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At least 73 records · Page 4Linked to original sources

Colour-black pattern reversal visual evoked potentials (colour-black-PVEPs): neurobiological aspects and clinical applicability of a new method.

The new method of Colour-Black-PVEPs was applied to 67 healthy subjects with normal colour vision who were subdivided into age groups (= AG) I (N = 40: 18-30 years) and AG II (N = 27: 31-60 years): 1. For the N80-, P100- latencies and the N80P100-amplitudes of all Colour-Black-PVEPs we obtained age-, sex- and eye-matched normative data. 2. The female subjects of AG I showed shorter (p less than or equal to 0.05 resp. 0.002) P100-latencies and higher (p less than or equal to 0.02 resp. 0.0001) N80P100-amplitudes in the Colour-Black-PVEPs than the male subjects. In AG II, however, the Colour-Black-PVEPs did not show any more sex-differences for the P100-latencies, whereas the N80P100-amplitudes remained significantly higher for the females. 3. In the Colour-Black-PVEPs the N80- and P100-latencies did not reveal age-dependent changes. The N80P100-amplitudes, however, decreased with increasing age, but this was significant for the females only. 4. The head sizes, although decreasing with age, were in both age groups significant smaller for the females only. 4. The head sizes, although decreasing with age, were in both age groups significant smaller for the females. Therefore, head size alone could not fully explain the sex-differences in the Colour-Black-PVEPs and their age-dependent changes. 5. In both age groups, the N80--and P100-latencies increased significantly for both sexes from the Green-Black- and Red-Black-PVEPs to the Blue-Black-PVEPs. The N80P100-amplitudes decreased in the same sequence. This method may become a valuable tool in the investigation of neurophysiological and ophthalmoneurological aspects of human colour vision.

Adolescent↗

[Localization diagnosis of epithelial-body tumors through selective determination of parathyroid hormone. Surgical sequelae of a new method].

A new method for the localisation of abnormal parathyroid tissue is reported. This is carried out by selective venous blood sampling from the thyroid veins and the large veins of the neck. Parathyroid hormone levels are measured by radioimmunoassay. The peak hormone level indicates the site of the tumor suspected. Parathyroid venous blood was taken in 15 patients with primary hyperparathyroidism. In 12 patients localisation of the parathyroid tumor was achieved pre-operatively. The procedure is especially valuable in patients with previous unsuccessful parathyroid surgery. There are no complications or contraindications to the method.

Adenoma↗

[The three-dimensional structure of the tunica intima and tunica media of the human fetal aorta studied by a new method].

A new method is developed for revealing the latent surfaces in the structure of organs by scanning electronic microscopy. The method is based on the treatment of specimens with potassium ethoxide until cells start to appear in the dissociating solution. Using this method, thoracic aorta of nine human fetuses at the stage of 20-28 weeks was studied. Subendothelial intima and media of human fetal aorta contain smooth muscle cells differing by their arrangement, shape and surface microrelief. The intima cells are arranged in a mosaic pattern formed of single cells or cell clusters. By means of cell processes they are connected with each other, as well as with endothelial and smooth muscle cells of the media. Smooth muscle cells in the inner part of the media also have processes and form an open network. Part of the cells penetrate the intima through pores of the inner elastic membrane. In the deeper layers of the media, laterally adjoining spindle-shaped smooth muscle cells are found. It is suggested that the observed cell polymorphism is due mostly to penetration of the media smooth muscle cells into subendothelium and modification of their shape under the effect of the microenvironment.

Aorta, Thoracic↗

[Cholecystectomy using median minilaparotomy. A new method].

A new methodization is proposed to perform cholecystectomy through a minor laparotomy (3-6 cm) in midline (in the middle third of the linea alba). Twenty-one patients were submitted to cholecystectomy by gallstones including acute cholecystitis. No postoperative complications occurred and the discharge from hospital was in the first and second day.

Adult↗

Increasing flap survival: a new method.

A new method of continuous irrigation beneath a flap with special irrigation was designed to attempt to improve flap survival in 42 animals. In each animal experimental and control flaps were symmetrically designed using two flanks or limbs (total number of flaps, 154). The flap length survival in the 77 experimental flaps ranged from 18 to 88% greater than that in the control flaps. Bacterial cultures of the secretions from all flaps suggested that this method has a practical value in preventing and controlling the infections that would result in flap necrosis.

Animals↗

Human trabecular meshwork organ culture. A new method.

A new method has been developed for organ culture of human trabecular meshwork. Human eyebank eyes are sectioned at the equator and lens and vitreous are removed. The anterior segments are placed in a modified culture dish, cornea side up, and then sealed in place. Culture media (Dulbecco's modified Eagle media) are perfused through a cannula built into the bottom of the dish. The sealed system forces media to flow through the trabecular meshwork, Schlemm's canal, and exit through the normal limbal pathways. Intraocular pressure can be maintained at normal (or elevated) levels throughout the culture period. Corneal clarity is maintained. Trabecular cells remain in normal position on trabecular beams and maintain many of their usual morphologic characteristics. Cultures appear to be viable for up to 4 weeks. This technique should allow study of intact human trabecular meshwork in a controlled experimental fashion.

Aged↗

Measurements of precipitin reactions by difference turbidimetry: a new method.

A new method for the measurement of precipitin and flocculation reactions between antibodies and antigens has been developed. The technique, called difference turbidimetry, involves the use of tandem cuvettes providing the opportunity of using separated and unmixed antigen and antibody as blank solutions for spectrophotometric readings in the ultraviolet wavelength range. By use of this technique genuine difference turbidity spectra have been recorded for the reaction between human serum albumin and rabbit-anti-human serum albumin IgG. It was found that difference turbidimetry at low wavelengths (e.g. 280 nm) allows the construction of precipitin curves with a very clearly expressed zoning phenomenon at a sensitivity which in terms of antigen and antibody concentrations is more than twice the sensitivity of conventional procedures. It is of special interest that the zone of equivalence differs when the same reaction between an antigen and its antibody is measured by difference turbidimetry, by absorbance of washed and redissolved precipitate, and by amount of precipitated antigen.

Antigen-Antibody Reactions↗

Radioconglutinin-binding azssay for circulating immune complexes: a new method.

A new method for the detection of circulating immune complexes using radiolabelled conglutinin as a marker for complement-bound complexes precipitated in low concentrations (3.5%) of polyethylene glycol is described. The optimal laboratory conditions for the test have been defined and certain limitations studied. The technique is simple with good reproducibility and high degree of specificity. In a double-blind study of eighty-seven samples of sera from normals, patients with glomerulonephritis, post-renal transplantation, rheumatic diseases, breast tumours, multiple sclerosis and infections the method was compared and correlated to the Clq-binding assay and the Raji cell test. The radioconglutinin-binding assay was most discriminative for cases of glomerulonephritis, renel transplantation, breast carcinoma and multiple sclerosis and least for rheumatoid arthritis.

Antigen-Antibody Complex↗

Discharge frequency of the motor units in human muscles under different stationary isometric tension, investigated by a new method.

A new method has been worked out for selective recording of the impulses of individual MU under high muscular efforts. It is suggested to use the EMG derivatives (the differentiated EMG-DEMG and the double differentiated EMG-DDEMG and possibly the higher derivatives). It was demonstrated that at different stationary isometric tensions the dependence between the discharge frequency and the tension may be linear or non-linear, with a bigger growth at the small efforts and a smaller growth at the big efforts. The inverse non-linearity--sharp rise of the frequency at the high efforts--was not established. Conformation was found for the possibility of distinguishing between two types of MU according to the type of this dependence.

Action Potentials↗

Egg viability in urinary schistosomiasis. II. Simplifying modifications and standardization of new methods.

Two new methods were recently introduced for the determination and quantification of egg viability in Schistosoma haematobium infections by staining eggs filtered from urine on Nytrel filters with mercurochrome and iodine. Both methods showed reasonable agreement with the best currently available method, centrifugation hatching, but it appeared that improved agreement could be obtained by modifications of timing and technique. The present paper describes the standardization of staining times and microscopic counting techniques; the modifications made gave substantially improved agreement with the reference method and achieved the most important objective, not to have zero estimates of viability when the centrifugation method detected hatching.

Animals↗

A new method for optimizing multiplex DNA microsatellite analysis in low quality archival specimens.

BACKGROUND: Testing microsatellite instability seems to be a useful tool for the initial screening of putative non-polyposis colorectal cancer (HNPCC), preceding analysis of germ-line mutations of DNA mismatch repair genes. However, diagnosis of microsatellite instability becomes complicated when highly-damaged DNA from formalin-fixed paraffin-embedded tissue specimens has to be investigated. MATERIALS AND METHODS: A new methodical approach was established based on special multiplex PCR regimes (e.g., on touch-up cycling conditions), allowing both sufficient, as well as specific, amplification of the Bethesda reference panel loci with low quality DNA as template. RESULTS: By applying our new method, microsatellite instability could be analyzed successfully in 75 out of 84 investigated tumors (89%), whereas, by using standard PCR protocols, microsatellite analysis failed in 36% of the investigated cases. CONCLUSION: Our new methodical approach should be recommended for the use of archival material since it allows an efficient and accurate amplification of the Bethesda marker fragments and is less dependent on the DNA quality.

Adaptor Proteins, Signal Transducing↗

[Results of testing a new method of using antibiotics in nutrient media for the isolation of Shigella: the 2-streak method].

A new variant of media with antibiotics for isolation of Shigella, i.e. a method of 2 streaks each containing different antibiotics was tested in analysis of excrements from patients with acute dysentery. It was found that the new method is more effective than the well known method of gradient plates (isolation of Shigella in one series of the experiments amounted to 85.2 and 64.7 per cent respectively, and in the other series of the experiments the respective figures were 95.4 and 89.3 per cent). Its efficiency was lower as compared to the procedure of inoculation onto 2 plates, i.e. onto the media with and without an antibiotic (isolation of Shigella was 67.5 and 77.4 per cent respectively). The new method provided a higher frequency of Shigella isolation as compared to inoculation onto the media without an antibiotic, as well as onto any of the media used with one antibiotic. The method of 2 streaks offers wider possibilities for choosing the antibiotics for adding to the nutrient medium, as well as estimation of the antibioticograms and species structures of Shigella distributed in a concrete area.

Anti-Bacterial Agents↗

Measuring body image. Preliminary report on a new method.

A new, very simple and inexpensive METHOD FOR MEASUREING BODY IMage is described. A number of female patients with different somatic complaints were investigated. A specific patterning of body image related to the localization of somatic complaints is revealed. Anorexic and obese patients have an overall larger body image while the distortions in other conditions mostly go on the elevation in the vertical axis. Different aspects of this way of measuring body image are discussed, but the difference of the patterning is clear. This is a preliminary report on the new method.

Anorexia Nervosa↗

Utilization of short-chain fatty acids by colonic mucosal tissue strips. A new method of assessing colonic mucosal metabolism.

BACKGROUND: Previous metabolic studies of the colonic mucosa have been done using isolated cells or small biopsy specimens. METHODS: A new method for assessing the utilization of short-chain fatty acids in human colonic mucosal tissue strips considerably larger than routine samples was evaluated and compared with the method of isolated colonocytes. Human colonic mucosal strips and isolated human and rat colonocytes were incubated with acetate (C2), butyrate (C4), and hexanoate (C6), and oxidation rates obtained by quantifying the production of CO2. RESULTS: The wet weight of strips was highly correlated with the production of CO2, and intersample coefficient of variance was <10%. The production of CO2 from the oxidation of C2, C4, and C6 was in the order of C2 > C4 > C6 for both strips and isolated human and rat colonocytes. The production of adenosine triphosphate (ATP) in strips and isolated human and rat colonocytes was in the order of C2 < or = C4 < or = C6. The Km value for the oxidation of butyrate to CO2 in strips (1.8 mmol/l) was several times higher than previously reported for isolated human and rat colonocytes (0.1-0.3 mmol/l). CONCLUSIONS: This new method is highly reproducible and able to assess the metabolic activity of the colonic mucosa. The high Km value of butyrate oxidation in mucosal strips seems to reflect the in vivo Km value of colonocytes and shows the importance of a preserved anatomic structure in metabolic studies of the colonic epithelium. The low Km value for isolated colonocytes probably reflects the intracellular ability to oxidize butyrate. We propose that both isolated colonocytes and mucosal strips be used in studies of colonic mucosal metabolism. This method is relevant in disease states of the colon in which a disagreement prevails as to the ability to oxidize butyrate by colonocytes, such as in ulcerative colitis.

Acetates↗

Determination of axial rotation angles of limb segments - a new method.

This paper describes a new method of determining the axial rotation angle of a limb segment during three-dimensional movement. Instead of describing the three-dimensional rotation by a three-step rotation (Euler/Cardan angles), a one-step rotation (instantaneous screw axis), or a non-step rotation (floating axis method), the new method uses a two-step rotation to describe the three-dimensional rotation of the limb segment: the rotation of the long axis of the limb segment about a specific axis passing through the proximal joint centre and perpendicular to the long axis of the limb segment, and the axial rotation about the long axis. A short review of previous methods followed by a full description of the principle of the new method with detailed derivation of some important equations (Appendices), comparison with Euler/Cardan angles and a simple experimental demonstration are given in this paper. A method of solving the gimbal-lock problem when using this method is also proposed.

Biomechanical Phenomena↗