Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Computer Peripherals”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,747 records · Page 97Linked to original sources
PubMed1990

Specific high-affinity binding of peripheral benzodiazepine receptor ligands to brain tumors in rat and man.

Two types of benzodiazepine receptors have been identified in mammalian tissues: a central type which is localized to neuronal elements in the brain, and a peripheral type which is present on glial cells and in tissues outside the central nervous system such as kidney. The authors report an increase in specific binding of peripheral benzodiazepine receptor ligands in certain human brain tumors using computer assisted quantitative image analysis of autoradiograms. Higher densities of binding sites to a 3H-labeled selective peripheral benzodiazepine ligand, PK11195 [1-(2-chlorophenyl-N-methyl-N-(1-methylpropyl)-3-isoquinoline carboxamide] were observed in human gliomas as the malignancy of these tumors increased. Specific binding was also present in some non-glial tumors but little binding was demonstrated in necrotic tissue or normal brain. In in vitro binding studies in rats, there was a significant increase in Bmax (1089.3 +/- 232.2 fmol/mg tissue) in C6 glial tumors and LK Walker 256 metastatic tumors (924.2 +/- 183.7) compared with normal brain (62.1 +/- 12.8 fmol/mg tissue). Binding affinities were, however, similar (Kd = 2.09, 2.17, and 2.04 nmol/l, respectively). These findings suggest that the number of peripheral benzodiazepine receptors are increased in brain tumors. These receptors could be utilized in positron emission tomography to image brain tumors.

Animals↗
PubMed1997

Factors affecting the radiologic appearance of peripheral bronchogenic carcinomas.

The use of high-resolution computed tomography and magnetic resonance imaging have allowed the detailed description of morphologic findings associated with lung cancer. In particular, the desmoplastic response of lung tissue to tumor growth has not been adequately described. This article reviews roentgenologic and pathologic correlations of primary lung carcinomas. An irregular or indistinct tumor margin may be caused by tumor infiltration, an irregular desmoplastic response to the tumor growth, or irregular contraction in the central portion of the tumor. Solid tumor growth, on the other hand, may be associated with a well-defined tumor margin, with or without displacement of adjacent anatomical structures.

Adenocarcinoma↗
PubMed1994

The value of limited resection for "clinical" stage I peripheral non-small cell lung cancer in poor-risk patients: comparison of limited resection and lobectomy by a computer-assisted matched study.

AIM: A computer-assisted retrospective matched study was devised to compare limited resection and lobectomy for non-small cell lung cancer. METHODS: Of 353 patients undergoing operation for "clinical" stage I peripheral non-small cell lung cancer, 16 patients undergoing limited resection (because of poor risk) could be matched satisfactorily with 16 patients undergoing lobectomy (as a standard procedure) on the basis of age, sex, histology, tumor location, and tumor size with computer assistance. RESULTS: No hospital death was observed in the 32 patients. Three of the 16 limited resection patients (19%) developed local recurrence in the same lobe. The 5-year survival rate was 55.5% for limited resection and 73.7% for lobectomy (P = not significant). For tumors more than 2.0 cm in diameter, 3-year survival rate was significantly lower in the limited resection group than in the lobectomy group: 34.3% versus 85.7%, P < 0.05. For adenocarcinoma, limited resection seemed to be more unfavorable than lobectomy: 5-year survival rate, 34.3% versus 75.0%, P = 0.07. CONCLUSIONS: Limited resection offered a good survival rate without hospital death for poor-risk patients; however, lobectomy should be performed for good-risk patients.

Aged↗
PubMed1997

Mapping the peripheral benzodiazepine receptor binding site by conformationally restrained derivatives of 1-(2-chlorophenyl)-N-methyl-N-(1-methylpropyl)-3- isoquinolinecarboxamide (PK11195).

A synthetic-computational approach to the study of the binding site of peripheral benzodiazepine receptor (PBR) ligands related to 1-(2-chlorophenyl)-N-methyl-N-(1-methylpropyl)-3-isoquinolinecarboxam ide (PK11195, 1) within their receptor has been developed. A wide series of conformationally restrained derivatives of 1 has been designed with the aim of probing the PBR binding site systematically. The synthesis of these compounds involves palladium-catalyzed coupling and amidation as the key steps. Twenty-nine rigid and semirigid derivatives of 1 were tested in binding studies using [3H]-1, and most of these showed PBR affinities in the nanomolar range. The essential role of the carbonyl moiety as a primary pharmacophoric element in the recognition by and the binding to PBR has been confirmed, and the restricted range of the carbonyl orientations, which characterizes the most potent ligands, points to a specific hydrogen-bonding interaction, mainly directed by the geometrical factors, when the electronic ones are fulfilled. Moreover, the fundamental importance of the short-range dispersive interactions in the modulation of the binding affinity and, hence, in the stabilization of the ligand-receptor complex, emerged from the QSAR models reported.

Animals↗
PubMed2000

Monte Carlo assessment of computed tomography dose to tissue adjacent to the scanned volume.

The assessment of the radiation dose to internal organs or to an embryo or fetus is required on occasion for risk assessment or for comparing imaging studies. Limited resources hinder the ability to accurately assess the radiation dose received to locations outside the tissue volume actually scanned during computed tomography (CT). The purpose of this study was to assess peripheral doses and provide tabular data for dose evaluation. Validated Monte Carlo simulation techniques were used to compute the dose distribution along the length of water-equivalent cylindrical phantoms, 16 and 32 cm in diameter. For further validation, comparisons between physically measured and Monte Carlo-derived air kerma profiles were performed and showed excellent (1% to 2%) agreement. Polyenergetic x-ray spectra at 80, 100, 120, and 140 kVp with beam shaping filters were studied. Using 10(8) simulated photons input to the cylinders perpendicular to their long axis, line spread functions (LSF) of the dose distribution were determined at three depths in the cylinders (center, mid-depth, and surface). The LSF data were then used with appropriate mathematics to compute dose distributions along the long axis of the cylinder. The dose distributions resulting from helical (pitch = 1.0) scans and axial scans were approximately equivalent. Beyond about 3 cm from the edge of the CT scanned tissue volume, the fall-off of radiation dose was exponential. A series of tables normalized at 100 milliampere seconds (mAs) were produced which allow the straight-forward assessment of dose within and peripheral to the CT scanned volume. The tables should be useful for medical physicists and radiologists in the estimation of dose to sites beyond the edge of the CT scanned volume.

Computer Simulation↗
PubMed2001

Synthetic peptides induce a cytotoxic response against human papillomavirus type-18.

OBJECTIVES: Over 90% of cervical carcinomas express human papillomavirus (HPV) E6 and E7 proteins. These unique antigens are ideal targets for the development of cytotoxic T-lymphocytes (CTL) for antitumor immunotherapy. In this study we identify peptides from HPV-18 E6 and E7 proteins that bind to HLA class I molecules. We further show that these peptides are able to induce peptide-specific CTL from an HLA-A2-positive (+) peripheral blood donor in vitro. METHODS: A computer-assisted algorithm was devised to identify peptides from HPV-18 E6 and E7 proteins that bind to HLA-A2 molecules. Peptides that were predicted to bind were synthesized and their binding activity was determined. HLA-A2(+) irradiated stimulator cells pulsed with HPV-18 peptides were incubated with HLA-A2(+) peripheral blood mononuclear cells. Cytotoxicity assays were performed to assess specific cell lysis. RESULTS: Of 295 possible sequences, the computer-assisted algorithm predicted 10 peptides that would have a high probability of binding to HLA-A2. The 4 strongest binding peptides were analyzed for their ability to induce cytotoxic cells against HPV-18 peptide-pulsed targets. Two of the peptides induced significant lysis. CONCLUSIONS: There are limited data on peptide-based immunotherapy for HPV-18(+) tumors. The combination of our computer-assisted algorithm and binding assay permits rapid selection of potential CTL epitopes. We identified two peptides that were able to induce peptide-specific lysis. These two epitopes are candidates for a peptide-based vaccine against HPV-18(+) tumors. The model described has broad applications and can be used in the development of immunotherapy for other types of cancers.

Binding Sites↗
PubMed1996

The effect of photorefractive keratectomy on the corneal endothelium.

PURPOSE: The authors prospectively investigated the effect of excimer laser photorefractive keratectomy (PRK) for myopia on the corneal endothelium. METHODS: Quantitative computer-assisted morphometric analysis of central and peripheral corneal endothelial cells was performed on 142 myopic eyes before and at 3 months, 1 year, and 2 years after PRK. The mean age of the subjects was 37 years (range, 21-66 years). Ninety-one (64%) of them had a history of contact lens wear. Mean attempted correction was -3.9 diopters (range, -1.6 to -6.0 diopters). RESULTS: The mean preoperative endothelial cell density was 2660 cells/mm2 centrally and 2776 cells/mm2 peripherally. There was no change in central endothelial cell density at any of the postoperative examinations. The peripheral cell density decreased 4.1% (P = 0.003) at 3 months and 6.2% (P = 0.0001) at 1 year. However, the peripheral cell density was not significantly different from the preoperative value at 2 years. The peripheral coefficient of variation of cell size was 7.8% lower 2 years postoperatively than it was preoperatively, and this improvement was attributable to cessation of contact lens wear after PRK. The decrease in peripheral endothelial cell density at 1 year correlated with the amount of attempted correction, but there was no correlation between attempted correction and the change in central or peripheral endothelial cell density 2 years postoperatively. CONCLUSION: For the correction of up to 6.0 D of myopia, PRK causes no detectable changes in central corneal endothelial cell density, but it does cause a transient, modest loss of peripheral corneal endothelial cells at 1 year. Variations in endothelial cell shape caused by contact lens wear resolve after PRK.

Adult↗
PubMed1993

Video-assisted thoracoscopic wedge resection of T1 lung cancer in high-risk patients.

OBJECTIVE: This study assessed the reliability and safety of VATR for treatment of peripheral T1 lung cancer in high-risk patients. SUMMARY BACKGROUND DATA: Surgical resection is the best therapy for stage I lung cancer. Patients with poor cardiopulmonary status or those who are elderly (> 75 years of age) are considered to be at high risk from thoracotomy and are frequently referred for radiation therapy or expectant palliative management. Data from previous studies suggest that survival with wedge resection is similar to that with lobectomy. The authors propose VATR, which is minimally invasive, as a therapeutic option in patients considered to be at high risk for resection by thoracotomy. METHODS: Between November 1990 and November 1992, more than 400 thoracoscopic lung resections were performed. Thirty patients with poor pulmonary function (forced expiratory volume FEV1] < 1 L or < 35% predicted; arterial oxygen tension [PaO2] < 60 mmHg on room air; diffusion capacity [DCO] < 40%) underwent 31 VATRs (1 patient had a staged procedure for bilateral synchronous lung cancers). All patients had T1 peripheral lesions with no bronchoscopically visible lesions. Computed tomography of the chest revealed no evidence of mediastinal disease in all patients. RESULTS: Patients had a mean FEV1 value of 0.9 L (38% predicted) and a mean age of 71 years. Tumors were located in left upper lobe (LUL) in 13 patients, in right lower lobe (RLL) in 7 patients, in right upper lobe (RUL) in 6 patients, in left lower lobe (LLL) in 4 patients, and in right middle lobe (RML) in 1 patient. Computed tomography-guided wire localization, methylene blue surface injection, and intraoperative ultrasonography were used to assist in defining difficult lesions. All lesions were successfully resected without converting to thoracotomy. One patient died on the 34th postoperative day of myocardial infarction (operative mortality rate of 3%). Five patients had prolonged air leaks (< 5 days), with a median chest tube time of 3 days. Two patients experienced pneumonia. CONCLUSION: The authors concluded that VATR is a safe and reliable procedure for treatment of peripheral T1 lung cancer in high-risk patients. Long-term follow-up will be required to determine the efficacy of this procedure regarding survival and locoregional recurrence.

Aged↗
PubMed2006

Nontuberculous mycobacteria in bronchiectasis: Prevalence and patient characteristics.

The aim of the current study was to investigate the prevalence and clinical associations of nontuberculous mycobacteria (NTM) in a well-characterised cohort of patients with adult-onset bronchiectasis. The sputum of all patients attending a tertiary referral bronchiectasis clinic between April 2002 and August 2003 was examined for mycobacteria as part of an extensive diagnostic work-up. NTM-positive patients subsequently had further sputa examined. A modified bronchiectasis scoring system was applied to all high-resolution computed tomography (HRCT) scans from NTM-positive patients, and a matched cohort without NTM. Out of 98 patients attending the clinic, 10 had NTM in their sputum on first culture; of those, eight provided multiple positive cultures. Three patients were treated for NTM infection. A higher proportion of NTM-positive than -negative patients were subsequently diagnosed with cystic fibrosis (two out of nine versus two out of 75). On HRCT scoring, more patients in the NTM-positive group had peripheral mucus plugging than in the NTM-negative group. In the current prospective study of a large cohort of patients with bronchiectasis, 10% cultured positive for nontuberculous mycobacteria in a random clinic sputum sample. Few clinical parameters were helpful in discriminating between groups, except for a higher prevalence of previously undiagnosed cystic fibrosis and of peripheral mucus plugging on high-resolution computed tomography in the nontuberculous mycobacteria group.

Aged↗
PubMed1990

Optic disk swelling with peripheral neuropathy, organomegaly, endocrinopathy, monoclonal gammopathy, and skin changes (POEMS syndrome).

We reviewed charts of patients seen at Mayo Clinic Rochester and Mayo Clinic Jacksonville to determine the importance and frequency of optic disk swelling in patients with peripheral neuropathy, organomegaly, endocrinopathy, monoclonal gammopathy, and skin changes (POEMS syndrome). A computer search identified 148 patients who were classified as having a monoclonal gammopathy and peripheral neuropathy. A review of the 148 charts disclosed that 11 patients had POEMS syndrome. Eight of these 11 patients had optic disk swelling identified by an ophthalmologist. In all eight patients, optic disk swelling was either the initial sign or was present the first time we saw the patient. Optic disk swelling may be an early sign in POEMS syndrome.

Adult↗
PubMed1992

Impact of dialysis modality on body composition in patients with end-stage renal disease.

Loss of muscle mass and altered body fat distribution (i.e. increased central fat stores in the presence of normal peripheral fat stores) have been reported in patients on hemodialysis (HD), when compared to normal volunteers. Whether treatment of end-stage renal disease (ESRD) with continuous ambulatory peritoneal dialysis (CAPD) would alter body composition in a different manner than HD is unknown. To answer this question, two groups (n = 11 each) of male patients with ESRD (matched for age, residual renal function, body weight and body height as well as physical activity) were studied. Muscle mass and body fat distribution were assessed using computed tomography. Mid-thigh muscle area, peripheral and central fat stores were similar between the two groups of dialysis patients. In both patient groups muscle mass and fat stores were independent of duration of dialysis, age, daily protein intake and residual renal function. In CAPD-patients mid-thigh muscle area was correlated with plasma albumin (r = 0.56, p < 0.05), while serum cholesterol level was correlated with mediastinal fat area (r = 0.81, p < 0.01). The present results indicate that both treatment modalities of ESRD (HD vs CAPD) result in similar changes of body composition. Despite continuous glucose loading in CAPD-patients, neither central nor peripheral fat stores are increased in these subjects compared with HD treated patients.

Adipose Tissue↗
PubMed1987

Computers and occupational therapy.

Survey data were collected from a sample of 298 occupational therapy department directors on (a) department demographics; (b) availability of micro- or macrocomputers; (c) types of hardware, software, and peripheral devices used; (d) major purposes and functions for computers; and (e) major factors regarding choice of computers and equipment or factors most influential in the nonuse of computers. Usable questionnaires were returned from 238 or 80% of the sample. Thirty-five percent of the respondents had access to microcomputers in their work setting; however, only 11% actually had them in their occupational therapy department. The study also noted the versatility and adaptability of the computer as used in occupational therapy and discussed common limitations in its use.

Computers↗
PubMed2001

Early clinical experience with color three-dimensional intravascular ultrasound in peripheral interventions.

PURPOSE: To report early clinical experiences with color 3-dimensional intravascular ultrasound (3-D IVUS) in assisting peripheral interventions. TECHNIQUE: A 3.5-F, 20-MHz IVUS catheter that utilizes ChromaFlo computer software to demonstrate blood flow in color was evaluated in over 100 peripheral interventions. ChromaFlo captures up to 30 conventional IVUS frames every second and generates "real-time" imaging. The software compares sequential axial IVUS images and interprets any differences in the position of echogenic blood particles, which are displayed as colorized flow in axial or 3-D renderings. CONCLUSIONS: ChromaFlo-enhanced IVUS demonstrates colorized blood flow inside the vessel lumen, which is helpful in distinguishing echolucent disease from luminal blood flow and can also be used to perform peripheral interventions in patients with renal failure or allergy, avoiding the use of contrast media.

Catheterization↗
PubMed1989

Computed tomography of rheumatologic disorders.

Diseases of the spine and peripheral joints can be diagnosed noninvasively by this revolutionary imaging modality. CT has retrospectively demonstrated superiority over myelography and other imaging techniques in delineating various pathologic conditions--e.g., trauma, neoplasm, and infection--as well as arthropathy. Specific technical approaches are described in detail.

Age Factors↗
PubMed1980

[Minimum phase model of a dynamic spectral analysis of sounds at the periphery of hearing].

The model consists of independent frequency-channels the amplitude-frequency characteristics (AFC) of which are assigned by the investigator. The phase characteristics are computed. Concrete minimum-phase model is described and illustrated. The temporal and frequency characteristics of this model are consistent with experimental data on peripheral auditory system. The AFC can be easily reformed, so the model is convenient for investigation of functional models of peripheral auditory analysis.

Computers↗
PubMed2003

Ischiogluteal bursitis: multimodality imaging findings.

Ischiogluteal bursitis is a rare, infrequently recognized condition. Two cases of ischiogluteal bursitis in an 80-year-old man and a 75-year-old woman are presented. Both patients presented with a painful buttock mass. Contrast-enhanced multiplanar reconstruction computed tomography scans revealed a lesion with peripheral enhancement inferior to the ischial tuberosity. Magnetic resonance imaging revealed a lesion with low or intermediate signal intensity on T1-weighted images. T2-weighted images revealed a lesion with high signal intensity. Postcontrast magnetic resonance imaging scans revealed peripheral enhancement of the lesion. The multimodality imaging findings of ischiogluteal bursitis have not been described previously. Ischiogluteal bursitis should be considered in the differential diagnosis of a buttock mass.

Aged↗
PubMed2003

Fibrotic idiopathic interstitial pneumonia: high-resolution computed tomography considerations.

The fibrotic idiopathic interstitial pneumonias comprise usual interstitial pneumonia (UIP) and nonspecific interstitial pneumonia (NSIP). The characteristic high-resolution computed tomography findings of UIP are reticular abnormality and honeycombing with basal and peripheral predominance. Honeycombing is the strongest predictor of UIP. The extent of fibrosis on computed tomography (CT) is an important prognostic indicator in idiopathic pulmonary fibrosis (IPF). When ground-glass attenuation is seen in IPF it commonly progresses to fibrosis and honeycombing. Imaging may help to detect complications of IPF, including accelerated progression, lung cancer, and secondary infection. Our understanding of the clinical and radiological features of NSIP is still evolving. The CT finding of extensive ground-glass abnormality and some reticular abnormality, with basal and peripheral predominance, is strongly suggestive of NSIP. However, the CT appearances of NSIP overlap with those of UIP, organizing pneumonia (OP), and desquamative interstitial pneumonia (DIP), and biopsy may be necessary to sort this out. Other idiopathic pneumonias that may be associated with CT evidence of lung fibrosis include DIP, OP, acute interstitial pneumonia, and lymphoid interstitial pneumonia.

Journal Article↗