Multivariable Logistic Regression Model: A Novel Mathematical Model that Predicts Visual Field Sensitivity from Macular Ganglion Cell Complex Thickness in Glaucoma

Purpose

To design a mathematical model that can predict the relationship between the ganglion cell complex (GCC) thickness and visual field sensitivity (VFS) in glaucoma patients.

Design

Retrospective cross-sectional case series.

Method

Within 3 months from VFS measurements by the Humphrey field analyzer 10-2 program, 83 eyes underwent macular GCC thickness measurements by spectral-domain optical coherence tomography (SD-OCT). Data were used to construct a multiple logistic model that depicted the relationship between the explanatory variables (GCC thickness, age, sex, and spherical equivalent of refractive errors) determined by a regression analysis and the mean VFS corresponding to the SD-OCT scanned area. Analyses were performed in half or 8 segmented local areas as well as in whole scanned areas. A simple logistic model that included GCC thickness as the single explanatory variable was also constructed. The ability of the logistic models to depict the real GCC thickness/VFS in SAP distribution was analyzed by the χ² test of goodness-of-fit. The significance of the model effect was analyzed by analysis of variance (ANOVA).

Results

Scatter plots between the GCC thickness and the mean VFS showed sigmoid curves. The χ² test of goodness-of-fit revealed that the multiple logistic models showed a good fit for the real GCC thickness/VFS distribution in all areas except the nasal-inferior-outer area. ANOVA revealed that all of the multiple logistic models significantly predicted the VFS based on the explanatory variables. Although simple logistic models also exhibited significant VFS predictability based on the GCC thickness, the model effect was less than that observed for the multiple logistic models.

Conclusions

The currently proposed logistic models are useful methods for depicting relationships between the explanatory variables, including the GCC thickness, and the mean VFS in glaucoma patients.     

A Long-Term Cultivation of an Anaerobic Methane-Oxidizing Microbial Community from Deep-Sea Methane-Seep Sediment Using a Continuous-Flow Bioreactor

Anaerobic oxidation of methane (AOM) in marine sediments is an important global methane sink, but the physiological characteristics of AOM-associated microorganisms remain poorly understood. Here we report the cultivation of an AOM microbial community from deep-sea methane-seep sediment using a continuous-flow bioreactor with polyurethane sponges, called the down-flow hanging sponge (DHS) bioreactor. We anaerobically incubated deep-sea methane-seep sediment collected from the Nankai Trough, Japan, for 2,013 days in the bioreactor at 10°C. Following incubation, an active AOM activity was confirmed by a tracer experiment using ¹³C-labeled methane. Phylogenetic analyses demonstrated that phylogenetically diverse Archaea and Bacteria grew in the bioreactor. After 2,013 days of incubation, the predominant archaeal components were anaerobic methanotroph (ANME)-2a, Deep-Sea Archaeal Group, and Marine Benthic Group-D, and Gammaproteobacteria was the dominant bacterial lineage. Fluorescence in situ hybridization analysis showed that ANME-1 and -2a, and most ANME-2c cells occurred without close physical interaction with potential bacterial partners. Our data demonstrate that the DHS bioreactor system is a useful system for cultivating fastidious methane-seep-associated sedimentary microorganisms.     

Alignment and merging of electron microscope images of frozen hydrated crystals of the T4 DNA helix destabilizing protein gp32*I.

Low dose cryoelectron microscopy has been used to record images and electron diffraction patterns of frozen hydrated crystals of the single-stranded DNA binding protein gp32*I. Fourier transforms from 13 image areas, corresponding to approximately 40,000 unit cells, were aligned by a minimal phase residual search and merged by vector addition in reciprocal space. Phases from the resulting composite transform were combined with amplitudes from electron diffraction patterns to reconstruct the projected mass density of the gp32*I crystal at 8.4 A resolution.     

Enhanced plasma ghrelin levels in rats with streptozotocin-induced diabetes

Human saliva, which contains nitrite, is normally mixed with gastric juice, which contains ascorbic acid (AA). When saliva was mixed with an acidic buffer in the presence of 0.1 mM AA, rapid nitric oxide formation and oxygen uptake were observed. The oxygen uptake was due to the oxidation of nitric oxide, which was formed by AA-dependent reduction of nitrite under acidic conditions, by molecular oxygen. A salivary component SCN⁻ enhanced the nitric oxide formation and oxygen uptake by the AA/nitrite system. The oxygen uptake by the AA/nitrite/SCN⁻ system was also observed in an acidic buffer solution. These results suggest that oxygen is normally taken up in the stomach when saliva and gastric juice are mixed.     

Biogeographical variation in the diet of Holarctic martens (genus Martes,Mammalia: Carnivora: Mustelidae): adaptive foraging in generalists

Aim Studies comparing feeding habits across a genus in different geographical regions or habitats can identify factors associated with adaptive feeding behaviour, linking key ecological traits between consumers and their environment. We investigated biogeographical patterns in dietary composition and trophic diversity across the genus Martes in relation to geographical range and environmental variables. We hypothesized that widely distributed opportunistic Martes species should demonstrate adaptive variations in dietary composition and trophic diversity relative to regional geographical location (e.g. latitude, elevation), environmental variation (e.g. temperature, rainfall, snow cover and primary productivity) and concomitant variation in food supply. Location Europe, Asia and North America. Methods We examined the dietary habits of martens (Martes spp.) using original data expressed as relative frequency of occurrence, and using principal components analysis to extract the main gradients in diet composition. These were then used as response variables in regression analyses, predicted from latitude or elevation. Multiple regression analyses were performed to assess the influence of food types and environmental variables on the trophic diversity index. Results A clear latitudinal gradient in dietary composition was observed. Small mammals were the primary food type, but were less abundant in the diet of martens at lower latitude and elevation. Vegetable matter and insects were consumed more frequently in southerly and/or lower‐elevation localities. Trophic diversity was lower at higher elevation, and increased with a decline in consumption of the dominant food types, i.e. rodents, fruits and insects. Trophic diversity also increased with increasing mean temperature. Main conclusions Biogeographical variations in feeding habits across the genus Martes proved to be associated with latitude, local climate (especially temperature regime) and the availability of alternative potential foods. On an extensive geographical scale, martens respond to varying food availability by adjusting their foraging strategy and thus should be considered facultative generalists. At the species level, however, different climatic variables emerged as differentially important, indicative of adaptations to local conditions. Martes species are opportunistic and flexible feeders, and thus their conservation requires informed management, mindful of how changes in environmental conditions might influence their varied food supply.     

Potential Measurement Errors Due to Image Enlargement in Optical Coherence Tomography Imaging

The effect of interpolation and super-resolution (SR) algorithms on quantitative and qualitative assessments of enlarged optical coherence tomography (OCT) images was investigated in this report. Spectral-domain OCT images from 30 eyes in 30 consecutive patients with diabetic macular edema (DME) and 20 healthy eyes in 20 consecutive volunteers were analyzed. Original image (OR) resolution was reduced by a factor of four. Images were then magnified by a factor of four with and without application of one of the following algorithms: bilinear (BL), bicubic (BC), Lanczos3 (LA), and SR. Differences in peak signal-to-noise ratio (PSNR), retinal nerve fiber layer (RNFL) thickness, photoreceptor layer status, and parallelism (reflects the complexity of photoreceptor layer alterations) were analyzed in each image type. The order of PSNRs from highest to lowest was SR > LA > BC > BL > non-processed enlarged images (NONE). The PSNR was statistically different in all groups. The NONE, BC, and LA images resulted in significantly thicker RNFL measurements than the OR image. In eyes with DME, the photoreceptor layer, which was hardly identifiable in NONE images, became detectable with algorithm application. However, OCT photoreceptor parameters were still assessed as more undetectable than in OR images. Parallelism was not statistically different in OR and NONE images, but other image groups had significantly higher parallelism than OR images. Our results indicated that interpolation and SR algorithms increased OCT image resolution. However, qualitative and quantitative assessments were influenced by algorithm use. Additionally, each algorithm affected the assessments differently.     

Production and characterization of monoclonal antibodies to 17 alpha-hydroxyprogesterone

Hybridoma clones producing antibodies to 17 alpha-hydroxyprogesterone (17-OHP) were established by using a 17-OHP-bovine serum albumin conjugate as an immunogen. Six representative IgG-class monoclonal antibodies of high affinity (10(8)-10(9) M-1) showed differential reactivities with several structurally related steroids. Two enzyme immunoassay (EIA) systems (fluorescence EIA and micro-EIA) for 17-OHP using OHP 4B2.2.3, which showed the lowest cross-reactivity with other steroids, were established. The micro-EIA system was shown to be applicable to the mass-screening of congenital adrenal hyperplasia.     

Immunochemical Studies on Ribulose 1,5-Bisphosphate Carboxylase/Oxygenase in the Chloroplasts of the Marine Alga Bryopsis maxima

The localization of ribulose 1,5-bisphosphate carboxylase/oxygenase(RuBisCO) in chloroplasts of the green alga Bryopsis maximawas examined by immunological techniques. Three strains of hybridomaswere established between myeloma cells and the spleen cellsfrom mouse immunized against B. maxima RuBisCO. The antibodiesreacted with the large subunit of B. maxima RuBisCO but notwith spinach RuBisCO. Immunofluorescence and immunoenzymaticstudies showed that the large subunit of B. maxima RuBisCO wasconcentrated in pyrenoids and on the surface of starch grainssurrounding the pyrenoids. (Received September 22, 1987; Accepted March 2, 1988)     

Usefulness of multiple chalk‐based food colorings for inducing better gene silencing by feeding RNA interference in planarians

Planarians have become widely recognized as one of the major animal models for regeneration studies in invertebrates. To induce RNA interference (RNAi) by feeding in planarians, the widely accepted protocol is one in which animals undergo two or three feedings of food containing double‐stranded RNA (dsRNA) plus visible food coloring (e.g., blood) for confirmation of feeding by individual animals. However, one possible problem is that incorporated food coloring is often retained within the gut for several days, which makes it difficult to confirm the success of each round of dsRNA feeding based on the difference of the color density within the gut before and after feeding. As a consequence, the difference of appetite levels among individuals undergoing dsRNA feeding leads to phenotypic variability among them due to insufficient knockdown. In our attempts to overcome this problem, we have developed a novel method for achieving robust confirmation of the success of dsRNA feeding in individuals fed multiple times by means of including a combination of three different colored chalks (pink, yellow and blue) as food coloring. Notably, we found that this method is superior to the conventional method for positively marking individuals that actively consumed the dsRNA‐containing food during four times of once‐daily feeding. Using these selected animals, we obtained stable and sufficiently strong RNAi‐induced phenotypes. We termed this improved multi‐colored chalk‐spiked method of feeding RNAi “Candi” and propose its benefits for gene function analysis in planarians.