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Significance: The effects of varying the indocyanine green injection dose, injection rate, physiologic dispersion of dye, and intravenous tubing volume propagate into the shape and magnitude of the arterial input function (AIF) during intraoperative fluorescence perfusion assessment, thereby altering the observed kinetics of the fluorescence images in vivo. Aim: Numerical simulations are used to demonstrate the effect of AIF on metrics derived from tissue concentration curves such as peak fluorescence, time-to-peak (TTP), and egress slope. Approach: Forward models of tissue concentration were produced by convolving simulated AIFs with the adiabatic approximation to the tissue homogeneity model using input parameters representing six different tissue examples (normal brain, glioma, normal skin, ischemic skin, normal bone, and osteonecrosis). Results: The results show that AIF perturbations result in variations in estimates of total intensity of up to 80% and TTP error of up to 200%, with the errors more dominant in brain, less in skin, and less in bone. Interestingly, error in ingress slope was as high as 60% across all tissue types. These are key observable parameters used in fluorescence imaging either implicitly by viewing the image or explicitly through intensity fitting algorithms. Correcting by deconvolving the image with a measured subject-specific AIF provides an intuitive means of visualizing the data while also removing the source of variance and allowing intra- and intersubject comparisons. Conclusions: These results suggest that intraoperative fluorescence perfusion assessment should be corrected by patient-specific AIFs measured by pulse dye densitometry.

A method is described for the preparation of linearising cam. It is based upon the mathematical treatment of the response obtained from an initial scan using the stepwedge prepared from human serum protein on rules, siliconised paper. The form of the equation connecting protein concentration on the paper strip to the reflected light complied with the requirements of a rectangular hyperbola.

Bisalbuminaemia in two members of a Kashmiri family is reported. This, the first Asian variant, is described in terms of its electrophoretic mobilities and dye-binding properties.

A method for lipoprotein electrophoresis on cellulose acetate is described. Features which distinguish this method are: (1) It affords complete resolution of chylomicrons, β-lipoproteins, pre-β-lipoproteins, and α-lipoproteins into distinct bands and allows the relative magnitude of each to be estimated by transmission microden-sitometry. (2) Lipoproteins can be eluted quantitatively from separated bands for analyses. (3) Intact chylomicrons can be recovered by ultrasonic treatment. (4) The procedure is rapid, reproducible, and does not require addition of albumin to the buffer.

We describe here the profiles of antigens of Dirofilaria immitis that are immunogenic in dogs. Purebred beagle dogs were inoculated with a standard number of the infective third-stage larvae of the heartworm. Microfilaremia and anti-heartworm antibody levels were monitored by the Knott's test and by ELISA, respectively. Antibody-binding polypeptides were detected by immunoperoxidase staining of protein blots of detergent extracts of adult parasites from SDS-PAGE gels. Densitometric scans of these blots revealed considerable variation in the profiles of dirofilarial antigens detected by the sera obtained at different stages of the infection. Sera obtained during the prepatent phase, i.e., 3 mo post-infection (titer 1:2000), detected antigens of Mr 75, 80, 100, 130, and 200 kilodaltons. In addition to these antigens, sera obtained at the onset of microfilaremia, 6 mo post-infection (titer 1:30,000), detected antigens of Mr 15, 16, 18, 34, and 38 kilodaltons. Protein blots stained with sera from dogs, which subsequently cleared the microfilaremia and in which the infection became occult, showed that most of the antibody reactivities were directed at antigens of Mr 15, 21, and 38 kilodaltons. The variations in the species of molecules detected in sera obtained during the course of an infection seem to reflect fluctuations in the levels of specific antibodies directed at the individual heartworm antigens. We discuss the apparent role that the metamorphic differentiation of the parasite may play in determining the levels of reactivities of these antibodies at specific stages of the infection.

Scanning laser densitometry was performed on immuno- and dot blots developed on nitrocellulose by treatment of the nitrocellulose with xylene. This method permits the development of simple methods for recording results of immunoblots and of producing semi-quantitative assays from dot blots.

The Ames MPS paper spot test and the cetylpyridinium chloride (CPC)-citrate turbidity test were used to detect urinary glycosaminoglycans (GAGs) as screening tests for the diagnosis of mucopolysaccharidoses (MPSs). The simplicity and reliability of these two methods were evaluated. The MPS paper spot test correlated more closely with the carbazole test than did the CPC-citrate turbidity test. The monodimensional electrophoresis of Cappelletti et al was also used to screen the subtypes of MPSs using differences in electrophoretic patterns. MPS VII cannot be distinguished from normal by its electrophoretic pattern, but can be detected by the MPS paper spot test. Therefore, the MPS paper spot test combined with monodimensional electrophoresis can detect these subtypes of MPSs (MPS I-II, III, IV, VI, VII). Since only 20 ml of random urine is needed and the result can be obtained with complete reliability in only 7 hours, this screening test appears to be useful for the early diagnosis of MPSs.

A dot-immunobinding assay on nitrocellulose membranes has been developed for the quantification of human IgG subclasses using subclass-specific monoclonal antibodies. The advantages of this technique can be summarized as follows: (1) possibility of rapid semi-quantitative evaluation and/or precise quantitation from the same dot-pattern; (2) simple procedure with very good reproducibility; (3) sensitivity for nanogram concentrations of individual subclasses, therefore applicable not only to serum but also to other body fluids with a low content of IgG; (4) very small amounts of test material needed; (5) very good correlation of results with other techniques (ELISA, radial immunodiffusion) but without some of the inherent problems of the latter methods.

A test program was conducted to check the sensitivity and the accuracy of the hydrogen sulfide (H2S) paper tape sampler as it has been used since its introduction several years ago. Test data from this sampler were compared with those from a sampler modified by researchers from the San Francisco Bay Area Air Pollution Control District. A Mylar bag was used as a container into which laboratory air and a measured quantity of reagent-quality H2S were placed to produce a sample of known concentration. A Research Appliance Company standard G2SE sampler with a recorder was used to draw the sample from the bag and read the tape. The data show that the modifications made by the Bay Area Pollution Control District increased the sensitivity over the 0- to 60-ppb range; however, the shape of the modified curve remained the same as that of the original curve. The data also showed that the percentage accuracy remained approximately the same on both the modified and the original curves, the magnitude of the plus or min...

We report a simple solution to the problem of quantitative densitometry of stained nitrocellulose paper. By immersing the paper in a household lubricating oil of matching refractive index, the light-scattering properties of the paper are largely eliminated, allowing precise transmission densitometry in any flat bed densitometer. The method was evaluated on immunochemically stained Western blots of the proteinases cathepsins B and L. An approximately linear relationship was found between the integrated absorbance of the stained zone and the logarithm of the amount of protease applied to the polyacrylamide gel over the range of 150 to 350 ng of cathepsin B and 50 to 250 ng of cathepsin L.

A part of the dye-protein complex formed in paper electropherograms of blood sera cannot be eluted from sections of the electropherograms by heating the sections with a N hydrochloric acid at 100°C. However, the noneluted part of the dye-protein complex may be calculated by assuming that it is adsorbed by the paper and therefore by applying the Langmuir isotherm equation.

1. 1. Differences in muscle proteins of the species and subspecies of the genus Xiphophorous are discernable by means of paper electrophoresis. 2. 2. The lower limit of differentiation was found at the subspecies level, as the microevolutionary divergences of isolated populations of the species maculatus could not be detected with this method. 3. 3. The electrophoretic data parallel the independently established taxonomic division of the genus Xiphophorus into three species groups. Thus, there are two extreme pattern groupings and one intermediate for both species groups and muscle proteins.

Der Verfasser beschreibt eine Apparatur zur objektiven Auswertung der Papierelektrophoretogramme. Er benutzt ein Coleman-Spektrophotometer und einen besonders entwickelten Adapter.

It has been proposed that particles within tubules and vesicles of the Golgi apparatus of liver cells are precursors of very low density lipoproteins in blood plasma. To characterize these particles we isolated a cell fraction rich in Golgi apparatus and associated particles from rat liver in quantities sufficient for analysis. Particles freed from the membranes of the Golgi apparatus and floated at d = 1.006 were studied by chemical analysis, immunodiffusion, and paper electrophoresis. The lipid composition of the Golgi particles was similar to that of very low density lipoproteins from the same rats. The protein content was about 10% of dry weight for both the Golgi particles and plasma very low density lipoproteins. The Golgi particles formed lines of identity with plasma very low density lipoproteins during immunodiffusion against antiserum to plasma very low density lipoproteins. On paper electrophoresis, however, many Golgi particles remained near the origin, with only a few migrating to the pre-beta position. It was concluded that the lipoproteins in the Golgi apparatus are the precursors of plasma very low density lipoproteins.