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Regional deposition of coarse particles and ventilation distribution in healthy subjects and patients with cystic fibrosis.

The efficacy of inhaled pharmaceuticals depends, in part, on their site of respiratory deposition. Markedly nonuniform ventilation distribution may occur in persons with obstructive airways diseases and may affect particle deposition. We studied the relationship between regional deposition (RDep) and regional ventilation (RVent) in a group of 12 cystic fibrosis (CF) patients with mild to moderate airway obstruction (63 +/- 8% predicted FEV1) and 11 healthy nonsmoking volunteers (104 +/- 13% predicted FEV1) using planar scintigraphic methods. RDep was assessed from initial deposition and 24-h retention images for monodisperse technetium-99m-labeled iron oxide particles (5-microm MMAD). Regional volumes and RVent were assessed from xenon-133 equilibrium and washout, respectively. Six regions of interest per lung were established by dividing each lung into thirds by height and approximately half by width. The two lower regions of the left lung were not analyzed due to activity in the stomach. Remaining regions were categorized as central (two interior-most regions) and peripheral (eight exterior regions). RDep and RVent were computed for the eight peripheral regions. Tracheobronchial (TB) deposition was estimated for each of the peripheral regions as the difference between initial activity and decay-corrected 24-h retention or parenchymal deposition. RDep was computed as the fraction of material within a region normalized to regional volume. RVent for each region was determined by normalizing the xenon washout rate for that region by the total washout rate for the eight peripheral regions. Significant linear associations were found between RDep and RVent in both the healthy subjects and CF patients. In healthy subjects, RDep in the TB airways was positively associated with RVent (p = 0.03). In CF patients, RDep in the TB airways was negatively associated with RVent (p = 0.04) and RDep in the parenchyma was positively associated with RVent (p < 0.001). The initial pattern of RDep in the lung was not significantly associated with RVent in either group. These data suggest that significant coarse particle deposition may occur in the TB airways of poorly ventilated lung regions in CF patients, whereas, particle deposition in the TB airways of the healthy subjects follows ventilation.

Administration, Inhalation↗

Eye movement analysis: reading and moving target pursuit.

The design and application of an extensive and general software-based system for the study and analysis of eye movements in human subjects is described. The system can find application in a number of specialties in medicine, particularly clinical neurophysiology, as well as in studies of eye movement dynamics, including reading dynamics, in dyslexia. It is designed to run on the PDP 11 family of computers with standard peripherals and operating under the RT 11 executive.

Computers↗

Computed tomography of hepatic fascioliasis.

In seven patients with active fascioliasis of the liver, CT revealed nodular intrahepatic lesions of diminished attenuation, as well as peripheral branching formations. Computed tomography was negative in a single patient with quiescent disease. Computed tomography can be a useful tool for the diagnosis of this disease during the invasive period and also to evaluate response of patients to medical treatment.

Adolescent↗

Computer-assisted cytogenetic analysis of 51 malignant peripheral-nerve-sheath tumors: sporadic vs. neurofibromatosis-type-1-associated malignant schwannomas.

Cytogenetic studies in small groups of patients with malignant peripheral-nerve-sheath tumors (MPNST) revealed complex karyotypes with no consistent changes. A computer-assisted cytogenetic analysis using a cytogenetic database was performed to determine recurrent cytogenetic alterations in 51 MPNSTs (44 from the literature and 7 new cases) and to allow direct cytogenetic comparison between NF-1-associated and sporadic MPNSTs. Significant loss (p < 0.05) was observed in the chromosomal regions 9p2, 11p1, 11q2 and 18p1. Also, loss in 1p3, 9p1, 11q1, 12q2, 17p1, 18q1-q2, 19p1, 22q1, X and Y was detected. Gain of chromosomal material was found in chromosome 7, especially 7q1 (p < 0.05). Most involved breakpoints were: 1p13, 1q21, 7p22, 9p11, 17p11, 17q11, 22q11. Cytogenetic differences between NF-1-associated and sporadic MPNSTs included a relative loss of chromosomal material in NF-1-associated MPNSTs in 1p3, 4p1 and 21p1-q2 and a relative gain in 15p1-q1. Differences in breakpoints between the NF-1 associated and the sporadic MPNST group were observed in 1p21-22 (28% of NF-1 vs. 0% of sporadic MPNSTs), 1p32-34 (17% vs. 0%), 8p11-12 (7% vs. 27%) and 17q10-12 (24% vs. 7%). This approach, in which the cytogenetic results of various reports are combined, shows that losses in 9p2 and gains in 7q1 could be of oncogenetic importance in MPNSTs. Loss of 17q1, on which the NF-1 gene has been located (17q11.2), is not a common cytogenetic finding in NF-1-associated MPNSTs. The observed differences between NF-1-associated and sporadic MPNSTs might reflect different oncogenetic pathways.

Adolescent↗

Cardiovascular calcification in Hispanic Americans (HA) with chronic kidney disease (CKD) due to type 2 diabetes.

BACKGROUND: Cardiovascular calcification (CVC) is common and severe in patients with end-stage renal disease on dialysis. However, the prevalence and severity of CVC is less well documented in patients with chronic kidney disease (CKD) not yet on dialysis. METHODS: Fifty-eight nondialyzed HA with type 2 diabetes and CKD were enrolled. They comprise 29 patients with stages 1 and 2 CKD (early CKD group) and 26 patients with stages 4 and 5 CKD (advanced CKD group). Coronary artery calcification (CAC) was measured by ultrafast spiral computed tomography, while peripheral artery calcification (PAC) was evaluated by plain x-ray of the chest, pelvis, thighs, and lower extremities. RESULTS: The prevalence of CAC and PAC were significantly higher in the advanced CKD group compared to the early CKD group (73% vs. 38%; P < 0.01 and 85% vs. 35%; P < 0.0001, respectively). The median CAC scores were 18-fold greater in the advanced CKD group (138.9 vs. 7.8, respectively). By linear regression analysis, a strong association was found between the level of renal function and ln total volume of CAC. CONCLUSION: Our data indicate that CAC and PAC are common and severe in HA diabetic patients with CKD not previously treated with dialysis, calcium-based phosphate binders, or vitamin D analogues. Lower level of renal function is associated with increased burden of vascular calcification in predialysis patients with CKD.

Adolescent↗

Insulin kinetics after portal and peripheral injection of [125I] insulin: II. Experiments in the intact dog.

Insulin metabolism in man is usually investigated by peripheral injection of the hormone, whereas native insulin undergoes hepatic extraction prior to mixing in the general circulation. To quantify this difference, in 10 dogs [125I] insulin was injected into a peripheral vein, and the initial distribution volume (IDV), the metabolic clearance rate (MCR), and the mean transit time (t) were computed from the plasma disappearance curve of the immunoprecipitable activity. The splenic vein was then cannulated under pentobarbital anesthesia, and the parameters were again computed from the peripheral activity after portal introduction of the tracer. The MCR after portal injection [15.1 +/- (SE) 1.1 ml/min per kg] was greater (P is less than 0.001) than the MCR after peripheral administration (13.4 +/- 0.9 ml/min per kg). Also, IDV was larger (P is less than 0.01) after portal injection (167 +/- 12 vs. 138 +/- 10 ml/kg). Mean transit times did not change significantly. Insulin secretion rate (0.29 +/-0.04 mU/min per kg) and body insulin mass (7.03 +/- 1.5 mU/kg) were also measured. An estimate of hepatic extraction was obtained from the difference between the clearance rate values calculated following portal and peripheral injection. Under our experimental conditions, hepatic retention of insulin was found to be 19.6% (range 9.6-36.2%). The method is recommended for investigations in man.

Animals↗

Microcomputer based analysis of nystagmus eye movement.

An algorithm to assist in the computation of routine peripheral nystagmus slow phase velocity (SPV) has been implemented on an Apple based data acquisition system. Waveforms stored by the computer may be output to a dot matrix printer to complement conventional strip-chart recorder output. An estimate of SPV is available after each caloric session. Analysis modes range from a summarized output for inclusion in the clinical report to a detailed beat by beat report comprising waveforms, markers and tabulated results. Problematic signals, beyond the scope of the automatic analysis, may be inspected interactively using a software controlled cursor.

Algorithms↗

Intrahepatic peripheral cholangiocarcinoma: CT evaluation.

BACKGROUND: The purpose of our study was to evaluate the imaging features and patterns of contrast enhancement in peripheral cholangiocarcinomas with computed tomography (CT) and correlate these features with histologic findings when available. METHODS: We reviewed the CT scans of 24 patients with 25 peripheral cholangiocarcinomas proved by orthotopic liver transplantation (n = 1), liver resection (n = 7), percutaneous needle biopsy (n = 10), and fine needle aspiration biopsy (n = 6). Incremental dynamic nonhelical CT was performed in four cases and helical CT in 21 cases. Portal venous phase images were obtained in all 25 cases. Fourteen patients underwent helical CT during arterial and portal phases. Delayed images were obtained in 20 patients. RESULTS: The size of the tumors ranged from 1.2 to 17 cm. Bile duct dilatation was present in 13 patients (52%), and regional lymph node enlargement was observed in six patients (24%). Retraction of the liver capsule was present in nine patients (36%). In eight patients (32%), satellite nodules were also detected. All tumors were globally hypodense during the portal phase. In 14 patients (70%), delayed images disclosed hyperattenuating tumors. Rimlike contrast enhancement was the most frequent pattern observed in either arterial (57% of patients) or portal (60% of patients) phase imaging. Portal venous encasement was seen in 10 patients (40%). CONCLUSION: In the proper clinical setting, detection of a hypodense hepatic lesion with peripheral enhancement, biliary dilatation, and contrast enhancement on delayed images are highly suggestive of peripheral intrahepatic cholangiocarcinoma.

Adult↗

Typical results of computer-olfactometry.

After pulsed peripheral olfactory impulses it is possible, under suitable testing conditions, for specific sensory potentials to be read from the surface of the skull and, after repetitions, added up (olfactorially evoked cortical potentials). Typically, there developes a so-called twin-potential containing the equivalents of the electrical activites of the nervus trigeminus and the nervus olfactorius in two peaks of the cortex equivalents. In an objective manner, in other words without intentional or vegetative influence by the test person, it is possible by the weakening or lack of one or the other or both part-potentials to obtain information about the functioning of the olfactory sense. Typical examples will be presented.

Computers, Analog↗

A phase II study of DT fusion protein denileukin diftitox in patients with fludarabine-refractory chronic lymphocytic leukemia.

PURPOSE: Patients with relapsed or refractory chronic lymphocytic leukemia (CLL) have a poor prognosis. We tested the safety and efficacy in these patients of a diphtheria fusion protein DAB(389)IL2 (denileukin diftitox) directed against the interleukin 2 receptor that is expressed by CLL cells. EXPERIMENTAL DESIGN: DAB(389)IL2 was administered by 60 min i.v. infusions for 5 days every 21 days at 9 or 18 micro g/kg/day for up to eight cycles. RESULTS: Eighteen patients were treated. The mean age of the patients was 61.8 years. There were 14 males and 4 females. Two had Rai stage I, 6 had Rai stage II, and 10 had Rai stage IV. The mean number of prior treatments was 4.5 (range, 1-11). Responses were evaluated by peripheral CLL counts, computed tomography scans of all nodes and bone marrow biopsies. Twelve patients received greater than or equal to three cycles of DAB(389)IL2 and were evaluable for response. Eleven of 12 patients showed reductions of peripheral CLL cells, with 6 of 11 showing >/==" BORDER="0">95% reductions. Seven of 12 patients showed reductions of node diameters on exam and computed tomography scans, and 2 of 12 showed 60 and 80% shrinkage, respectively. Pre and postbone marrow biopsies showed a reduction in CLL marrow index in 11 patients. Seven of 11 patients had >50% reduction, including >/==" BORDER="0">98% reduction in 3 patients. DAB(389)IL2 produced 2 of 12 (17%) partial remission and 7 of 12 (58%) minimal responses. Progression-free intervals in the responders were 1, 1, 3+, 4, 9, 10, 10+, 14 and 19+ months. Toxicities were mild to moderate and included asymptomatic, transient transaminasemia, fever, asthenia, hypoalbuminemia, nausea, vomiting, myalgias, rash, anorexia, vascular leak syndrome, and elevated creatinine kinase. Antidiphtheria toxin antibody levels were variable and ranged from 0 to 9 micro g/ml (n = 5). CONCLUSIONS: DAB(389)IL2 produced a rapid decrease of leukemic cells in the bone marrow and peripheral blood of most chemotherapy refractory CLL patients. Most patients also tolerated DAB(389)IL2 well, without significant myelosuppression and/or immunosuppression. The prolonged progression-free interval and subjectively observed quality-of-life in responders is intriguing. The results suggest DAB(389)IL2 has biological activity in patients with B-cell CLL. Follow-up studies of combinations or altered schedules or doses to improve the response rate are warranted.

Aged↗

Factors influencing survival after hepatectomy for peripheral cholangiocarcinoma.

BACKGROUND/AIMS: Radical resection for patients with peripheral cholangiocarcinoma is rare. Prognostic factors related to survival with peripheral cholangiocarcinoma after hepatectomy have not yet been reported. MATERIALS AND METHODS: Of 41 hepatectomized patients with peripheral cholangiocarcinoma, a computer analysis of 14 clinicopathological factors on patients survival was performed with univariate and multivariate analysis. RESULTS: Median and mean survival times for patients with peripheral cholangiocarcinoma after hepatectomy were 12.0 and 22.8 months. The 1-, 2-, 3-, 4- and 5-year survival rates were 53.7%, 39.0%, 36.6%, 26.8%, and 26.8% respectively. Univariate analysis of overall survival involving all patients identified 7 factors that were associated with a significantly outcome: mucobilia (p = 0.043), capsular invasion (p = 0.007), tumor spreading type (p = 0.0003), section margin (p = 0.001), histologic type (p = 0.008), macroscopic and microscopic vascular involvement (p = 0.031), and lymphatic invasion (p = 0.004). With multivariate analysis using the COX stepwise proportional hazards model, only mucobilia, tumor spreading type and section margin were significantly related to prognosis. CONCLUSIONS: Intrahepatic bile duct carcinoma patients with mucobilia, intraductal papillomatosis and a tumor-free margin after hepatectomy had a better prognosis.

Bile Duct Neoplasms↗

Role of computed tomography in guiding the management of peripheral bronchopleural fistula.

The present study was designed to elucidate whether demonstration of a peripheral bronchopleural fistula on CT correlated with the need for surgical management. We retrospectively identified 33 patients, 24 males and nine females, mean age 38 years, with clinical diagnosis of peripheral bronchopleural fistula and whose chest CT scans and medical charts were reviewed. Each chart was reviewed to identify the cause of the peripheral bronchopleural fistula and its treatment. Treatment decisions were categorized as surgical or conservative. Each chest CT was evaluated for the cause of peripheral bronchopleural fistula as follows: bulla(e), lung abscess/necrotizing pneumonia, neoplasms, peripheral bronchiectasis, and trauma. The peripheral bronchopleural fistula was classified as visible on CT if a distinct channel between the lung or a peripheral bronchus and the pleura was seen on the lung windows. We found that CT was useful in guiding surgery by identifying and localizing the cause of the peripheral bronchopleural fistula in the 55% (18/33) of patients who required surgery. The peripheral bronchopleural fistula or its probable cause was identified in 91% (30/33) as follows: bulla(e) (n = 12), lung abscess/necrotizing pneumonia (n = 11), peripheral bronchiectasis (n = 5), malignancy (n = 1), and posttraumatic pneumatocele (n = 1). The peripheral bronchopleural fistula was right-sided in 24, left-sided in nine, and was visible on CT in 36% (12/33). Among the patients with bullae, 58% (7/12) required surgery; however, the peripheral bronchopleural fistula was visible on CT in only 8% (1/12). Among the 21 patients without bulla(e), the peripheral bronchopleural fistula was visible on CT in 52% (11/21). When the fistula was visible in this subgroup, 73% (8/11) required surgery compared with 30% (3/10) in whom the fistula was not visible (p = NS; Fisher exact). In conclusion, CT was useful in guiding surgery by identifying and localizing the peripheral bronchopleural fistula or its probable cause. Peripheral bronchopleural fistulas caused by bulla(e) were less likely to be visible on CT (p < 0.05). Excluding patients with bulla(e), our data suggest a trend toward the need for surgical management for patients in whom the peripheral bronchopleural fistula was visible on CT.

Adolescent↗

[Two cases of Terrien's marginal degeneration treated with peripheral full thickness keratectomy, and followed-up by computer-assisted corneal topography].

BACKGROUND: In 1970 Alberth and Süveges published a method, peripheral full thickness keratectomy, for the treatment of Terrien's marginal degeneration of the cornea. They hypothesized that this type of surgery acts by excising the thinned and extended corneal parts and by restoring normal corneal surface and curvature. METHOD: The right eyes of two patients with Terrien's disease were operated with full thickness keratectomy at our Department, and were followed-up by computer-assisted computer topography. RESULTS: The corneal surface became more regular, astigmatism smaller and fully correctable, visual acuity improved, and the results did not change between 1 and 3 years after surgery in either of the two cases. CONCLUSION: Peripheral full thickness keratectomy, in our experience, proved effective in reducing astigmatism, in improving visual acuity, and in stopping the progression of the disease. Corneal topography can be used in the diagnosis of Terrien's disease, as well as in the postoperative follow-up of patients, giving more information than simple keratometry.

Adult↗

Modification and application of the computerized automatic audiometer.

Recently, medical information processing systems applying computers have achieved marked advances in parallel with the development of highly accurate automatic measuring instruments. The authors already in 1974 developed and reported a computerized automatic audiometer containing a micro-computer which stored a program for audiometric procedures. Subsequently the authors have developed a compact, multi-purpose audiometric instrument which executes the standard air-bone conduction audiometry, with the exclusion of masking, automatically with a built-in micro-computer. An outline of the instrument is as follows: 1. The instrument is composed of a memory, a control unit, programs for data processing and measurement, a character display for instructing subjects and an audiogram display. It can be operated manually in the same way as a conventional audiometer. 2. Test errors and any abnormally large differences between the responses of the two ears can be detected automatically, and the tests can then be re-executed manually after finishing the automatic procedure for correction of the data. 3. The instrument is provided with output terminals for connection to an external computer or other peripheral equipment. It is designed to be compact and light weight.

Adult↗

[Computed tomography and nuclear spin tomography in peripheral lymphedema].

The first reported findings on CT and N.M.R. in two cases of idiopathic peripheral lymphoedema are described. These methods have compared with the generally available volume estimations (volume estimation according to Kuhnke, immersion plethysmography) and have been considered in relation to visual and lymphographic examinations.

Adult↗

Peripheral airways obstruction on high-resolution computed tomography in chronic severe asthma.

Long-standing chronic severe asthma may be associated with structural changes of both proximal and distal airways. To assess these changes, high-resolution computed tomography (CT) using an Imatron Ultrafast CT scanner with 3 mm thick sections at 10 min intervals was performed at full inspiration. A limited set of CT sections was also obtained on full expiration. Twenty-four chronic severe asthmatic patients (age, 47.0 +/- 2.4 years; FEV1, 56.5% +/- 4.1% of predicted) were studied. The scans were assessed independently by two radiologists. While concomitant dilatation and thickening of intrapulmonary airways were observed in 12 patients, air trapping as assessed by areas of increased lucency on expiratory scans was noted in 20. The mean expiratory-to-inspiratory cross-sectional area (Exp/Ins) was 75.9% +/- 2.0%, compared with 44.6% +/- 1.0% in historical non-asthmatic subjects. FEV1 (% predicted) correlated with Exp/Ins and with CT features of air trapping (both rs = 0.60; P < 0.001) but not with airway dilatation or thickening. Our data indicate the presence of peripheral airways obstruction in chronic severe asthma, which may be one of the underlying reasons for increased severity of asthma.

Airway Obstruction↗

A computing scheme for determination of retinal contour from peripheral refraction, keratometry and A-scan ultrasonography.

In this paper a method is described in which retinal contour is derived from measurements of peripheral refraction, keratometry and A-scan ultrasonography. Theoretical aspects are discussed first, followed by a closer examination of the computing scheme and its evaluation. Evaluation involved investigation of inherent errors arising from the computing scheme's methods of compensating for unmeasured human ocular complexities such as crystalline lens asphericity and gradient index optical structure, finite aperture pupils, ocular surface misalignment and toricity. It is found that computed retinal contours are little affected by these inherent errors.

Algorithms↗