rose 40.6% from 1980-1996. Projections through the year 2006 predict continued escalation in rates. Much of the growth in COPD can be attributed to heavy tobacco use in the population.

Adolescent↗
PubMed2000

Histologic analysis of a fractured implant: a case report.

This study presents the histologic analysis of an implant retrieved 14 months after loading because of a fracture in the collar region. The implant (Biovent) was removed with part of the periimplant tissues, and the block was prepared using cutting and grinding equipment to obtain 3 sections approximately 30 microns thick. The examination evidenced a high degree of osseointegration, with a bone-to-implant contact of 74% +/- 13%. The lamellar bone was dense and in close relation with the hydroxyapatite coating of the implant. The connection between the 0.4-mm hydroxyapatite coating and the metal was always very tight. The thickness of the metal at the break point was assessed to be 1.6 mm. Besides the relative weakness of the metal at the neck of the implant, other possible causes of failure are discussed.

Biocompatible Materials↗
PubMed1999

Frequent loss of imprinting of PEG1/MEST in invasive breast cancer.

The human PEG1 gene is a newly identified imprinted gene on 7q32. Genetic aberrations of this chromosomal region are often detected in invasive breast carcinomas. In this study, we show monoallelic PEG1 expression in normal breast tissue, indicating the presence of a functional imprint, and more importantly, we demonstrate loss of imprinting (LOI) in all of seven informative invasive breast carcinomas. In contrast to this, in one case of atypical ductal hyperplasia (ADH) found in residual breast, imprinting was maintained. This raises the possibility that aberrant imprinting of PEG1 may be involved in the progression from hyperplasia to invasive breast cancer.

Alleles↗
PubMed1999

Shiga-like toxin-1 receptor on human breast cancer, lymphoma, and myeloma and absence from CD34(+) hematopoietic stem cells: implications for ex vivo tumor purging and autologous stem cell transplantation.

The ribosome-inactivating protein, Shiga-like toxin-1 (SLT-1), targets cells that express the glycolipid globotriaosylceramide (CD77) on their surface. CD77 and/or SLT-1 binding was detected by flow cytometry and immunocytochemistry on lymphoma and breast cancer cells recovered from biopsies of primary human cancers as well as on B cells or plasma cells present in blood/bone marrow samples of multiple myeloma patients. Breast cancer cell lines also expressed receptors for the toxin and were sensitive to SLT-1. Treatment of primary B lymphoma, B-cell chronic lymphocytic leukemia, and myeloma B or plasma cells with SLT-1-depleted malignant B cells by 3- to 28-fold, as measured by flow cytometry. Depletion of myeloma plasma cells was confirmed using a cellular limiting dilution assay followed by reverse transcriptase-polymerase chain reaction analysis of clonotypic IgH transcripts, which showed a greater than 3 log reduction in clonotypic myeloma cells after SLT-1 treatment. Receptors for the toxin were not detected on human CD34(+) hematopoietic progenitor cells (HPC). HPC were pretreated with a concentration of SLT-1 known to purge primary malignant B cells and cultured for 6 days. The number of HPC was comparable in toxin-treated and untreated cultures. HPC were functionally intact as well. Colony-forming units (CFU) were present at an identical frequency in untreated and SLT-1 pretreated cultures, confirming that CFU escape SLT-1 toxicity. The results suggest the ex vivo use of SLT-1 in purging SLT-1 receptor-expressing malignant cells from autologous stem cell grafts of breast cancer, lymphoma, and myeloma patients.

Antibodies, Monoclonal↗
PubMed1999

Male breast carcinoma: a review of 229 patients who presented to the Princess Margaret Hospital during 40 years: 1955-1996.

BACKGROUND: A single-institution review of clinical presentation, treatment, and outcome of male breast carcinoma was conducted. METHODS: Data obtained by chart review of 229 cases were analyzed with respect to clinical presentation, treatment choice, significant prognostic factors, and survival. The patients were analyzed both as a single cohort and as four cohorts grouped according to decade of diagnosis. RESULTS: Presentation occurred at a median age of 63 years, most often with a self-detected lump. Pathology consisted of subtypes similar to those of female breast carcinoma. The majority of tumors were larger than 2 cm in greatest dimension. Lymph node status, hormone receptors, and histologic and nuclear grade were underreported. Primary, adjuvant, and advanced disease treatment practices were reviewed over time. The 5-year disease free survival (DFS), overall survival (OS), and local control were 47%, 53%, and 91%, respectively. No difference in outcome by decade of diagnosis was observed. Negative lymph nodes and adjuvant hormone treatment predicted for better DFS and OS. Younger age and Stage 0 also predicted for better OS. CONCLUSIONS: Compared with data from female breast carcinoma patients, 5-year OS for this series was low; however, when these patients were separated by lymph node status, survival was similar for those with axillary lymph node metastases. Despite a change in standard primary surgical treatment and an increased use of chemotherapy and hormone therapy over the study period, no difference in outcome was observed among these males. In the absence of prospective, randomized clinical trials, collection of comprehensive data on the presentation and management of male breast carcinoma may help to optimize clinical care.

Adult↗
PubMed1999

The polyphenolic content of fruit and vegetables and their antioxidant activities. What does a serving constitute?

Analysis of the major flavone, flavonol, anthocyanidin and hydroxycinnamic acid constituents (and their glycosides) of onion, tomato, egg plant and apple has been undertaken and the antioxidant activities of the phenolic extracts determined. The major phenolic antioxidant components of egg plant are chlorogenic acid in the flesh and a delphinidin conjugate in the skin. In the case of apple, the major phenolic antioxidants detected are chlorogenic acid, procyanidins/catechin compounds, rutin and phloridzin. Quercetin glycosides are well-known to be the major phenolic components of onion. Assessment of the antioxidant activities of a serving of 100g fresh weight fruit, vegetable and comparison with previously reported findings for 150 ml beverage (500 ml portion in the case of beer), expressed in micromol Trolox equivalents show that the antioxidant activities of 1 glass (150 ml) red wine equivalent to 12 glasses white wine equivalent to 2 cups of tea equivalent to 4 apples equivalent to 5 portions of onion equivalent to 5.5 portions egg plant equivalent to 3.5 glasses of blackcurrant juice equivalent to 3.5 (500 ml) glasses of beer equivalent to 7 glasses of orange juice equivalent to 20 glasses of apple juice (long life).

Anthocyanins↗
PubMed1999

Trends in Missouri lung cancer rates.

This study presents trend analysis of Missouri lung cancer incidence and mortality, and makes comparisons to U.S. rates. Utilizing 1985-1992 data from the Missouri Cancer Registry, we calculated incidence rates by disease diagnosis year. Missouri Center for Health Information Management and Epidemiology data were used to calculate 1980-1996 mortality rates. Missouri's overall yearly lung cancer incidence rate increased from 60.5 to 62.5 per 100,000 during 1985-1992, while lung cancer mortality increased 25% from 1980-1996. The best method to reduce Missouri's rates of lung cancer is tobacco-use prevention and cessation.

Adult↗
PubMed1999

Smoking initiation and escalation in early adolescent girls: one-year follow-up of a school-based prevention intervention for minority youth.

OBJECTIVE: To examine the effectiveness of a drug abuse prevention program in reducing the initiation and escalation of smoking in a sample of predominantly minority junior high school girls. METHODS: The 15-session prevention program teaches social resistance skills within the context of a broader intervention designed to promote general personal and social competence skills, and is implemented in the seventh grade. Smoking rates in girls from 29 New York City public schools who received the program (n = 1,278) were compared to smoking rates in a control group of girls (n = 931) who did not. RESULTS: Those who participated in the program were less likely to initiate smoking relative to controls, due in part to significant program effects on smoking intentions, smoking knowledge, perceived peer and adult smoking norms, drug refusal skills, and risk taking. Experimental smokers in the intervention group were less likely to escalate to monthly smoking relative to controls, due in part to significant program effects on smoking intentions. CONCLUSION: A school-based drug abuse prevention approach previously found to be effective among white youth significantly reduced smoking initiation and escalation among urban minority girls.

Adolescent↗
PubMed1998

Random mutagenesis of human estrogen receptor ligand binding domain identifies mutations that decrease sensitivity to estradiol and increase sensitivity to a diphenol indene-ol compound: basis for a regulatable expression system.

We have used low fidelity polymerase chain reaction amplification to generate mutations in the human estrogen receptor ligand binding domain (LBD). Screening of libraries of mutants in yeast revealed a variety of phenotypic changes including decreased responsiveness to estradiol and increased responsiveness to synthetic compounds. Identification of the mutations responsible for these phenotypic changes indicated discrete regions of the LBD that are important for human estrogen receptor function. Cumulative rounds of mutagenesis and screening allowed us to produce a mutant estrogen receptor that was of reversed specificity as compared with the wild type LBD, in that it was more responsive to a diphenol indene-ol than to estradiol. This mutant may form the basis of a useful regulatable expression system in mammalian cells.

Amino Acid Sequence↗
PubMed1998

Venous duplex scanning for unilateral symptoms: when do we need a contralateral evaluation?

OBJECTIVES: Determine the need for bilateral duplex scanning (DS) in patients with unilateral symptoms of acute DVT of the leg. DESIGN: Prospective study. MATERIALS: One thousand, one hundred and sixty-one consecutive patients with recent unilateral symptoms of pain or swelling. METHODS: Bilateral DS were performed and demographic data including risk factors for DVT were entered into a computerised database. RESULTS: Of the 250 cases (22%) of acute DVT, thrombus was confined to the symptomatic limb in 80% (200/250) and to the asymptomatic limb (AL) in 5% (12/250), while bilateral DVT was found in 15% (38/250). The management was not altered by the contralateral DS findings in any patient with bilateral thrombus. Ten of the 12 cases of DVT confined to the AL were localised to the infrapopliteal level; advanced malignancy, recent joint surgery or hypercoagulability were noted in nine patients, including all those requiring treatment. CONCLUSIONS: In the presence of unilateral symptoms of DVT, we recommend DS of the symptomatic extremity only; bilateral examination should be confined to patients with normal duplex findings in the symptomatic limb following recent joint surgery, or in the presence of advanced malignancy or hypercoagulability. Bilateral DS would therefore be required in approximately 11% of cases with unilateral symptoms of DVT.

Acute Disease↗
PubMed1998

Guided bone regeneration for immediate non-submerged implant placement using bioabsorbable materials in Beagle dogs.

The aim of the present study was to evaluate the combined application of different bioabsorbable materials for healing of residual peri-implant defects after placement of non-submerged implants into fresh extraction sockets. Second and third mandibular premolars were extracted from 10 Beagle dogs, the coronal part of the distal sockets were surgically enlarged and this was followed by immediate placement of specially designed hollow-screw non-submerged dental implants. For each animal, the coronal peri-implant defects were further treated with one of the 4 following procedures: 1) no treatment, control site; 2) grafting with porous hydroxyapatite (HA); 3) collagen membrane tightly secured around the implant and over the defect and 4) grafting with HA covered with a collagen membrane. After 16 weeks of healing, specimens were removed from the mandibule and prepared for a histomorphometric evaluation. The bone-to-implant contact length (BIC) was measured and compared amongst the different treatment modalities. In the defect area, the irregular bone regeneration was similar between all the treatment procedures (P > 0.10). In the sites covered with a collagen membrane alone, the total BIC (47%) was greater than in control sites (28.7%, P < 0.05) or sites grafted with HA (22.2%, P < 0.02). Total BIC in sites treated with the HA-membrane combination (43%) was only significantly different from sites treated with HA (P < 0.05). It is concluded that the use of bioabsorbable materials results in a limited increase of osseointegration when used in conjunction with immediate placement of non-submerged implants, although the principle of the one stage surgical approach can be maintained.

Absorbable Implants↗
PubMed1998

Conversation analysis of communication breakdown after closed head injury.

This single case study investigated the use of Conversation Analysis (CA) in assessing pragmatic language difficulties after closed head injury (CHI). The aim was to see if CA captures the types of communication breakdown observed after CHI and whether results from CA can be directly related to scores on formal tests more typically applied after CHI. The results suggested that CA was a sensitive tool for identifying and investigating pragmatic deficits in this case. It facilitated an exploration of whether language impairments identified on formal tests manifest themselves in functional communication; it revealed how different interlocutors adapt to these language difficulties in conversation and also explained why some conversational partners were more successful than others. Considered together, formal test results and CA insights facilitated an in-depth analysis into the precise nature of the communicative impairments of the speaker in this exploratory study, suggesting that CA is a promising approach to the assessment of pragmatic impairments in the CHI population.

Adaptation, Psychological↗
PubMed1998

Disseminated miliary tuberculosis of the skin in patients with AIDS: report of four cases.

We present clinical, bacteriologic, and pathological findings for four patients with AIDS and cutaneous miliary tuberculosis. All patients had generalized tuberculosis with hematogenous dissemination to multiple organs including the skin. Microscopic examination of the skin lesions revealed ill-formed or no granulomata, extensive necrosis, and numerous acid-fast bacilli. Mycobacterium tuberculosis was detected in the skin lesions by cultures for three patients and by polymerase chain reaction for one. Three of the isolates were resistant to at least isoniazid and rifampin, and one was susceptible to these drugs. The outcome was rapidly fatal for the three patients with multidrug-resistant tuberculosis. This report draws attention to the reappearance of a once-rare manifestation of disseminated tuberculosis which, in the setting of advanced human immunodeficiency virus disease, may offer the first indication of infection with multidrug-resistant M. tuberculosis and a poor prognosis.

Acquired Immunodeficiency Syndrome↗
PubMed1998

Blindness as a complication of Le Fort osteotomies: role of atypical fracture patterns and distortion of the optic canal.

Blindness in patients suffering maxillofacial trauma is usually caused by optic nerve or optic canal injuries. It is, however, an uncommon complication of facial trauma, with a reported incidence of only 3 to 5 percent. This incidence drops dramatically when fractures are performed in the controlled situation of orthognathic surgery. Given the rarity of ophthalmic complications after traumatic Le Fort I injuries, it is not surprising that few cases have been reported after orthognathic surgery. In this article, three cases of visual loss or skull base injury after elective Le Fort I osteotomy are described. All of these cases were presumably straightforward surgically and were performed by experienced surgeons. The literature is reviewed and the pathomechanics of each injury are experimentally explored in a cadaver model. To determine the presence of increased pressure on the optic nerve, optic canal deformation, or fractures extending to the skull base, two separate experiments were devised. In the first experiment, a pressure transduction system was used to document any significant forces that may be directly transmitted to the contents of the optic canal during pterygomaxillary separation. Then tested was the hypothesis that a stepped or tapered osteotomy will allow for a more predictable pterygomaxillary fracture. One of five cadaver specimens in group 1 demonstrated a transient increase in the right optic canal pressure during down-fracture of the maxilla. This change was less than 10 mmHg, and its duration was less than 5 seconds. The canal pressure returned to baseline with the completion of the fracture. In group 2, there was no documented pressure change with either osteotomy technique. Of note, in group 2, all specimens undergoing standard Le Fort osteotomy demonstrated uncontrolled propagation of the fracture lines superiorly in the pterygoid bones. The uncontrolled and unpredictable nature of pterygomaxillary disjunction may result in the extension of fractures to the skull base or the generation of deforming forces to the optic canal may compress or injure the optic nerve and its circulation. It is proposed that a stepped or tapered osteotomy will generate a more controlled pterygomaxillary separation during orthognathic surgery and may reduce the risk of devastating ophthalmologic complications.

Adolescent↗