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At least 163 records · Page 9Linked to original sources

New methods for quantifying diplopia.

PURPOSE: To develop new methods for quantifying diplopia and test their validity, test-retest reliability, and responsiveness to treatment. DESIGN: Prospective case series. PARTICIPANTS: Adult patients with diplopia in 2 tertiary referral practices. Diagnosis included cranial nerve palsies, thyroid eye disease, supranuclear palsies, and ocular myasthenia gravis. METHODS: The new diplopia questionnaire and cervical range of motion (CROM) diplopia examination were tested in a 15-patient validity study against the standard diplopia field performed on the Goldmann perimeter (each scored 0 [no diplopia] to 100 [constant diplopia in all fields]). The test-retest reliability of the CROM diplopia examination was determined in 27 patients. The responsiveness to treatment of the diplopia questionnaire and the CROM examination was tested in 15 patients who underwent strabismus surgery or received systemic prednisone for ocular myasthenia gravis. MAIN OUTCOME MEASURES: Validity was evaluated by the intraclass correlation coefficient (ICC) compared with the standard Goldmann diplopia field. Test-rest reliability was evaluated by the ICC. Responsiveness to treatment was evaluated by comparing pretreatment and posttreatment scores. RESULTS: There was excellent agreement between the diplopia questionnaire score and Goldmann diplopia field score (ICC, 0.90) and between the CROM diplopia examination score and Goldmann diplopia field score (ICC, 0.88). Intertester reliability of the CROM diplopia examination score was excellent (ICC, 0.87; 95% confidence interval, 0.74-0.94). Postintervention scores were significantly lower than baseline (P = 0.0003 for CROM and P = 0.0001 for the questionnaire), with a median postintervention improvement of 48 for the CROM diplopia score (quartiles 12-68) and 36 for the diplopia questionnaire (quartiles 20-52). CONCLUSIONS: Our new diplopia questionnaire and new CROM diplopia examination are valid, reliable, and responsive measures of diplopia severity. The tests are easy to administer and require less expensive and less cumbersome equipment than previously available.

Adult↗

A new method for the determination of ethanol in the blood and urine by pulse heating.

We have established a new method for the determination of ethanol and other gaseous substances in even minute amounts of biological material by utilizing a Curie-point pyrolyzer (Model JHP 3, Japan Analytical Industry) connected to GC or GC-MS. No pretreatment of the biological material is needed and the procedure is based on the principle that volatile or gaseous substances can be evaporated from biological materials by pulse heating and introduced for analysis directly to a GC or GC-MS. The blood from rats that had been administered ethanol-d6 orally, as well as blood and urine collected from healthy volunteers that had ingested alcoholic drinks and blood and tissue specimens taken from autopsied cadavers were examined for ethanol concentrations by both this new method and by the usual head space-GC method. To test this new method, one microliter of the blood or urine was injected into a tubularly folded ferromagnetic alloy (Pyrofoil) and heated pulsatively five times at 160 degrees C (pulse heating). The vapor that evaporated from the sample then was directly introduced to the GC or GC-MS, and the time required to complete the analysis took approximately 5 min. In parallel, for comparison purposes, portions of the same samples (0.2-0.5 g) were examined by means of the head space method as well. The measured values of ethanol-d6 and ethanol in the rat blood and in the human whole blood, blood plasma, and urine that were obtained by this pulse heating procedure correlated almost perfectly with those obtained by head space method. These results show the accuracy and reproducibility of this new method.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

Immunogold-silver staining: new method of immunostaining with enhanced sensitivity.

A new method for demonstrating antigens in paraffin sections of formol sublimate-fixed tissue is described that utilizes an "indirect" immunohistological technique employing immunoglobulin adsorbed to colloidal gold as the secondary antiserum. The gold particles introduced to antigenic sites are revealed by a silver precipitation reaction. This technique, the immunogold-silver staining method, is of much enhanced sensitivity (up to 200-fold) as compared with standard immunoperoxidase and immunogold staining methods. The results have been confirmed in a study of immunoglobulins in reactive human tonsil. The use of this new method for double immunolabeling is also described.

Animals↗

A new method of perfusion fixation for the rabbit femur.

We report a new method of perfusion fixation for the proximal one-third of the femur of the Japanese white rabbit. Fluids to flush the blood and fix the marrow were injected into the abdominal aorta and drained from the stump of the femur. The oozing of the fluids from the stumps guaranteed complete flushing and fixation. The new method facilitated fixation and decreased the volume of necessary fluids. Scanning electron microscopy (SEM) images of bone marrow fixed using the new method and using the conventional method did not differ. Large fat globules were not observed in the SEM specimens produced using either the new or the conventional method.

Animals↗

The Littler line method and the area under a Gaussian curve: a new method of assessing digital range of motion.

A new method of measuring digital range of motion (the Littler line method) is presented. When a Gaussian curve is centered over the Littler line and the appropriate area under the curve is computed, this area can provide a measure of the functional range of motion regained by an injured digit. Seventeen children (24 digits) with flexor tendon injuries were evaluated at an average follow-up period of 58 months (range, 12-121 months). The Littler line/Gaussian curve method was found to be more reproducible than total active motion, particularly in zone I and II injuries. This method can serve as a more meaningful functional assessment tool than a linear measurement such as total active motion, because it emphasizes digital motion in the mid-ranges of digital motion. (J Hand Surg 2001;26A:23-30.

Adolescent↗

A new method for measurement of respiratory resistance.

A new method for measuring the resistance of the total respiratory system is presented. The method uses a device comprising a solenoid valve, a multiperforated plate, and a pneumotachograph. The multiperforated plate serves as a constant resistor (Rk) that is used to partially occlude the airway opening, thus rapidly and briefly reducing airflow during natural expiration. If it is assumed that the driving pressure remains constant during the very short period the airway is partially occluded, the respiratory flow immediately preceding the addition of Rk (V) and the flow reduction during partial occlusion (delta V) allow calculation of the resistance of the total respiratory system. The resistance of 14 normal subjects and 18 patients with chronic obstructive pulmonary disease (COPD) was measured with this new method as well as with the body plethysmographic method: 90% of the interrupter values fell within +/- 0.6 cmH2O . l-1.s of the plethysmographic values, and all fell within +/- 0.8 cmH2O . l-1.s.

Airway Resistance↗

A new method for preparing electron microscopic specimens of Helicobacter pylori.

Abstract A new method for preparing electron microscopic specimens of Helicobacter pylori was developed and used to examine the ultrastructure of this bacterium. We have also investigated the morphological changes in the bacterium when exposed to amoxicillin using our new method. Bacterial specimens for electron microscopy are usually prepared by collecting the bacteria by centrifugation during the fixation and dehydration processes. In our new method the bacteria are filtered through and adsorbed onto a filter before fixation, and the entire filter containing the adhered bacteria is fixed and dehydrated. Using this method we were able to obtain electron photomicrographs in which the external appearances or internal structures of the bacteria were well conserved. The advantages of this method are that it uses only a small amount of bacterial suspension, shortens the time required for the dehydration procedure, and keeps the artifacts to the minimum. Amoxicillin treatment resulted in coccoid form with blebs in the bacterial surface and the appearance of vacuoles, granules, and an area of low electron density in the cytoplasm at one and four minimum inhibitory concentrations. These changes were consistent with results previously reported in the literature.

Journal Article↗

A new method of autotomography with cerebral angiography (angioautotomography).

A new method of autotomography for cerebral angiography, accomplished by means of a simple and handy device, has made it possible to take arbitrary tomographic planes of angiograms which result in clear cut views of the tomogram. The principle of the device is described, the method of use explained and representative films, produced by this new method, are demonstrated.

Brain Neoplasms↗

Lateral pelvic displacement during walking: retest reliability of a new method of measurement.

This study examined the retest reliability of a new method of measuring the amplitude and symmetry of lateral pelvic displacement (LPD) during walking. Previous methods of quantifying LPD did not consider variations in walking direction or enable quantification of side-to-side symmetry of LPD. Therefore, the new method was developed to measure the amplitude and symmetry of LPD relative to the base of support provided by the feet. Three-dimensional motion analysis was used to collect the coordinates of markers placed on the sacrum and heels of 20 unimpaired adults. Subjects performed three 10 m walking trials at their preferred speed. Between trial 1 and 2 the markers were removed and then reattached. Between trial 2 and 3 the markers remained attached. Retest reliability was high for consecutive measurements of amplitude of LPD (ICC (2,1)=0.91), and marker reattachment did not affect the degree of reliability (ICC (2,1)=0.94). The reliability was also high for consecutive measurements of symmetry of LPD (ICC (2,1)=0.80). Marker reattachment did however reduce the reliability of symmetry measures (ICC (2,1)=0.54). This study provides data on the retest reliability of a new method of measuring LPD in unimpaired subjects against which the performance of patients can be compared. Copyright 1998 Elsevier Science B.V. All rights reserved

Journal Article↗

A new method of margin evaluation in breast conservation surgery using an adjustable mould during fixation.

AIMS: We have developed a new method of breast resection margin assessment in quadrantectomy using an adjustable mould to prevent the three-dimensional specimen from distorting during fixation. METHODS AND RESULTS: The new method has been applied to 10 consecutive quadrantectomies (six invasive duct carcinomas, four duct carcinoma in situ with or without microinvasion). The precise configuration of the fixed specimen enabled pathologists to examine the side slices, the 5 mm thick slices cut parallel to the flat lateral margins of the specimen, permitting the separation of margin evaluation from tumour characterization. Eight cases with negative margins by our method would also be negative by assessment of inked margins since the margin widths were estimated to be from 5 to 30 mm (average 16.3 mm); two cases with positive margins would also be positive by inked margins. CONCLUSIONS: Our new method was as reliable as the inked margins employing sequential slicing of the entire tissue, although it reduced the number of blocks by more than half in invasive carcinomas. A further advantage of this method is that the accuracy in margin evaluation is not influenced by the extent of tumour sampling. In addition, our system can pinpoint the positive margins facilitating re-excision to obtain tumour-free margins.

Adult↗

A new method for the simultaneous analysis of growth and death of immunophenotypically defined cells in culture.

BACKGROUND: Internal standards have been used in flow cytometry methods to enumerate lymphoid subsets and hemopoietic progenitor cells ex vivo. However, the currently available methods cannot be readily applied to the analysis of cultured cells because of the frequent occurrence of cell death during in vitro assays. METHODS: This paper reports a new method for the enumeration of both viable and nonviable cells in culture. Cells were counted with the aid of an internal reference standard of microbeads, and live versus dead cell discrimination was performed using 7-amino-actinomycin D which allows the double staining of surface antigens. RESULTS: The method is more precise, accurate and sensitive than either conventional light microscopy-based or automated cell counting. Additionally, it may be used to accurately measure the number of apoptotic cells in a culture. RESULTS: Through the enumeration of surviving cells it is demonstrated that, when applied to the study of mitogen-activated T lymphocytes, current flow cytometry techniques (which do not use internal standards) for the study of the viability and apoptosis overestimate the fraction of viable cells and underestimate both the fraction of dead and apoptotic cells. CONCLUSIONS: The new method overcomes these limitations and is of use in the in vitro study of cell growth and apoptosis.

Apoptosis↗

New method to obtain the midplane dose using portal in vivo dosimetry.

PURPOSE: The aim of this study was to develop a method to derive the midplane dose [i.e., the two-dimensional (2D) dose distribution in the middle of a patient irradiated with high-energy photon beams] from transmission dose data measured with an electronic portal imaging device (EPID). A prerequisite for this method was that it could be used without additional patient information (i.e., independent of a treatment-planning system). Second, we compared the new method with several existing (conventional) methods that derive the midline dose from entrance and exit dose measurements. METHODS AND MATERIALS: The proposed method first calculates the 2D contribution of the primary and scattered dose component at the exit side of the patient or phantom from the measured transmission dose. Then, a correction is applied for the difference in contribution for both dose components between exit side and midplane, yielding the midplane dose. To test the method, we performed EPID transmission dose measurements and entrance, midplane, and exit dose measurements using an ionization chamber in homogeneous and symmetrical inhomogeneous phantoms. The various methods to derive the midplane dose were also tested for asymmetrical inhomogeneous phantoms applying two opposing fields. A number of combinations of inhomogeneities (air, cork, and aluminum), phantom thicknesses, field sizes, and a few irregularly shaped fields were investigated, while each experiment was performed in 4-, 8-, and 18-MV open and wedged beams. RESULTS: Our new method can be used to assess the midplane dose for most clinical situations within 2% relative to ionization chamber measurements. Similar results were found with other methods. In the presence of large asymmetrical inhomogeneities (e.g., lungs), discrepancies of about 8% have been found (for small field sizes) using our transmission dose method, owing to the absence of lateral electron equilibrium. Applying the other methods, differences between predicted and measured midplane doses were even larger, up to 10%. For large field sizes, the agreement between measured and predicted midplane dose was within 3% using our transmission dose method. CONCLUSIONS: Using our new method, midplane doses were estimated with a similar or higher accuracy compared with existing conventional methods for in vivo dosimetry. The advantage of our new method is that the midplane dose can be determined in the entire (2D) field. With our method, portal in vivo dosimetry is an accurate alternative for conventional in vivo dosimetry.

Humans↗

Perception without attention: results of a new method.

Having found by the use of a new method for examining perception without attention that grouping and texture segregation do not seem to occur (see Mack, Tang, Tuma, Kahn, & Rock (1992) Cognitive Psychology, 24, we go on to ask what is perceived without attention using this new method. Our subjects receive only one inattention trial in a sequence of trials involving a visual distraction task. In addition to the distraction task in the inattention trial, subjects received a stimulus of which they had no prior knowledge or expectation and were questioned or tested directly afterward for their perception of that stimulus. Two subsequent trials containing test stimuli serve as within-subject controls. The results of a series of experiments indicate that the presence of one or more stimulus objects and their locations are preattentively perceived, as is their color, but shape is not. Because individual items are detected without attention, we conclude that perceptual organization is initially based on a principle in which connected regions of uniform stimulation are inferred to be discrete units (the principle of uniform connectedness). One striking, unexpected finding is that without attention many subjects have no awareness at all of the stimulus object, an effect we call inattentional blindness.

Attention↗

A new method for laryngeal electromyography.

A new method of surface electromyography (EMG) is presented, for sampling the posterior crico-arytenoid, interarytenoid and crico-pharyngeal sphincter. The results obtained in normal volunteers are discussed and the indications for laryngeal electromyography (LEMG) outlined. It has the advantage of being non-invasive and safe, and can be done as an out-patient procedure with minimal discomfort to the patient, and unassociated complications. This has provided a new and fascinating field of investigation in neuromuscular disorders of the larynx. The same principles of surface EMG may also be applied to the muscles of the tongue, palate, pharynx . . . and surface EMG in the upper respiratory tract may become a valuable method of clinical investigation.

Child↗

New method to study bacterial adhesion to meat.

A new method was developed for the study of bacterial adhesion to meat surfaces. Thin slices of meat (40 microns thick) were inserted into a specially designed observation chamber. The meat slices were then exposed to a bacterial suspension (ca. 10(6) CFU.ml-1) to initiate adhesion (20 min of contact time) and subsequently rinsed to eliminate nonadherent bacteria. Because of the special chamber design, the disruptive force exerted on the bacteria during rinsing (shear stress) was uniform over the whole surface of the meat slices, was constant, and could be varied from 0 to 0.08 N.m-2. After being rinsed, the meat slices were stained with basic fuschin and observed under light microscopy to determine the number and distribution of adherent bacteria. This new method was used to study the adhesion of Acinetobacter strain LD2, a Lactobacillus sp., and Pseudomonas fluorescens to slices of beef fat and tendon. At 25 degrees C, most (greater than or equal to 99.9%) of the cells of the Lactobacillus sp. deposited on the meat were washed off the surface during rinsing (0.05 N.m-2), whereas a large number (ca. 10(5) CFU.cm-2) of Acinetobacter strain LD2 and P. fluorescens cells remained adherent. The extent of adhesion was similar on fat and tendon, and adherent bacteria were distributed evenly over the whole surface of the slices. This preliminary study indicates that the combined use of thin slices of meat and of the observation chamber provides us with the means to more accurately study bacterial adhesion to meat surfaces.

Acinetobacter↗

New method for obtaining conjugated vaccines.

We describe a new method to obtain conjugates against Neisseria meningitidis serogroups A, B, C, Vibrio cholera, and Salmonella typhi and their immunogenicity in Balb/c mice. The saccharides were activated by basic hydrolysis with the generation of amine groups in the saccharidic chain, and these groups were linked to carboxyl groups of tetanus toxoid by via carbodiimida-mediated reaction. The resultant conjugates were administered to mice for the immunogenicity studies. The pirogenicity of LPS was measured by LAL assay. The anti-saccharide IgG, IgG1, and IgG2a antibodies were evaluated. A significant decrease in the pirogenicity of LPS after basic hydrolysis treatment was observed. The conjugates elicited higher titers of anti-polysaccharides or anti-LPS IgG, IgG1, and IgG2a in conjugates than in unconjugated saccharides. The results indicate that we have a new method for obtaining conjugated vaccines and we have demonstrated that after conjugation there was a change in the responses for all saccharides, from thymus-independent to thymus-dependent responses.

Animals↗

A new method for preventing pulse pileup in scintillation detectors.

A new method for preventing pulse pileup in scintillation detectors is proposed. In the new method (G-INT), the energy of an event is calculated from the 'gated integral' of the pulse signal and the period of integration. The period of integration is not fixed but is shortened by the arrival of the succeeding pulse so as to avoid post-pulse pileup. The effect of pre-pulse pileup is corrected by subtracting the remnant energy of the preceding pulses, which is calculated from the gated integral of the preceding pulse. To avoid error due to short pulse intervals, pre- and post-pulse deadtimes are imposed. The method is similar to Wong's method (W-SUM) that depicts the energy by the 'weighted sum' of the current signal and the integrated signal. The performance of G-INT has been studied by Monte Carlo simulation in comparison with W-SUM, the variable sampling-time technique and simple delay-line clipping. It is shown that G-INT provides the smallest degradation in pulse height resolution for a given count rate capability. The difference between G-INT and W-SUM is explained by the difference in the amount of statistical noise involved in the gated integral and in the weighted sum.

Algorithms↗

A new method for assessing the gloss of human skin.

A new method for an objective assessment of the gloss of human skin is presented. The reflectometric measuring set-up complies with DIN 67530. The principle of this new method is based on a contactless determination of the skin's reflection of light from a tungsten filament lamp, recorded at an angle of 60 degrees by a silicon photocell. In a comparative study with 30 test persons it was discovered that the forehead, with 2.70 standardised reflectometer units (RU; SD +/- 0.59 RU), displayed a significantly higher gloss than the lower arm (1.99 RU, SD 0.28 RU, p < 0.0001). In an investigation into the influence of four different cream bases on the skin gloss it could be determined that the value depends on the percentage of grease, the water concentration and the consistency of the respective base. The method presented permits a fast, contactless, randomly repeatable objective assessment of skin gloss. Since the acceptance of cosmetics and pharmaceutical products depends not least on their skin gloss effect, this method can provide valuable information when estimating the success of old and new products.

Adult↗